WO2019073555A1 - Engine with supercharger - Google Patents

Abstract

The supercharger 34 and the core 36a of the intercooler 36 are juxtaposed in the vertical direction, and the supercharger 34 and the core 36a are disposed via relay passages disposed on the front side in the longitudinal direction of each vehicle. Connected to each other. The downstream end of the relay passage 80 is constituted by the introduction portion 36d of the intercooler 36, and is directed toward the core 36a in the longitudinal direction of the vehicle as it goes from the turbocharger 34 to the core 36a in the vertical direction. It extends obliquely.

Description

Supercharged engine

The technology disclosed herein relates to a supercharged engine.

Patent Document 1 discloses an example of a supercharged engine. Specifically, the engine disclosed in Patent Document 1 includes an intake passage (common intake passage) connected to a combustion chamber, and a turbocharger (compressor of an exhaust turbocharger) disposed in the intake passage. And a heat exchanger (intercooler) disposed downstream of the turbocharger in the intake passage.

JP, 2009-41386, A

By the way, the heat exchange device as described in Patent Document 1 usually accommodates a heat exchange portion (so-called core) for exchanging heat with the gas that has passed through the turbocharger.

In recent years, from the viewpoint of downsizing of the engine, the turbocharger and the heat exchange unit as described above may be juxtaposed along a predetermined direction (for example, the vertical direction). In this case, the supercharger and the heat exchange unit are mutually connected via a relay passage disposed on one side of each (for example, the front side in the vehicle longitudinal direction).

However, when such a relay passage is provided, the pulsation generated in the discharge pressure of the turbocharger acts on the wall surface of the relay passage, which may cause a radiation noise. Therefore, there is room for improvement in improving the quietness of the engine.

The technique disclosed herein has been made in view of the above point, and its purpose is to improve quietness of a supercharged engine while achieving compactness of the engine.

The technology disclosed herein includes an intake passage connected to a combustion chamber, a supercharger disposed in the intake passage, and a downstream of the supercharger disposed in the intake passage. And a heat exchange device configured to receive a heat exchange unit configured to exchange heat with a gas that has passed through the machine.

The supercharger and the heat exchange unit are juxtaposed along a predetermined first direction, and when the direction orthogonal to the first direction is referred to as a second direction, the supercharged engine may It further comprises a relay passage disposed on one side in the second direction with respect to the supercharger and the heat exchange part, and configured to mutually connect the supercharger and the heat exchange part.

The downstream end of the relay passage extends along the side surface on one side in the second direction in the heat exchange unit, and the downstream end (the downstream end of the relay passage) is the first end. It extends gradually in the second direction toward the heat exchange portion side as it goes from the turbocharger side to the heat exchange portion side in the direction.

Here, the heat exchange device may be a so-called intercooler or an interwarmer.

According to the above configuration, the turbocharger and the heat exchange unit are aligned along the first direction. And a supercharger and a heat exchange part are mutually connected via the relay passage arrange | positioned at each 2nd direction one side. This makes it possible to integrate the supercharger and the heat exchange device, and in turn make the engine compact.

On the other hand, the downstream end of the relay passage extends gradually in the second direction toward the heat exchange portion as it goes from the turbocharger side to the heat exchange portion in the first direction.

That is, the downstream end of the relay passage extends straight from the supercharger side to the heat exchange portion side along the first direction and then is not bent to the heat exchange portion side along the second direction. , And obliquely extending in both the first direction and the second direction.

Such an oblique extension reduces the surface area of the relay passage (in particular, the inner wall of the relay passage).

It is considered that the above-mentioned radiation noise is generated when the relay passage vibrates due to the pulsation of the supercharger, and the volume of the radiation sound can be suppressed by reducing the surface area of the relay passage as described above. It will be possible. Thus, the quietness of the engine can be enhanced.

Further, the relay passage includes: a duct portion connected to a gas discharge portion in the turbocharger; and a gas introduction portion in the heat exchange device connected to the discharge portion via the duct portion The downstream end of the relay passage may include the introduction portion.

According to this configuration, by devising the shape of the gas introduction part in the heat exchange device, the introduction part can be used as the above-described downstream end.

