JP7298489B2 - engine intake system - Google Patents

Description

The present invention relates to an intake system for an engine having an intercooler in the middle of an intake passage.

BACKGROUND ART An engine intake device is known that has an intercooler in the middle of an intake passage that supplies intake air to an engine body. The intercooler includes a chamber and an intercooler core housed in the chamber. Intake systems with intercoolers are sometimes required to have a compact layout. Patent Literature 1 discloses an intake system in which an intake manifold and an intercooler chamber are integrated as a unit. This intake system discloses an intake system in which a downstream intake passage located downstream of the chamber extends upward from an upper portion of a downstream space of an intercooler core and communicates with an intake manifold.

JP 2013-147952 A

Intake systems with intercoolers are sometimes required to have a compact layout. Due to this layout constraint, the intake air delivery opening that delivers the intake air from the intercooler chamber to the downstream intake passage may have to be located near the lower end of the downstream sidewall of said chamber. On the other hand, in an intercooler, it is desirable to improve the dispersion of intake air so that the intake air evenly passes through the entire area of the intercooler core. However, if the intake air delivery openings are located unevenly at the lower end of the chamber, uneven intake flow is likely to be formed. In this case, the intake air cannot be cooled by making use of the entire volume of the intercooler core, and the problem arises that the intercooler cannot exhibit sufficient intake air cooling performance.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an engine air intake system in which the intake air is dispersed more efficiently in the intercooler core and the intake air cooling performance of the intercooler is improved.

An intake system for an engine according to one aspect of the present invention includes an intercooler including a chamber and an intercooler core housed inside the chamber; a downstream intake passage located downstream of the chamber; an intake passage that guides intake air to the engine body through the intercooler core in the chamber, the chamber being a space adjacent to the downstream side of the intercooler core and communicating with the downstream intake passage; a downstream side wall that defines the space of the downstream chamber facing the side surface; and a core holding portion that holds an upper end surface of the intercooler core, the downstream side wall being disposed near the lower end thereof to hold the intercooler core. An intake air delivery opening for delivering passing intake air to the downstream intake passage, and an expansion partition section for partitioning an expansion space for expanding the space of the downstream chamber above the lower end of the core holding section.

In this intake device, the intake air delivery opening is located near the lower end of the downstream side wall of the chamber. Therefore, the intake air flow passing through the intercooler core is likely to be directed to the intake air delivery opening near the lower end. Therefore, it tends to be difficult for the intake air to pass through the region on the downstream side and above the intercooler core. However, according to the intake device described above, since the expansion space is provided for expanding the space of the downstream chamber upward, the ventilation resistance in the vicinity of the upper end of the downstream chamber can be reduced. This makes it easier to form an intake air flow in the region above and downstream of the intercooler core, thereby enhancing the dispersion of intake air in the intercooler core.

In general, a core holder that holds an intercooler core does not have air permeability. For this reason, for example, if the intake air delivery opening of the chamber has a large diameter that opens all over the intercooler core, or if the intake air delivery opening is provided above the chamber as in the intake device of Patent Document 1, In this case, there is no need to expand the space of the downstream chamber above the lower end of the core holding portion. However, in the present invention, under the constraint that the intake air delivery opening is unevenly provided at the lower end of the chamber, the expansion space for expanding the space of the downstream chamber above the lower end of the core holding portion is provided. I set it up on purpose. This makes it easier for the intake air to spread even to the downstream side and upper region of the intercooler core where it is difficult to form an intake air flow due to the above restrictions.

In the intake device for the engine described above, it is preferable that the downstream intake passage includes an extension passage extending upward along the downstream side wall of the chamber.

According to this intake device, the extension passage portion is provided using the downstream side wall of the chamber. Therefore, it becomes easy to secure a sufficient intake passage length downstream of the intercooler, and the intake air flow can be guided to the engine main body (intake manifold) in a rectified state.

In the intake device for the engine described above, it is preferable that the downstream side wall divides the space of the downstream chamber such that the distance from the downstream side surface of the intercooler core increases downward.

According to this intake device, the width of the downstream chamber widens toward the intake air delivery opening arranged near the lower end of the downstream side wall. Therefore, it is possible to reduce ventilation resistance when the intake air that has passed through the upper region of the intercooler core is directed toward the intake air delivery opening. Therefore, the intake air can be easily sent out smoothly from the entire area of the intercooler core to the downstream side intake passage.

In the above engine air intake device, the chamber has a bottom wall positioned below the intercooler core, and the bottom wall has a bottom opening that opens at a position corresponding to the downstream chamber and closes the bottom opening. and a lid member.

According to this air intake device, it is possible to dispose a sliding mold for forming the expansion compartment through the bottom opening during molding of the chamber. Accordingly, molding of the chamber containing the expansion compartment can be facilitated. Further, by covering the lower surface opening with a lid member, it is possible to ensure the airtightness of the chamber.

In this case, it is desirable that the lid member has a cavity that extends downward the space of the downstream chamber.

According to this air intake device, since the downstream chamber is expanded downward, the ventilation resistance in the vicinity of the intake air delivery opening can be reduced, and the dispersion of the intake air can be further enhanced. Also, the cavity of the lid member can be used as a space for storing condensed water generated in the downstream intake passage.

In the above engine intake device, the chamber further includes an upstream intake passage located upstream of the chamber, and the upstream intake passage guides intake air into the chamber. It is desirable that the intake air introducing portion is arranged to face an upper region of the intercooler core.

According to this intake device, in a side view in a direction perpendicular to the airflow direction of the intercooler core, the intake air introduction portion (upper) and the intake air delivery opening (lower) are positioned diagonally of the intercooler core. Such a layout can be said to be a layout in which the intake air is more difficult to disperse in the area downstream and above the intercooler core. However, according to the present invention, the expansion space is provided in the downstream chamber, so even with this layout, the air intake to the intercooler core can be dispersed satisfactorily.

Advantageous Effects of Invention According to the present invention, it is possible to provide an engine air intake device in which the intake air is dispersed more efficiently in the intercooler core and the intake air cooling performance of the intercooler is improved.