Further, the heat exchange device has a housing configured to accommodate the heat exchange portion, and the introduction portion extends from the housing toward the supercharger, and the supercharger side The duct portion may be connected to one end of

According to this configuration, the duct portion can be configured to be short because the introductory portion is extended toward the turbocharger side. The duct portion is a portion directly connected to the discharge portion of the supercharger, and there is a concern about the generation of the radiation noise as it is close to the discharge portion. By shortening the duct portion, it is possible to suppress the volume of the radiated noise and to improve the quietness of the engine.

Further, of the inner wall of the duct portion, the inner wall portion facing the discharge portion is curved to form a convex toward the opposite side of the turbocharger when viewed in a cross section perpendicular to the first direction. May have a curved portion.

According to the above configuration, by providing the curved portion as described above, it is possible to prevent concentration of stress on a local part of the duct portion. This is advantageous in increasing the rigidity of the duct portion and thus suppressing the volume of the radiated sound. This can improve the quietness of the engine.

Further, the discharge portion may be inclined and opened toward the heat exchange device in the first direction.

According to this configuration, since the discharge portion of the turbocharger is inclined toward the heat exchange device, it is advantageous in shortening the passage length from the discharge portion to the introduction portion of the heat exchange device. This is effective in enhancing the quietness of the engine.

Further, the supercharger-equipped engine includes an engine body having a cylinder head and a cylinder block, and a radiator disposed on one side of the second direction with respect to the engine body, and the heat exchange device includes: The downstream end of the relay passage is disposed between the engine main body and the radiator in the second direction, and the downstream end of the relay passage is viewed in a cross section in a plane including the first direction and the second direction. It may be formed to be concave toward the radiator.

According to this configuration, the downstream end of the relay passage is formed, for example, to be convex toward the radiator in the second direction, or to be flat compared to the case without convex. , Will be separated from the radiator. As a result, the distance between the downstream end and the radiator can be more sufficiently secured.

This configuration is particularly effective in that interference with the heat exchange device and the radiator can be more reliably suppressed when the downstream end of the relay passage is configured by the introduction portion of the heat exchange device. .

Another technique disclosed herein relates to an intake passage connected to a combustion chamber, a turbocharger disposed in the intake passage, and heat exchange disposed downstream of the turbocharger in the intake passage. A heat exchange unit configured to exchange heat with the gas that has passed through the turbocharger, and a housing configured to accommodate the heat exchange unit. And a supercharged engine having

The supercharger and the heat exchange unit are juxtaposed along a predetermined first direction, and when the direction orthogonal to the first direction is referred to as a second direction, the supercharged engine may It further comprises a relay passage disposed on one side in the second direction with respect to the supercharger and the heat exchange part, and configured to mutually connect the supercharger and the heat exchange part.

The relay passage has a duct portion connected to a gas discharge portion of the turbocharger, and a gas introduction portion of the heat exchange device connected to the discharge portion via the duct portion.

The introduction portion extends from the housing toward the supercharger in the first direction, and the duct portion is connected to one end of the introduction portion on the supercharger side.

According to this configuration, the quietness of the engine can be enhanced while the engine can be made compact.

As described above, according to the above-described supercharged engine, the quietness can be enhanced while achieving the downsizing of the engine.

FIG. 1 is a schematic view illustrating the configuration of an engine. FIG. 2 is a front view of the engine. FIG. 3 is a view of the engine as viewed from above. FIG. 4 is a diagram showing the flow of gas in the intake passage at the time of supercharging and at the time of natural intake. FIG. 5 is a diagram showing the intake passage as viewed obliquely from the front side. FIG. 6 is a view showing the intake passage from the front side. FIG. 7 is a longitudinal sectional view of the intake passage. FIG. 8 is a longitudinal sectional view of the intake passage. FIG. 9 is a cross-sectional view of the intake passage. FIG. 10 is a diagram showing the relative positional relationship between the intake passage and the radiator. FIG. 11 is a view showing the intake passage from the rear side. FIG. 12 is a view showing the intake passage from the upper side.

Hereinafter, an embodiment of a supercharged engine will be described in detail based on the drawings. The following description is an example. FIG. 1 is a schematic view illustrating the configuration of a supercharged engine (hereinafter simply referred to as “engine”) 1 disclosed herein. 2 is a view showing the engine 1 as viewed from the front, and FIG. 3 is a view showing the engine 1 as viewed from the upper side.

The engine 1 is a four-stroke type internal combustion engine mounted in a car, and as shown in FIGS. 1 to 3, it is configured to have a mechanical type supercharger 34 operated by power transmitted from the outside. ing. The fuel of the engine 1 is gasoline in this configuration example.