FIG. 1 is an engine system diagram of an engine to which an intake system according to an embodiment of the present invention is applied. FIG. 2 is a schematic perspective view showing the appearance of an engine to which an intake system according to an embodiment of the invention is applied. FIG. 3 is a front view of the intake device according to the embodiment of the invention. 4 is a cross-sectional view taken along line IV-IV of FIG. 3. FIG. 5 is a cross-sectional view taken along the line VV of FIG. 3. FIG. FIG. 6 is a sectional view taken along line VI-VI of FIG. 7 is an enlarged view of a main portion of FIG. 5, and a cross-sectional view taken along the line VII-VII of FIG. 4. FIG. FIG. 8 is a perspective view of the bottom cover member of the chamber; 9 is a cross-sectional view taken along line IX-IX of FIG. 4. FIG. 10 is a cross-sectional view taken along the line XX of FIG. 4. FIG. FIG. 11 is a cross-sectional view schematically showing how the expansion space is formed. FIG. 12 is an enlarged view of the main part of FIG. 5, showing the intake air flow passing through the intercooler. FIG. 13 is a schematic diagram for explaining the flow of intake air in the chamber according to the comparative example. FIG. 14 is a schematic diagram for explaining the flow of intake air in the chamber according to the modification of this embodiment. FIG. 15 is a schematic diagram for explaining the flow of intake air in the chamber according to this embodiment.

[Overall structure of the engine]
DETAILED DESCRIPTION OF THE INVENTION An intake system for an engine according to the present invention will be described in detail below with reference to the drawings. First, with reference to the system diagram shown in FIG. 1, the overall configuration of an engine system S to which an intake device for an engine according to the present invention is applied will be described. The engine system S shown in FIG. 1 is a 4-cycle multi-cylinder turbocharged gasoline engine mounted on a vehicle as a power source for running. The drive system of the engine can be FF or FR.

The engine system S includes an engine body 1, an intake passage 20 that guides outside air (intake) to the engine body 1, an exhaust passage 30 through which exhaust gas discharged from the engine body 1 flows, and an exhaust gas flowing through the exhaust passage 30. An EGR device 36 that recirculates a portion of the gas as EGR gas to the intake passage 20 , an intercooler 23 arranged in the intake passage 20 , and a blow-by recirculation device 16 that recirculates the blow-by gas to the intake passage 20 . In this embodiment, the intake passage 20 and the intercooler 23 described above constitute the intake device according to the present invention.

The engine body 1 includes a cylinder block 3 in which a cylinder 2 is formed, a cylinder head 4 attached to the upper surface of the cylinder block 3 so as to block the cylinder 2 from above, and a piston 5 accommodated in the cylinder 2. and The engine body 1 is of a multi-cylinder type having, for example, four cylinders, but only one cylinder 2 is shown in FIG. 1 for the sake of simplification. A piston 5 is accommodated in the cylinder 2 so as to be able to reciprocate with a predetermined stroke. A crankshaft 7 that is an output shaft of the engine body 1 is provided below the piston 5 . The crankshaft 7 is connected to the piston 5 via a connecting rod 8 and is driven to rotate about the central axis according to the reciprocating motion of the piston 5 .

A combustion chamber 6 is defined above the piston 5 . A combustion chamber 6 is formed by the lower surface of the cylinder head 4 and the crown surfaces of the cylinders 2 and the pistons 5 . The cylinder head 4 has an injector 13 for injecting fuel (mainly gasoline) into the combustion chamber 6, and a mixture of the fuel injected from the injector 13 into the combustion chamber 6 and the air introduced into the combustion chamber 6. A spark plug 14 for igniting is provided. The air-fuel mixture is combusted in the combustion chamber 6, and the piston 5 pushed down by the expansion force of the combustion reciprocates vertically.

An intake port 9 and an exhaust port 10 communicating with the combustion chamber 6 are formed in the cylinder head 4 . An intake side opening, which is the downstream end of the intake port 9 , and an exhaust side opening, which is the upstream end of the exhaust port 10 , are formed on the lower surface of the cylinder head 4 . The cylinder head 4 is assembled with an intake valve 11 that opens and closes the intake side opening and an exhaust valve 12 that opens and closes the exhaust side opening.

The intake passage 20 is a path that communicates with the intake port 9 and supplies intake air to each cylinder 2 through the intercooler 23 . Air taken in from the upstream end of the intake passage 20 is introduced into the combustion chamber 6 through the intake passage 20 and the intake port 9 . In the intake passage 20, an air cleaner 21, a turbocharger 15, a valve unit 26 and an intercooler 23 are arranged in this order from the upstream side.

The air cleaner 21 cleans the intake air by removing foreign substances in the intake air. Valve unit 26 includes throttle valve 261 . The throttle valve 261 opens and closes the intake passage 20 in conjunction with the depression of an accelerator (not shown) to adjust the flow rate of intake air in the intake passage 20 . The turbocharger 15 sends out the intake air to the downstream side of the intake passage 20 while compressing the intake air.

The intercooler 23 cools the intake air compressed by the turbocharger 15 . The intercooler 23 is water-cooled and includes a chamber 51 inserted into the intake passage 20 and an intercooler core 52 housed inside the chamber 51 . The intake passage 20 guides intake air to the engine body 1 through an intercooler core 52 inside a chamber 51 . The intake passage 20 includes an upstream intake passage 22 located upstream of the chamber 51 and a downstream intake passage 24 located downstream of the chamber 51 . A downstream end of the downstream intake passage 24 is connected to an independent intake passage 25 provided in the intake manifold. A surge tank 251 that provides a space for evenly distributing intake air to the plurality of cylinders 2 is arranged immediately upstream of the independent intake passage 25 .

The exhaust passage 30 communicates with the exhaust port 10 and discharges the burned gas (exhaust gas) generated in the combustion chamber 6 to the outside of the vehicle. The exhaust passage 30 includes an upstream exhaust passage 31 and a downstream exhaust passage 34, between which an upstream catalytic converter 32 and a downstream catalytic converter 33 are provided. The upstream catalytic converter 32 includes a three-way catalyst for purifying harmful components (HC, CO, NOx) contained in the exhaust gas, and a three-way catalyst for collecting particulate matter (PM) contained in the exhaust gas. GPF (gasoline particulate filter) is built in. The downstream catalytic converter 33 incorporates an appropriate catalyst such as a three-way catalyst or a NOx catalyst. A muffler 35 is attached to the downstream end of the downstream exhaust passage 34 .

The turbocharger 15 includes a compressor 151 arranged on the intake passage 20 side and a turbine 152 arranged on the exhaust passage 30 . The turbine 152 rotates by receiving the energy of the exhaust gas flowing through the exhaust passage 30 . As the compressor 151 rotates in conjunction with this, the air flowing through the intake passage 20 is compressed (supercharged).