Further, although the engine 1 is not shown in detail, it has four cylinders (cylinders) 11 arranged in a row, and the four cylinders 11 are mounted in a line along the vehicle width direction. It is configured as a so-called in-line four-cylinder horizontal engine. Thereby, in this configuration example, the engine longitudinal direction which is the arrangement direction (cylinder row direction) of four cylinders 11 substantially coincides with the vehicle width direction, and the engine widthwise direction substantially coincides with the vehicle longitudinal direction There is.

In the in-line multi-cylinder engine, the cylinder row direction coincides with the central axis direction (engine output shaft direction) of the crankshaft 15 as the engine output shaft. In the following description, these directions may be collectively referred to as the cylinder row direction (or the vehicle width direction).

Hereinafter, unless otherwise specified, the front side refers to the front side in the vehicle longitudinal direction, the rear side refers to the rear side in the vehicle longitudinal direction, and the left side is one side in the vehicle width direction (one side in the cylinder row direction, The right side refers to the other side in the vehicle width direction (the other side in the cylinder row direction, that is, the engine front side).

Further, in the following description, the upper side refers to the upper side in the vehicle height direction in a state where the engine 1 is mounted on a vehicle (hereinafter, also referred to as "vehicle mounting state"), and the lower side is the vehicle height direction in the vehicle mounted state Point down.

The vehicle height direction is an example of the “first direction”, and the vehicle longitudinal direction is an example of the “second direction”.

(Schematic configuration of engine)
In this configuration example, the engine 1 is configured in a front intake / rear exhaust system. That is, the engine 1 includes an engine body 10 having four cylinders 11, an intake passage 30 disposed on the front side of the engine body 10 and communicating with each cylinder 11 via the intake port 18, and a rear side of the engine body 10 And an exhaust passage 50 communicating with each cylinder 11 through the exhaust port 19.

In this configuration example, the intake passage 30 includes a plurality of passages for introducing gas, devices such as the supercharger 34 and the intercooler 36, and an air bypass passage (hereinafter referred to simply as “passage to the combustion chamber 16”) bypassing these devices. A “bypass passage” 40) is combined to constitute a unitized intake system.

The engine body 10 is configured to burn a mixture of gas and fuel supplied from the intake passage 30 in each cylinder 11 according to a predetermined combustion order. Specifically, the engine body 10 has a cylinder block 12 and a cylinder head 13 mounted thereon.

The aforementioned four cylinders 11 are formed inside the cylinder block 12. The four cylinders 11 are arranged in a row along the central axis direction of the crankshaft 15 (that is, the cylinder row direction). In FIG. 1, only one cylinder is shown.

A piston 14 is slidably inserted into each cylinder 11. The piston 14 is connected to the crankshaft 15 via a connecting rod 141. The piston 14 defines the combustion chamber 16 together with the cylinder 11 and the cylinder head 13. The “combustion chamber” referred to here is not limited to the meaning of the space formed when the piston 14 reaches the compression top dead center. The term "combustion chamber" is used in a broad sense.

In the cylinder head 13, two intake ports 18 are formed for one cylinder 11. Only one intake port 18 is shown in FIG. The two intake ports 18 are adjacent in the cylinder row direction, and communicate with the corresponding cylinders 11 respectively.

An intake valve 21 is disposed in each of the two intake ports 18. The intake valve 21 opens and closes between the combustion chamber 16 and each intake port 18. The intake valve 21 is opened and closed at a predetermined timing by an intake valve mechanism.

In this configuration example, as shown in FIG. 1, the intake valve operating mechanism has an intake electric motor S-VT (Sequential-Valve Timing) 23 which is a variable valve operating mechanism. The intake electric motor S-VT 23 is configured to continuously change the rotational phase of the intake camshaft within a predetermined angular range. As a result, the opening timing and closing timing of the intake valve 21 change continuously. The intake valve operating mechanism may have a hydraulic S-VT instead of the intake electric motor S-VT 23.

The cylinder head 13 is also provided with two exhaust ports 19 per cylinder 11. Only one exhaust port 19 is illustrated in FIG. The two exhaust ports 19 are adjacent in the cylinder row direction and communicate with the corresponding cylinders 11 respectively.

Exhaust valves 22 are disposed at the two exhaust ports 19 respectively. The exhaust valve 22 opens and closes between the combustion chamber 16 and each exhaust port 19. The exhaust valve 22 is opened and closed at a predetermined timing by an exhaust valve mechanism.

As shown in FIG. 1, the exhaust valve mechanism has an exhaust motor S-VT (Sequential-Valve Timing) 24 which is a variable valve mechanism in this configuration example. The exhaust motor S-VT 24 is configured to continuously change the rotational phase of the exhaust camshaft within a predetermined angular range. Thereby, the valve opening timing and the valve closing timing of the exhaust valve 22 change continuously. The exhaust valve mechanism may have a hydraulic S-VT instead of the exhaust motor S-VT 24.

An injector 6 is attached to the cylinder head 13 for each cylinder 11. The injector 6 is a multi-injection-type fuel injection valve in this configuration example, and is configured to inject fuel directly into the combustion chamber 16.

A fuel supply system 61 is connected to the injector 6. The fuel supply system 61 includes a fuel tank (not shown) configured to store fuel, and a fuel supply passage 62 connecting the fuel tank and the injector 6 to each other. A fuel pump 65 and a common rail 64 are interposed in the fuel supply passage 62.

A spark plug 25 is attached to the cylinder head 13 for each cylinder 11. The spark plug 25 is attached in such a posture that the tip thereof faces the combustion chamber 16 and forcibly ignites the mixture in the combustion chamber 16.

Returning to the explanation of the intake passage 30, the intake passage 30 in this configuration example is connected to one side surface (specifically, the front side surface) of the engine body 10, and communicates with the intake port 18 of each cylinder 11. ing. That is, the intake passage 30 is a passage through which the gas introduced into the combustion chamber 16 flows, and is connected to the combustion chamber 16 via each intake port 18.

Here, an air cleaner 31 for filtering fresh air is disposed at the upstream end of the intake passage 30. On the other hand, a surge tank 38 is disposed near the downstream end of the intake passage 30. The intake passage 30 downstream of the surge tank 38 constitutes an independent passage 39 branched by two for each cylinder 11. The downstream end of the independent passage 39 is connected to the intake port 18 of each cylinder 11.

A throttle valve 32 is disposed between the air cleaner 31 and the surge tank 38 in the intake passage 30. The throttle valve 32 is configured to adjust the amount of fresh air introduced into the combustion chamber 16 by adjusting the degree of opening thereof.

A supercharger 34 is disposed downstream of the throttle valve 32 in the intake passage 30. The supercharger 34 is configured to supercharge the gas introduced into the combustion chamber 16. In this configuration example, the supercharger 34 is a mechanical supercharger driven by the engine 1 (specifically, power transmitted from the crankshaft 15). The supercharger 34 is configured as a two-axis rotor type roots blower.

An electromagnetic clutch 34 a is interposed between the turbocharger 34 and the crankshaft 15. The electromagnetic clutch 34 a transmits the driving force between the turbocharger 34 and the crankshaft 15 and cuts off the transmission of the driving force. As will be described later, the control device (not shown), such as an ECU (Engine Control Unit), switches on and off of the electromagnetic clutch 34a to switch on and off the supercharger 34. That is, the engine 1 switches between the operation of supercharging the gas introduced into the combustion chamber 16 and the operation of not supercharging the gas introduced into the combustion chamber 16 by switching the supercharger 34 on and off. It is configured to be able to

An intercooler 36 is disposed downstream of the turbocharger 34 in the intake passage 30. The intercooler 36 comprises a core 36a (see also FIG. 9) configured to exchange heat with the gas that has passed through the turbocharger 34, and the compressed gas is It is configured to cool. The intercooler 36 in this configuration example is water cooled. The intercooler 36 is an example of the "heat exchange device", and the core 36a is an example of the "heat exchange unit".

Further, as a passage connecting various devices incorporated in the intake passage 30, the intake passage 30 is disposed downstream of the air cleaner 31 and is a first passage for guiding the gas purified by the air cleaner 31 to the turbocharger 34. 33, a second passage 35 for guiding the gas compressed by the turbocharger 34 to the intercooler 36, and a third passage 37 for guiding the gas cooled by the intercooler 36 to the surge tank 38.

Although described in detail later, the second passage 35 exemplifies the “duct portion” in that it is connected to the gas discharge portion 34 c of the turbocharger 34, and the gas introduction portion 36 d of the intercooler 36. Together with the relay passage 80.