The blow-by reflux device 16 includes a blow-by inlet 161 , a blow-by pipe 162 and a blow-by inlet 163 . The blow-by intake 161 takes in blow-by gas, which is an unburned air-fuel mixture that flows out from the cylinder 2 to the surroundings when the engine body 1 is operating. The blow-by pipe 162 is a pipe that connects the blow-by inlet 161 and the blow-by inlet 163 . The blow-by introduction port 163 is an opening that is arranged so as to communicate with a suitable portion of the downstream intake passage 24 and allows blow-by gas to flow back into the downstream intake passage 24 .

The EGR device 36 is a device that realizes so-called high-pressure EGR, and includes an EGR passage 361 , an EGR cooler 362 and an EGR valve 363 . EGR passage 361 connects exhaust passage 30 and intake passage 20 . Specifically, the upstream exhaust passage 31 located upstream of the turbocharger 15 and the downstream intake passage 24 located downstream of the intercooler 23 are connected. The EGR cooler 362 cools the exhaust gas (EGR gas) recirculated from the exhaust passage 30 to the intake passage 20 by heat exchange. The EGR valve 363 adjusts the flow rate of exhaust gas flowing through the EGR passage 361 . Note that the EGR gas recirculated by the EGR device 36 and the blow-by gas described above are gases that easily generate condensed water.

In the present embodiment, an intake unit 40 (engine intake device) is formed by integrating part of the intake system and the intercooler 23 , and the intake unit 40 is attached to the engine body 1 . The parts included in the intake unit 40 are the passage downstream of the valve unit 26 in the upstream intake passage 22, the intercooler 23, the downstream intake passage 24, the surge tank 251, the independent intake passage 25 as an intake manifold, and the downstream of the EGR passage 361. Part and blow-by inlet 163 .

[External structure of the engine]
2 is a schematic perspective view showing the appearance of the engine body 1 to which the intake unit 40 is attached, and FIG. 3 is a front view of the intake unit 40 alone. In FIGS. 2, 3 and other figures, front/rear, left/right, and up/down directions are indicated. These directional indications are for convenience of explanation and do not necessarily match the actual directions and are not intended to limit the present invention.

The intake unit 40 is attached to the front side surface of the engine body 1 . The intake unit 40 includes an intake housing 41 that forms part of an intake passage through which intake air introduced into the engine body 1 flows. 2 and 3 of the intake housing 41, an upper and lower passage portion 431 that partitions the intake passage 24 on the downstream side of the intake passage 20 described above, an intake manifold portion 432 that partitions the independent intake passage 25, and an EGR passage 361. A bulge 433 is shown that defines the downstream portion of the .

The intercooler 23 is arranged such that its front surface and upper surface are surrounded by the upper and lower passage portions 431 and the intake manifold portion 432 . The chamber 51 of the intercooler 23 described above forms part of the intake housing 41 . The intercooler core 52 can be inserted leftward into the intake housing 41 and pulled out rightward. A valve unit 26 serving as an intake inlet to the intake unit 40 is arranged on the right side of the intercooler 23 . An EGR cooler 362 and an EGR valve 363 of the EGR device 36 are assembled on the upper portion of the intake manifold portion 432 .

[Internal structure of intake unit]
Next, the internal structure of the air intake unit 40 will be described. 4 is a sectional view taken along line IV-IV in FIG. 3, FIG. 5 is a sectional view taken along line VV in FIG. 3, FIG. 6 is a sectional view taken along line VI-VI in FIG. 5 is an enlarged view of a part and a cross-sectional view taken along line VII-VII of FIG. 4; FIG. The intake housing 41 is composed of a combination of an inner housing 42 on the rear side and an outer housing 43 on the front side. Both housings 42 and 43 are connected by welding, screwing, or the like. In FIG. 7, a flange portion 42F of the inner housing 42 and a flange portion 43F of the outer housing 43 are butt-connected near the lower end of the intake housing 41. In FIG. is shown.

A chamber 51 of the intercooler 23 is formed in the inner housing 42 . The chamber 51 defines a substantially rectangular parallelepiped space that accommodates the intercooler core 52 . The chamber 51 is generally defined by an upstream sidewall 511, a bottom wall 512, a top wall 513, a downstream sidewall 514, a right wall 515 and a left wall 516, and these walls 511-516 form the top, bottom and bottom walls of the intercooler core 52. They face the rear side (upstream side 52A), the front side (downstream side 52B), the right side, and the left side.

A rectangular parallelepiped intercooler core 52 is accommodated in the chamber 51, and spaces of an upstream chamber 51A and a downstream chamber 51B are formed. The intercooler core 52 is of a water-cooled plate type, and is composed of a plurality of plates in which meandering cooling water flow passages through which cooling water flows are formed, and cooling fins sandwiched between these plates. It is the core structure. The intercooler core 52 is provided with a cooling water circulation system including a water pump and a radiator (not shown).

The upstream side wall 511 is a side wall on the rear side of the chamber 51 and is positioned on the upstream side of the intake air flowing through the intake passage 20 , that is, on the inlet side of the chamber 51 . The downstream side wall 514 is a side wall on the front side (downstream side) of the chamber 51 and is a side wall located on the outlet side of the chamber 51 . Note that the upstream side wall 511 is a wall attached to the body portion of the chamber 51 afterward. A portion of the downstream side wall 514 is formed by the bottom cover member 53 that is attached later.

The bottom wall 512 and the top wall 513 are walls that define the bottom and top surfaces of the chamber 51, respectively. A right wall 515 and a left wall 516 are walls that separate the right side and left side of the chamber 51, respectively. The right wall 515 (opposing side wall) is a wall that connects the right end portion of the upstream side wall 511 and the right end portion of the downstream side wall 514, and is a side wall that faces an intake air introduction portion 22A, which will be described later.

As schematically shown in FIG. 7, the intercooler core 52 is constantly provided with core holding portions on the upper end side and the lower end side. That is, an upper core holding portion 521 that holds the upper surface of the body portion of the intercooler core 52 is attached to the upper surface of the body portion. A lower core holding portion 522 is attached to the lower surface of the main body portion to hold the lower surface. As described above, the intercooler core 52 can be inserted into and removed from the chamber 51, and the upper core holding portion 521 and the lower core holding portion 522 are formed with guide portions for facilitating the insertion and removal. Note that the upper core holding portion 521 and the lower core holding portion 522 are portions that do not have air permeability, unlike the body portion of the intercooler core 52 .