Further, in the intake passage 30, the first passage 33, the second passage 35, the third passage 37, and the surge tank 38 are provided with the supercharger 34 and the intercooler 36 sequentially from the upstream side along the gas flow direction. Constitute the "main intake passage". Hereinafter, the main intake passage is denoted by the symbol "30A".

Further, the intake passage 30 is provided with a bypass passage 40 bypassing the turbocharger 34 and the intercooler 36 separately from the above-described main intake passage 30A. Specifically, the bypass passage 40 branches from the upstream side of the turbocharger 34 in the main intake passage 30A and is connected to the downstream side of the intercooler 36 (specifically, the surge tank 38).

Further, in the bypass passage 40, an air bypass valve (hereinafter simply referred to as a "bypass valve") 41 for changing the flow passage cross-sectional area of the bypass passage 40 is disposed. The bypass valve 41 adjusts the flow rate of gas flowing through the bypass passage 40 by changing the flow passage cross-sectional area of the bypass passage 40.

FIG. 4 shows the flow of gas in the intake passage 30 at the time of supercharging and at the time of natural intake.

When the supercharger 34 is turned off (that is, when the electromagnetic clutch 34a is disconnected), the bypass valve 41 is fully opened. Thus, the gas flowing through the intake passage 30 bypasses the turbocharger 34 and flows into the surge tank 38 as shown in the lower part of FIG. 4 and is introduced into the combustion chamber 16 via the independent passage 39. The engine 1 operates with non-supercharging, that is, natural intake.

When the supercharger 34 is turned on (that is, when the electromagnetic clutch 34a is connected), the opening degree of the bypass valve 41 is appropriately adjusted. As a result, a part of the gas that has passed through the turbocharger 34 in the intake passage 30 flows back through the bypass passage 40 upstream of the turbocharger 34 as shown in the upper view of FIG. 4. Since the reverse flow rate can be adjusted by adjusting the opening degree of the bypass valve 41, the supercharging pressure of the gas introduced into the combustion chamber 16 can be adjusted via the reverse flow rate. In this configuration example, a supercharging system is configured by the supercharger 34, the bypass passage 40, and the bypass valve 41.

On the other hand, the exhaust passage 50 is connected to the other side surface (specifically, the rear side surface) of the engine body 10 and communicates with the exhaust port 19 of each cylinder 11. The exhaust passage 50 is a passage through which the exhaust gas discharged from the combustion chamber 16 flows. Although not shown in detail, the upstream portion of the exhaust passage 50 constitutes an independent passage which branches off for each cylinder 11. The upstream ends of the independent passages are connected to the exhaust port 19 of each cylinder 11.

An exhaust gas purification system having one or more catalytic converters 51 is disposed in the exhaust passage 50. The catalytic converter 51 is configured to include a three-way catalyst. The exhaust gas purification system is not limited to one including only the three-way catalyst.

An EGR passage 52 constituting an external EGR system is connected between the intake passage 30 and the exhaust passage 50. The EGR passage 52 is a passage for recirculating a part of the burned gas to the intake passage 30. Specifically, the upstream end of the EGR passage 52 is connected to the downstream of the catalytic converter 51 in the exhaust passage 50. On the other hand, the downstream end of the EGR passage 52 is connected to the upstream of the turbocharger 34 and the downstream of the throttle valve 32 in the intake passage 30.

A water-cooled EGR cooler 53 is disposed in the EGR passage 52. The EGR cooler 53 is configured to cool the burned gas. The flow rate of the burned gas flowing through the EGR passage 52 is adjusted by the EGR valve 54. Although the EGR valve 54 is illustrated as being disposed on the EGR passage 52 on the paper surface of FIG. 1, in an actual configuration, it is disposed on the bypass passage 40 as shown in FIG. There is. By adjusting the opening degree of the EGR valve 54, it is possible to adjust the reflux amount of the cooled burned gas, that is, the external EGR gas.

In this configuration example, the EGR system 55 includes an external EGR system configured to include the EGR passage 52 and the EGR valve 54, and an interior configured to include the intake electric motor S-VT 23 and the exhaust motor S-VT 24 described above. And an EGR system.

In addition to the above-described fuel pump 65, various accessories are attached to the engine 1 as well. The engine 1 is provided with an alternator 91 for generating an alternating current used in the electric system, an air conditioner 92 for air conditioning, and a water pump (not shown) for circulating cooling water as such auxiliary equipment. .