A sealing member 52S is attached to the upper surface of the upper core holding portion 521 and the bottom surface of the lower core holding portion 522 to prevent leakage of the intake air flow. The sealing member 52S seals the gap between the bottom wall 512 of the chamber 51 and the bottom surface of the intercooler core 52 and the gap between the top wall 513 and the top surface of the intercooler core 52, respectively. The sealing member 52S is a lip seal. 5 and 7 show the state in which the lip portion of the sealing member 52S is stretched, but in reality the lip portion is crushed to close the gap. The interposition of the seal member 52S prevents the intake air from flowing downstream without passing through the intercooler core 52 .

The upstream chamber 51A is a space adjacent to an upstream side surface 52A ( FIG. 7 ) of the intercooler core 52 and communicates with the upstream intake passage 22 . The upstream side wall 511 faces the upstream side surface 52A of the intercooler core 52 with a predetermined gap, and defines the space of the upstream chamber 51A. The downstream chamber 51B is a space adjacent to the downstream side surface 52B of the intercooler core 52 and communicates with the downstream intake passage 24 . The downstream side wall 514 faces the downstream side surface 52B of the intercooler core 52 with a predetermined gap, and defines the space of the downstream chamber 51B. Intake air flows from the upstream side intake passage 22 into the upstream chamber 51A, passes through the intercooler core 52, enters the downstream chamber 51B, and is sent out to the downstream side intake passage 24 thereafter.

The upstream side wall 511 includes a non-uniform flow rib 60 (a non-uniform flow portion) and a flow rate adjusting portion 70 . As shown in FIG. 7, the drift rib 60 extends vertically in a region overlapping the introduction port 220 of the intake introduction portion 22A in the height direction, and protrudes into the space of the upstream chamber 51A. As shown in FIG. 4, the flow rate adjusting portion 70 projects toward the upstream side surface 52A of the intercooler core 52 at a position (left side) farther than the drift rib 60 with respect to the intake air introducing portion 22A, and the space of the upstream chamber 51A. It is a member that narrows the

The downstream side wall 514 includes an expansion compartment 514A that defines the expansion space 80, as shown in FIGS. The expansion space 80 is a space that expands the space of the downstream chamber 51</b>B above the lower end portion 523 of the upper core holding portion 521 . The expansion partition 514A partitions the expansion space 80 together with the upper wall extension 513A located on the front end side of the upper wall 513. As shown in FIG. The structure of these upstream sidewalls 511 and downstream sidewalls 514 will be described in further detail below.

Referring to FIG. 4, an air intake unit 40 is integrally provided with an air intake introduction portion 22A. The intake air introducing portion 22A is a portion of the upstream intake passage 22 located downstream of the valve unit 26 . The intake air introduction portion 22A includes an introduction port 220, a first portion 221 and a second portion 222, and forms a passage having a crank shape when viewed from above. The intake air introducing portion 22A communicates with the upstream chamber 51A. The intake air introduction part 22A guides the intake air to the chamber 51 from a direction orthogonal (crossing) to the direction in which the intake air passes through the intercooler core 52 .

The inlet 220 is an opening on the right side of the valve unit 26 and serves as an intake inlet to the intake unit 40 . The opening axis of the introduction port 220 is oriented in the left-right direction orthogonal to the front-rear direction, which is the direction in which the intake air passes through the intercooler core 52 . The first portion 221 is a passage extending leftward from the inlet 220 toward the right wall 515 (opposing side wall) of the chamber 51 . As schematically shown in FIG. 7, the introduction port 220 and the first portion 221 are located above the intercooler core 52 and closer to the front. The second portion 222 is a passage that extends rearward from the downstream end of the first portion 221 along the right wall 515 and communicates with the right end of the upstream chamber 51A. The second portion 222 has the same vertical width as the upstream chamber 51A at its downstream end (rear end).

On the other hand, as an outlet for the intake air from the chamber 51, the downstream side wall 514 is provided with an intake air delivery opening 54 for delivering the intake air from the chamber 51 to the downstream side. The intake air delivery opening 54 is arranged at a position corresponding to the lower end region of the chamber 51 (near the lower end of the downstream side wall 514). The intake air delivery opening 54 is an opening through which the intake air that has been introduced into the chamber 51 and passed through the intercooler core 52 is collected and delivered to the downstream intake passage 24 . Here, "intensive" delivery means that the outlet side of the chamber 51 is entirely open and the intake air is not delivered randomly. In this embodiment, the outlet opening of the intake air from the chamber 51 is limited to the range of the intake air delivery opening 54 (FIG. 6) having a substantially semicircular cross section formed near the lower end of the downstream side wall 514, and the limited opening is Sends the inspiratory air out of the area as a cohesive stream.

A bottom opening 55 is provided on the bottom side of the chamber 51 . Specifically, the lower surface opening 55 opens in the bottom wall 512 at a position corresponding to the downstream chamber 51B. As shown in FIG. 6, the lower surface opening 55 is arranged at a position that overlaps in the vertical direction with a region from near the downstream (near the front) of the position where the intercooler core 52 is arranged in the chamber 51 to the position where the intake air delivery opening 54 is arranged. ing. The lower surface opening 55 is used as an opening for inserting and removing a slide mold when molding the chamber 51 (described later with reference to FIG. 11).

The bottom surface opening 55 is closed by the bottom lid member 53 . In this embodiment, the bottom lid member 53 serves as a reservoir for condensed water generated in the intake passage 20 (downstream intake passage 24). In other words, the bottom lid member 53 has a storage recess 531 that stores the condensed water. The reservoir recess 531 is a cavity with an open upper surface. This cavity expands the space of the downstream chamber 51B downward. As described above, EGR gas and blow-by gas, which tend to generate condensed water, are introduced into the downstream intake passage 24 . The cavity of the storage concave portion 531 is set to have a volume capable of storing a predetermined amount of condensed water. The stored condensed water is successively carried out to the downstream side intake passage 24 by the intake flow passing through the intercooler core 52 .

8 is a perspective view of the bottom lid member 53. FIG. An arrow a shown in FIG. 8 indicates the flow direction of the intake air flowing from the chamber 51 toward the downstream intake passage 24 . The bottom lid member 53 has a first rib 532 , a second rib 533 , a communication groove 534 , a pair of side ribs 535 and 536 , an upstream wall 537 and a downstream wall 538 in addition to the storage recess 531 described above.

Both the first rib 532 and the second rib 533 are ribs that protrude upward from the bottom surface of the cavity of the storage recess 531 . The first rib 532 is a rib extending back and forth along the direction of intake air flow. The second rib 533 extends in a direction orthogonal (crossing) to the direction of the intake air flow. The communication grooves 534 are grooves that allow the movement of stored condensed water between the small sections generated in the cavity by the parallel arrangement of the plurality of first ribs 532 in order to stabilize the water level of the condensed water. be. One side rib 535 and the other side rib 536 are ribs erected upward from the periphery of the storage recess 531 on the left end side of the bottom lid member 53 and on the right end side, respectively.

An upstream wall 537 defines the rear surface of the cavity of the reservoir recess 531 . The downstream wall 538 is a wall that defines the front surface of the cavity and has a portion that extends upward from the periphery of the reservoir recess 531 . A semicircular cutout edge 53A corresponding to the lower edge of the intake air delivery opening 54 is provided in the upwardly extending portion of the downstream wall 538 . A flange portion 539 is provided on the peripheral edge of the storage recessed portion 531 . This flange portion 539 abuts against the peripheral edge portion of the bottom opening 55 in the bottom wall 512 and is fixed by welding or the like.

Returning to FIG. 5 , the outer housing 43 includes an upper and lower passage portion 431 , an intake manifold portion 432 and a swelling portion 433 . The vertical passage portion 431 extends linearly in the vertical direction and defines a passage having a semicircular cross section. A lower end portion 434 of the upper and lower passage portion 431 is arranged at a position facing the intake air delivery opening 54 . The upper end of the upper and lower passage portion 431 communicates with the intake manifold portion 432 in a manner that curves rearward.

The intake manifold portion 432 is a portion that forms a path for distributing intake air to the plurality of cylinders 2 provided in the engine body 1, and has a plurality of independent intake passages 25 shown in FIG. The bulging portion 433 is a portion of the front side wall portion (the outer wall portion 244 ) of the vertical passage portion 431 that bulges in the vertical direction along the vertical passage portion 431 . Referring to FIG. 3 , bulging portion 433 is arranged near the center of upper and lower passage portion 431 in the left-right direction. The bulging portion 433 has a bifurcated downstream end 433E bifurcated to the left and right at its lower end. From the bifurcated downstream end 433E, a left channel portion 433L and a right channel portion 433R extend leftward and rightward, respectively, along the outer periphery of the outer wall portion 244 having a semicircular cross section.

As shown in FIG. 5 , the downstream intake passage 24 has an upstream end 241 connected to the intake air delivery opening 54 and an extension passage portion 242 extending upward from the upstream end 241 . The upstream end 241 is the portion immediately downstream of the intake air delivery opening 54 defined by members near the forward lower end of the inner housing 42 . The extension passage portion 242 extends upward from the upstream end 241 along the downstream side wall 514 of the chamber 51 and continues to the surge tank 251 . The upstream portion of the extension passage portion 242 that continues to the upstream end 241 is a passage curved about 90 degrees upward and forward. A downstream portion of the extension passage portion 242 connected to the surge tank 251 is a passage curved obliquely upward to the rear.

The upper and lower passage portions 431 define the extension passage portion 242 together with a portion of the inner housing 42 . The extension passage portion 242 is partitioned by an inner wall portion 243 located on the chamber 51 side and an outer wall portion 244 facing the inner wall portion 243 . The bulging portion 433 defines a downstream portion of the EGR passage 361 (portion downstream of the EGR valve 363 ) extending vertically on the front side of the extension passage portion 242 . A pair of left and right EGR introduction ports 45 for joining the EGR passage 361 to the downstream side intake passage 24 are opened in the lower end region of the upper and lower passage portions 431 . The left channel portion 433</b>L and the right channel portion 433</b>R form passages for introducing EGR gas to the EGR inlets 45 . Further, a blow-by inlet 163 for recirculating the blow-by gas to the downstream side intake passage 24 is opened in the lower end region of the upper and lower passage portion 431 and slightly above the EGR inlet 45 .

[Details of upstream wall]
Next, the upstream side wall 511 that defines the space of the upstream chamber 51A in the chamber 51 of the intercooler 23 will be described in detail with reference to FIGS. 9 and 10 in addition to FIGS. 9 is a sectional view taken along line IX-IX of FIG. 4, and FIG. 10 is a sectional view taken along line XX of FIG. As described above, it includes the drift rib 60 arranged near the right end near the intake air introduction portion 22A, and the flow rate adjusting portion 70 located farther than the drift rib 60 with respect to the intake air introduction portion 22A.

The drift rib 60 includes a flat rib body 61 and a lower end portion 62 that is the lower end of the rib body 61 . The non-uniform flow rib 60 is arranged to direct the intake air flowing into the upstream chamber 51A from the chamber inlet 510 (FIG. 4) to the intercooler core 52 through the crank-shaped intake air introduction portion 22A. The drift rib 60 protrudes from the inner wall surface of the upstream side wall 511 in the vicinity of the chamber inlet 510 . The non-uniform flow rib 60 projects forward and stands perpendicular to the inner wall surface. Moreover, the drift rib 60 extends linearly in the vertical direction. The chamber inlet 510 is an opening provided on the rear end side of the right wall 515 and is an opening through which the intake air sent from the intake air introducing portion 22</b>A enters the chamber 51 . The chamber inlet 510 has a vertical width substantially equal to the vertical width of the intercooler core 52 (FIG. 7).

In this embodiment, the lateral flow rib 60 is arranged at a position about 1/6 of the lateral width of the upstream chamber 51A from the chamber inlet 510. As shown in FIG. If the arrangement position is too close to the chamber inlet 510, the inflow of the intake air to the upstream chamber 51A will tend to be blocked. For this reason, it is desirable to select the arrangement position of the drift rib 60 in the lateral direction from the range of about ⅓ to ⅛ of the lateral width of the upstream chamber 51A from the chamber inlet 510. FIG.

In this embodiment, the vertical width of the drift rib 60 is about half the vertical width of the upstream chamber 51A, as shown in FIG. That is, the drift rib 60 extends downward from the upper end of the upstream chamber 51A, and is erected on the upstream side wall 511 such that the lower end portion 62 is positioned approximately at the middle point of the upstream chamber 51A in the vertical direction. This is due to the fact that of the intake air flowing in from the chamber inlet 510, the intake air that enters the upper region of the upstream chamber 51A is intended to be blown against the drift rib 60 and directed toward the upstream side surface 52A of the intercooler core 52. . The vertical position of the drift rib 60 also corresponds to the height position of the introduction port 220 (FIG. 7) of the intake air introduction portion 22A. In this embodiment, the lower end portion 62 extends to a height position corresponding to an upper end portion 71A of a projecting wall 71 of the flow rate adjusting portion 70, which will be described later.