As shown in FIG. 2, the fuel pump 65 is attached to the front surface (outer surface) on the left end side of the engine body 10. On the other hand, the alternator 91 and the air conditioner 92 are attached to the front end on the right end side of the engine body 10. The alternator 91 and the air conditioner 92 are arranged in this order from above. Further, above the alternator 91, a drive pulley 34d of the turbocharger 34 is disposed. Although not described in detail, a drive belt 81 for driving the supercharger 34 is wound around the drive pulley 34d.

The engine 1 also includes a radiator 93 for heat exchange with the coolant (see FIG. 10). Although details will be described later, the radiator 93 is disposed in front of the engine main body 10 in the vehicle longitudinal direction.

(Configuration of intake passage)
Hereinafter, the configuration of the main part of the intake passage 30 will be described in detail.

FIG. 5 is a view showing the intake passage 30 as viewed obliquely from the front side. FIG. 6 is a view showing the intake passage 30 as viewed from the front side. FIG. 7 is a longitudinal sectional view of the intake passage 30. As shown in FIG. FIG. 8 is also a longitudinal sectional view of the intake passage 30. FIG. 9 is a cross-sectional view of the intake passage 30. FIG. 10 is a view showing a relative positional relationship between the intake passage 30 and the radiator 93. As shown in FIG. FIG. 11 is a view showing the intake passage 30 from the rear side. FIG. 12 is a view showing the intake passage 30 from the upper side.

Each component constituting the intake passage 30 is disposed along the front side of the engine body 10, specifically, along the front surfaces of the cylinder head 13 and the cylinder block 12.

In addition, as described above, the intake passage 30 includes a plurality of passages (specifically, the first passage 33, the second passage 35, the third passage 37, the surge tank 38, and the independent passage 39) for introducing gas. Devices such as the feeder 34 and the intercooler 36 and a bypass passage 40 bypassing these devices are combined. As shown in FIG. 5 and the like, the main intake passage 30A constituting the intake passage 30 is disposed below the bypass passage 40.

In the engine 1, a supercharger 34 and an intercooler 36 are integrated and disposed in the vicinity of the upstream end of the intake port 18 in order to enhance the supercharging response.

Then, if the schematic layout of these components is explained, as shown in FIG. 2 etc., the supercharger 34 is disposed opposite to the opposite side of the engine main body 10 with the surge tank 38 interposed therebetween. . A gap corresponding to the size of the surge tank 38 is open between the rear surface of the turbocharger 34 and the front surface of the engine body 10. The first passage 33 extends in the cylinder row direction on the left end side of the turbocharger 34 and is connected to the left end of the turbocharger 34. Moreover, the supercharger 34 and the intercooler (specifically, the core 36a of the intercooler 36) 36 are juxtaposed in this order along the vertical direction, and are adjacent in the same direction. Further, a gas discharge part 34c of the turbocharger 34, a second passage 35, and a gas introduction part 36d of the intercooler 36 are disposed on the front side of each of the turbocharger 34 and the core 36a. The second passage 35 extends substantially in the vertical direction so as to mutually connect the discharge portion 34c and the introduction portion 36d. The surge tank 38 is disposed between the turbocharger 34 and the engine body 10, and is disposed opposite to the upstream end of the intake port 18 across the plurality of independent passages 39. There is. The third passage 37 extends so as to sew a gap between the intercooler 36 and the supercharger 34 and the engine main body 10 so that the intercooler 36 is located below the surge tank 38, The rear of the intercooler 36 and the bottom of the surge tank 38 are connected. The bypass passage 40 is branched from the middle of the first passage 33 and extends upward, and then is formed to extend inward (rightward) of the engine body 10, and is branched into two at the downstream side It is connected to the top of the surge tank 38 at the top.

Thus, the engine 1 arranges the supercharger 34 and the intercooler 36 up and down, and connects the supercharger 34 and the intercooler 36 to each other by the second passage 35 disposed on the front side of each. ing. With such a layout, for example, as shown in FIG. 2, an alternator 91 disposed on the right side in the cylinder row direction, auxiliary equipment such as an air conditioner 92, an EGR valve 54 disposed on the left side in the same direction, The turbocharger 34 and the intercooler 36 can be disposed in the vicinity of the upstream end of the intake port 18 without causing interference with valve members such as the bypass valve 41 and the throttle valve 32. This is effective in making the engine 1 compact.

Hereinafter, in order to describe in detail the layout related to the downsizing of the engine 1, the structure of each part constituting the intake passage 30 will be sequentially described.

The first passage 33 is provided with the throttle valve 32, and is configured to extend from one side to the other side (specifically, from the left side to the right side) in the cylinder row direction. Specifically, as shown in FIG. 7 to FIG. 8 etc., the first passage 33 is formed in a tubular shape extending in the cylinder row direction (left and right direction), and the upstream portion (left side) portion thereof Is constituted by a throttle body 33a in which is incorporated. The throttle body 33a is formed in a metal short cylinder shape, and is disposed so as to be located leftward and forward with respect to the front surface of the engine body 10, with the openings at both ends directed to the left and right. The air cleaner 31 is connected to the upstream end (left end) of the throttle body 33a via a passage (not shown), while the upstream end (left side) of the first passage 33 is connected to the downstream end (right end) of the throttle body 33a. A first passage main body 33b which is a portion is connected.

The first passage body 33b is configured to connect the throttle body 33a to the supercharger 34, as shown in FIG. Specifically, the first passage main body 33b is formed in a long cylindrical shape with the openings at both ends directed to the left and right. The first passage body 33 b is disposed in front of the engine body 10 so as to be substantially coaxial with the throttle body 33 a. More specifically, as can be seen from FIGS. 7 to 8, the first passage main body 33 b gradually expands in diameter from one side to the other side (specifically, from the left side to the right side) in the cylinder row direction. It is formed. While the downstream end of the throttle body 33a is connected to the upstream end (left end) of the first passage body 33b as described above, the gas intake portion of the turbocharger 34 is connected to the downstream end (right end) thereof. It is done.

In the first passage body 33b, a branch portion 33d connected to the bypass passage 40 is also opened. The branched portion 33d is formed on the upper surface of the first passage body 33b, and is connected to the upstream portion (a bent pipe portion 45 described later) of the bypass passage 40 (see FIG. 7).

The fresh air that has been cleaned by the air cleaner 31 and flows into the first passage 33 passes through the throttle valve 32 and reaches the first passage body 33 b. This fresh air flows into the bypass passage 40 via the branch portion 33d described above during natural suction, while it joins with the gas flowing backward in the bypass passage 40 during supercharging, from the downstream end of the first passage body 33b. It is drawn into the turbocharger 34 (see also FIG. 4).

Hereinafter, the passage structure on the turbocharger 34 side and the structure of the bypass passage 40 will be described in order.

-Passage structure on the turbocharger side-
First, the passage structure on the turbocharger 34 side will be described in detail.

The supercharger 34 as a roots blower includes first and second rotors 341 and 342 having rotation axes extending along the cylinder row direction, and a rotor chamber 343 accommodating the respective rotors 341 and 342. The first and second rotors 341 and 342 are juxtaposed in a row direction orthogonal to the central axis direction of the respective rotors 341 and 342. The supercharger 34 further includes a casing 34 b constituting a rotor chamber 343 and a drive pulley 34 d for rotationally driving the respective rotors 341 and 342, via a drive belt 81 wound around the drive pulley 34 d. It is connected to the crankshaft 15. The aforementioned electromagnetic clutch 34a is interposed between the drive pulley 34d and each of the rotors 341 and 342, and the supercharger 34 is connected via the crankshaft 15 by switching between disconnection and connection of the electromagnetic clutch 34a. Transmit the driving force to the vehicle, or interrupt the transmission of the driving force.

In this configuration example, the above-mentioned central axis direction coincides with the cylinder row direction (see FIG. 7). Therefore, in the following description, the central axis direction is simply referred to as the cylinder row direction. On the other hand, although the alignment direction substantially coincides with the vertical direction, the alignment direction is slightly inclined with respect to the same direction. That is, as shown by a straight line La in FIG. 9, although the first rotor 341 and the second rotor 342 are arranged in order from the lower side, the second rotor 342 located substantially above the first rotor 341 Slightly protruding forward. Since the second rotor 342 protrudes forward, the alignment direction is inclined slightly forward from the rear side as it goes upward from the lower side.