If the position of the lower end portion 62 of the drift rib 60 extends excessively below the upstream chamber 51A, it tends to be difficult for the intake air flow to enter the upstream chamber 51A to the far left. On the other hand, if the position of the lower end portion 62 is too high, the effect of guiding the intake air flow to the intercooler core 52 tends to weaken. Therefore, it is desirable to set the position of the lower end portion 62 of the drift rib 60 within a range of about 1/4 to 3/4 of the vertical width of the upstream chamber 51A from the upper end of the upstream chamber 51A. Moreover, it is desirable to set the standing height of the rib main body 61 within a range of about 1/4 to 3/4 of the front-to-rear width of the upstream chamber 51A.

The flow rate adjusting unit 70 is arranged to partially narrow the space of the upstream chamber 51A and increase the resistance of the intake air flow in that portion. In this embodiment, the flow rate adjusting portion 70 includes a projecting wall 71 projecting forward from the inner wall surface of the upstream side wall 511 . The protruding wall 71 is arranged in a region below the upstream chamber 51A and faces the intake air delivery opening 54 (FIG. 6) of the downstream chamber 51B in the front-rear direction. In relation to the drift rib 60 , the right edge of the projecting wall 71 is positioned slightly to the left of the rib main body 61 .

The projecting wall 71 has a rectangular shape elongated in the left-right direction in a plan view from the front side (FIG. 10). A portion of the protruding wall 71 protruding most forward is a substantially rectangular protruding plane substantially parallel to the upstream side surface 52A of the intercooler core 52 . As shown in FIGS. 7 and 9, the front end protruding plane of the protruding wall 71 is positioned further forward than the protruding end of the rib main body 61 described above. In this embodiment, the front-to-rear width of the space of the upstream chamber 51A is narrowed to about 1/2 to 1/3 of the other portions in the portion where the projecting wall 71 is arranged. The protrusion height of the projecting wall 71 can be selected depending on how much the ventilation resistance is to be increased, and the protrusion height may be smaller than that of the rib main body 61 . For example, the projecting height of the projecting wall 71 can be set within a range of 1/4 to 3/4 of the front-rear width of the upstream chamber 51A.

The flow rate adjusting portion 70 further includes a tapered wall 72 that is continuously provided above the projecting wall 71 . The tapered wall 72 is a wall extending upward so as to gradually widen the space in the front-rear direction of the upstream chamber 51A as it goes upward. That is, the lowermost end of the tapered wall 72 continues to the upper end portion 71A of the projecting wall 71, and the uppermost end of the tapered wall 72 continues near the upper end of the upstream side wall 511. As shown in FIG. An intermediate portion from the lowermost end to the uppermost end is an inclined surface that is inclined such that the height of the projection gradually decreases as it goes upward.

A right side wall 73, a left side wall 74, and a lower side wall 75 are connected to the right side, the left side, and the lower side of the projecting wall 71, respectively. The right side wall 73 , the left side wall 74 and the lower side wall 75 form a relatively steeply inclined surface, unlike the tapered wall 72 , which is not a gentle inclined surface. The right side wall 73 and left side wall 74 extend to the right and left of the tapered wall 72 . Between the drift rib 60 and the left side wall 74 of the tapered wall 72, there is provided a gap G having a predetermined width, which serves as a passage for directing the intake air upward.

By providing the drift rib 60 and the flow rate adjusting portion 70 as described above on the upstream side wall 511, the intake air can be distributed throughout the upstream chamber 51A, and the intake air can be evenly introduced from the entire surface of the upstream side surface 52A of the intercooler core 52. can. That is, part of the intake air flow entering from the intake air introducing portion 22</b>A is directed toward the intercooler core 52 by the drift ribs 60 . In addition, the remaining intake flow can be distributed throughout the space of the upstream chamber 51A on the left side of the drift rib 60 due to the airflow resistance adjustment effect of the flow rate adjusting portion 70 .

[Details of downstream side wall]
Next, the downstream side wall 514 that defines the space of the downstream chamber 51B will be described mainly with reference to FIGS. 6 and 7. FIG. As described above, in this embodiment, the expansion space 80 is provided above the downstream chamber 51B to expand the space of the downstream chamber 51B upward. The downstream side wall 514 has an expansion partition 514A that partitions the expansion space 80 .

The lateral width of the expansion space 80 is narrower than the lateral width of the downstream chamber 51B and slightly wider than the lateral width of the intake air delivery opening 54, as shown in FIG. Moreover, as shown in FIG. 7, the front-rear width of the expansion space 80 is slightly narrower than the front-rear width of the downstream chamber 51B. The height position where the expansion space 80 is formed is the same as the height position where the upper core holding portion 521 of the intercooler core 52 is arranged.

The expansion space 80 is partitioned by an expansion partition portion 514A, an upper wall extension portion 513A and a ceiling wall portion 513B. The extended partition portion 514A is a portion of the downstream side wall 514 located above the region facing the intercooler core 52 . The upper wall extension 513A is a wall that hangs downward from near the front end of the upper wall 513 . The ceiling wall portion 513B is a wall extending further forward from the front end of the upper wall 513 and is connected to the extended partition portion 514A. Due to the formation of the expansion space 80 , the space of the downstream chamber 51B expands above the lower end portion 523 of the upper core holding portion 521 .

Generally, unlike the intercooler core 52 that exchanges heat by allowing air to pass through, the upper core holding portion 521 does not have air permeability. Since the downstream chamber 51B provides a subsequent flow path for the intake air that has passed through the intercooler core 52, it is not necessary to expand the space of the downstream chamber 51B to the arrangement position of the upper core holding portion 521. However, in the present embodiment, the expansion space 80 is intentionally provided to expand the space of the downstream chamber 51B to a position corresponding to the upper core holding portion 521 . As a result, the ventilation resistance near the upper end of the downstream chamber 51B is reduced, and the intake air flow is facilitated to pass through the intercooler core 52 downstream and near the upper end.

As described above, the cavity of the storage recess 531 of the bottom lid member 53 expands the space of the downstream chamber 51B downward. As a result, airflow resistance near the lower end of the downstream chamber 51B is also reduced, making it easier for the intake air flow to pass through the vicinity of the lower end of the intercooler core 52 . Further, when molding the chamber 51 , the lower surface opening 55 that is eventually closed by the bottom cover member 53 can be used as a through-hole for a slide mold for molding the wall section that defines the expansion space 80 .

FIG. 11 is a cross-sectional view schematically showing the molding state of the expansion space 80. As shown in FIG. Since the expansion space 80 is an undercut-shaped part in the chamber 51, it is necessary to use a slide mold SC in addition to a normal molding mold for molding the expansion partition portion 514A that defines the expansion space 80. . The opening 55 on the lower surface, which is positioned to face the expansion space 80 vertically, is suitable for inserting and removing the slide mold SC. Accordingly, the provision of the bottom opening 55 facilitates molding of the chamber 51, including the extended section 514A. In addition, by covering the lower surface opening 55 with the bottom cover member 53, the sealing of the chamber 51 can be ensured.

The downstream side wall 514 includes a main wall surface 5141 and side wall surfaces 5142 that are continuously provided on both left and right sides of the main wall surface 5141 . The main wall surface 5141 is located in the central region of the downstream side wall 514 in the left-right direction, has an extended partition 514A at its upper end, and has an upper edge 541 at its lower end for partitioning the intake air delivery opening 54. ing. As is clear from FIG. 7, the main wall surface 5141 defines the space of the downstream chamber 51B such that the distance from the downstream side surface 52B of the intercooler core 52 increases downward. On the other hand, the side wall surface 5142 is a wall surface extending downward substantially parallel to the downstream side surface 52B.

The main wall surface 5141 and the side wall surface 5142 form a shallow and wide guide groove extending vertically in the downstream side wall 514 . This guide groove contributes to reducing ventilation resistance when the intake air that has passed through the upper region of the intercooler core 52 is directed toward the intake air delivery opening 54 . Therefore, the intake air can be smoothly delivered from the entire area of the intercooler core 52 to the downstream side intake passage 24 .

[Intake behavior]
FIG. 12 is an enlarged view of the main part of FIG. 5 and shows the intake air flow Fw passing through the intercooler 23. As shown in FIG. Intake air taken into the intake unit 40 enters the upstream chamber 51A of the chamber 51 from the intake air introducing portion 22A of the upstream intake passage 22 . The upstream chamber 51A is a space extending over the entire length of the intercooler core 52 in terms of vertical width and horizontal width. Further, in the present embodiment, a nonuniform flow rib 60 and a flow rate adjusting section 70 are provided to disperse the intake air throughout the upstream chamber 51A. Therefore, the intake air flow Fw passes through the entire upper, lower, left and right sides of the intercooler core 52 and reaches the downstream chamber 51B. During this passage, the intake air flow Fw exchanges heat with the cooling fins of the intercooler core 52 and is cooled.

The route from the downstream chamber 51B to the downstream side intake passage 24 is limited to the route passing through the intake air delivery opening 54 . The intake air delivery opening 54 is then arranged in the lower end region of the chamber 51 . Therefore, the intake air flow Fw that has entered the downstream chamber 51B from the intercooler core 52 gathers toward the intake air delivery opening 54 and becomes a unified flow. This prevents the intake flow that has passed through the intercooler core 52 from randomly flowing into the downstream intake passage 24 . After passing through the intake air delivery opening 54 , the intake air flow Fw enters the downstream intake passage 24 . That is, the intake flow Fw enters an extension passage portion 242 that curves upward and extends from an upstream end 241 connected to the intake air delivery opening 54 . It should be noted that such an intake flow Fw is exclusively formed as the cylinder 2 is made to have a negative pressure by executing the combustion operation in the cylinder 2 .

After exiting the intake air delivery opening 54, the intake air flow Fw forms a main flow accompanied by swirl of the secondary flow and proceeds upward through the downstream intake passage 24 (extending passage portion 242). EGR gas is introduced from the pair of left and right EGR introduction ports 45 and blow-by gas is introduced from the blow-by introduction port 163 into the extension passage portion 242 . These EGR gas and blow-by gas hit the main flow of the intake air flow Fw, are mixed with the intake air, and flow toward the engine main body 1 .

FIG. 13 is a schematic diagram for explaining the flow of intake air within the chamber 51P according to the comparative example. Unlike the present embodiment, this chamber 51P does not have an expansion space 80 that expands the space of the downstream chamber 51B upward. The intake flow F0 introduced into the intake unit 40 from the inlet 220 enters the upstream chamber 51A through the intake introduction portion 22A (the downstream portion of the upstream intake passage 22). After that, the intake flow F0 passes through the intercooler core 52 and becomes an intake flow F11 reaching the downstream chamber 51B. Then, an intake flow F12 is formed, which flows from the downstream chamber 51B through the intake air delivery opening 54 disposed at the lower end of the chamber 51P and ascends the extension passage portion 242 of the downstream side intake passage 24 .

Here, since the vicinity of the upper end of the downstream chamber 51B does not have the expansion space 80, there is no space for the intake flow to escape upward, resulting in a region with relatively high ventilation resistance. That is, even if the downstream chamber 51B has a space up to a region corresponding to the upper end of the main body of the intercooler core 52, if the upper end is immediately partitioned by a wall, it becomes difficult for intake air to flow in the vicinity of the upper end. end up Moreover, in this embodiment, the intake air delivery opening 54, which serves as an outlet for the intake air from the chamber 51P, is arranged at the lower end of the chamber 51P. Therefore, the intake airflow F11 naturally becomes a flow directed downward. In other words, an intake flow F11 that flows in a short-circuit from near the upper end of the upstream chamber 51A toward the lower end of the downstream chamber 51B tends to be formed. Therefore, the downstream side (front side) and upper region of the intercooler core 52 is in a state in which it is difficult for the intake air to pass through.

FIG. 14 is a schematic diagram for explaining the flow of intake air in chamber 5101 according to a modification of this embodiment. This chamber 5101 has an expansion space 80 that expands the space of the downstream chamber 51B upward, as in the present embodiment. However, the bottom cover member 53 that expands the space of the downstream chamber 51B downward is not provided.

The intake flow F0 introduced into the intake unit 40 through the inlet 220 enters the upstream chamber 51A and then becomes the intake flow F21 passing through the intercooler core 52 . Since the expansion space 80 exists in the vicinity of the upper end of the downstream chamber 51B, there exists a space for the intake flow to escape upward. Therefore, the vicinity of the upper end of the downstream chamber 51B becomes a region with lower airflow resistance than in the comparative example of FIG. 13, and an intake airflow passing through the vicinity of the upper end is easily generated. Due to such factors, the intake air flow F21 passes through the downstream side (front side) and upper region of the intercooler core 52, reaches the vicinity of the upper end of the downstream chamber 51B, and forms a flow toward the intake air delivery opening . Since a flow like this intake air flow F21 is formed, the dispersion of intake air in the intercooler core 52 can be enhanced. After that, an intake flow F22 is formed that passes through the intake air delivery opening 54 and rises through the extension passage portion 242 . The extension passage portion 242 is a relatively long passage utilizing the vertical length of the downstream side wall 514 . Therefore, it becomes easy to secure a sufficient intake passage length downstream of the intercooler 23, and the intake flow can be guided to the engine main body 1 in a rectified state.

FIG. 15 is a schematic diagram for explaining the flow of intake air in the chamber 51 according to this embodiment. As described in the present embodiment, the chamber 51 includes an expansion space 80 that expands the space of the downstream chamber 51B upward, and a bottom lid that has a storage recess 531 (cavity) that expands the space of the downstream chamber 51B downward. A member 53 is provided. In this aspect, the expansion space 80 reduces ventilation resistance in the vicinity of the upper end of the downstream chamber 51B, and the storage recess 531 reduces ventilation resistance in the vicinity of the lower end.

The intake air flow F21 passing through the upper region of the intercooler core 52 reaches the vicinity of the upper end of the downstream chamber 51B via the downstream and upper region of the intercooler core 52 due to the ventilation resistance reduction effect of the expansion space 80 provided. After that, an intake flow F22 is formed that passes through the intake air delivery opening 54 and rises through the extension passage portion 242 . These points are the same as the modified embodiment of FIG.

Furthermore, in the present embodiment, the intake flow F23 that passes through the lower region of the intercooler core 52 and smoothly flows toward the intake air delivery opening 54 is easily formed. That is, if the lower end of the downstream chamber 51B is partitioned at a position corresponding to the lower end of the intercooler core 52, there will be no space near the lower end for the intake flow to escape downward. This somewhat increases the intake resistance in the vicinity of the lower end of the downstream chamber 51B, making it difficult for the intake air to flow. However, in the present embodiment, since the reservoir recess 531 exists, the intake resistance can be suppressed, and a flow such as the intake flow F23 can be easily formed. That is, an intake air flow can be formed that passes through the upstream (rear) and lower regions of the intercooler core 52 and reaches the vicinity of the lower end of the downstream chamber 51B.

In addition, an intake flow F24 that flows into the reservoir recess 531 of the bottom lid member 53 is also formed. Condensed water W of moisture contained in the EGR gas and the blow-by gas introduced into the extension passage portion 242 is stored in the storage recess 531 . The intake flow F24 becomes a flow in contact with the water surface of the stored condensed water W, and serves to carry out an appropriate amount of water. Therefore, the cavity of the storage recess 531 does not substantially disappear due to the storage of the condensed water W.

[Modification]
Although the embodiment of the present invention has been described above, the present invention is not limited to this, and for example, the following modified embodiments can be adopted.

(1) In the above-described embodiment, as shown in FIG. 6, the expansion space 80 has a lateral width substantially the same as the lateral width of the main wall surface 5141 of the downstream side wall 514 . Alternatively, the expansion space 80 may have a lateral width substantially the same as the lateral width of the downstream side wall 514 . Also, in the side view in the front-rear direction, the rectangular expansion space 80 elongated in the left-right direction was exemplified, but the expansion space 80 may be trapezoidal, triangular, or dome-shaped, for example.

(2) In the above-described embodiment, the downstream side wall 514 has the main wall surface 5141 whose distance from the downstream side surface 52B of the intercooler core 52 increases downward. The main wall surface 5141 may be a wall surface having a constant interval in the front-rear direction with respect to the downstream side surface 52B. Further, the downstream side wall 514 may be a flat surface in which unevenness between the main wall surface 5141 and the side wall surface 5142 does not exist.

(3) In the above embodiment, an example in which the intake system according to the present invention is applied to a multi-cylinder turbocharged gasoline engine was shown. The intake device according to the present invention can also be applied to diesel engines, and can also be applied to engines that do not have the turbocharger 15 .

Reference Signs List 1 engine main body 20 intake passage 22 upstream intake passage 22A intake introduction portion 23 intercooler 24 downstream intake passage 242 extension passage portion 51 chamber 51A upstream chamber 51A
51B downstream chamber 51B
511 upstream side wall 514 downstream side wall 514A expansion partition 52 intercooler core 521 upper core holding portion (core holding portion)
523 lower end portion 53 bottom lid member (lid member)
531 storage recess (cavity)
54 inspiratory delivery opening 80 expansion space

Claims (6)

an intercooler including a chamber and an intercooler core housed inside the chamber;
an intake passage including a downstream side intake passage located downstream of the chamber and guiding intake air to the engine body through the intercooler core in the chamber;
The chamber includes a downstream chamber that is a space adjacent to the downstream side of the intercooler core and communicates with the downstream intake passage, a downstream side wall that faces the downstream side and partitions the space of the downstream chamber, and the intercooler. a core holder that holds the upper end face of the core,
The downstream sidewall is
an intake air delivery opening disposed near the lower end thereof for delivering intake air having passed through the intercooler core to the downstream intake passage;
an expansion partition section that partitions an expansion space that expands the space of the downstream chamber above the lower end of the core holding section. In the engine intake device according to claim 1,
An intake system for an engine, wherein the downstream intake passageway includes an extending passageway portion extending upward along the downstream sidewall of the chamber. 3. In the engine intake device according to claim 1 or 2,
The intake device of the engine, wherein the downstream side wall divides the space of the downstream chamber such that the distance from the downstream side of the intercooler core widens downward. In the engine intake device according to any one of claims 1 to 3,
The chamber has a bottom wall located below the intercooler core,
The intake device for an engine, wherein the bottom wall includes a bottom opening that opens at a position corresponding to the downstream chamber, and a cover member that closes the bottom opening. In the engine intake device according to claim 4,
The air intake device for an engine, wherein the cover member has a cavity that expands the space of the downstream chamber downward. In the engine intake device according to any one of claims 1 to 5,
The chamber is
the intake passage further includes an upstream intake passage positioned upstream from the chamber;
the upstream intake passage has an intake introduction portion that guides intake air into the chamber;
The air intake device for an engine, wherein the intake air introducing portion is arranged to face an upper region of the intercooler core.

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