The casing 34 b is formed in a cylindrical shape extending in the cylinder row direction, and divides a rotor chamber 343 for accommodating the rotors 341 and 342 and a flow path of gas passing through the turbocharger 34. Specifically, the casing 34b is formed in a substantially cylindrical shape extending in the cylinder row direction and having the left end and the front face open, and as shown in FIG. On the other hand, they are disposed so as to be substantially coaxial while leaving a predetermined distance and slightly offset with respect to the first passage 33.

At the left end in the longitudinal direction of the casing 34b, an introduction portion for sucking in the gas compressed by the respective rotors 341 and 342 is opened, and the downstream end of the first passage 33 (specifically, the downstream end of the first passage body 33b ) Is connected. On the other hand, at the front of the casing 34b, as shown in FIGS. 8-9, the discharge part 34c for discharging the gas compressed by the respective rotors 341 and 342 is opened, and the upstream end of the second passage 35 (Upper end) is connected.

As can be seen from FIG. 6, the discharge portion 34c is formed as a triangular opening in which one side extends in the vertical direction and the other two sides are inclined with respect to the left-right direction.

The opening of the discharge portion 34c is formed along the direction in which the first and second rotors 341 and 342 are arranged when viewed in the cross section shown in FIG. Therefore, in consideration of the fact that the alignment direction is inclined with respect to the vertical direction, the opening of the discharge portion 34c is also inclined with respect to the vertical direction. Specifically, the discharge part 34c is inclined from the rear side to the front side as it goes from the lower side to the upper side along the vertical direction. That is, the discharge part 34c is inclined and opened on the lower side (the core 36a side of the intercooler 36) in the vertical direction.

As a result of the inclination as described above, the upper portion of the discharge portion 34c protrudes forward. Specifically, as shown by a straight line Li in FIG. 9, the discharge portion 34c is disposed on the front side of the upper end of the core 36a.

The drive pulley 34d is configured to rotationally drive the rotor housed in the casing 34b. Specifically, the drive pulley 34d is formed in an axial shape that protrudes from the right end of the casing 34b and extends substantially coaxially with both the first passage 33 and the casing 34b. The drive belt 81 is wound around the tip of the drive pulley 34d, and as described above, the crankshaft 15 is drivingly connected to the supercharger 34 according to the switching state of the electromagnetic clutch 34a. There is.

The supercharger 34 is disposed above the accessories. Specifically, as shown in FIG. 2, the drive pulley 34 d of the turbocharger 34 is disposed immediately above the alternator 91.

The second passage 35 is configured to connect the supercharger 34 to the intercooler 36, as shown in FIG. 9 and the like. The second passage 35 is formed to extend substantially in the vertical direction so that the supercharger 34 and the intercooler 36 are vertically adjacent to each other.

Specifically, the second passage 35 is configured as a flat rectangular tubular duct portion extending substantially in the vertical direction and having a short depth in the front-rear direction with respect to the passage width in the cylinder row direction.

Further, the second passage 35 has an upper upstream end 35a that opens substantially rearward and a lower downstream end 35b that opens substantially downward, and the upstream end While the portion 35a and the discharge portion 34c of the turbocharger 34 are connected to each other, the downstream end portion 35b and the introduction portion 36d of the intercooler 36 are connected to each other.

The upstream end 35a of the second passage 35 opens obliquely upward and rearward, and is slightly inclined with respect to the front-rear direction. Specifically, when viewed in the cross section shown in FIG. 9, the opening edge of the upstream end portion 35a extends from the rear side to the front side as it goes from the lower side to the upper side (perpendicular to the straight line Lu in FIG. See the direction). Therefore, the upper inner wall at the opening edge of the upstream end 35a protrudes slightly more forward than the lower inner wall at the opening edge.

Further, the upstream end 35 a of the second passage 35 is opened in a rectangular shape, and is offset to the right with respect to the discharge port of the turbocharger 34 as shown in FIG. 6.

The second passage 35 extends substantially straight downward from the upstream end 35a, and is then connected to the introduction portion 36d of the intercooler 36 via the downstream end 35b provided at the lower end thereof.

Of the inner wall near the upstream end 35a, the inner wall facing the discharge portion 34c of the turbocharger 34 is, as shown in FIG. A curved portion 351 is formed so as to be convex toward the opposite side (front side in this example) of the machine 34.

The downstream end 35 b of the second passage 35 opens obliquely downward and rearward, and is slightly inclined with respect to the vertical direction. Specifically, when viewed in the cross section shown in FIG. 9, the opening edge of the downstream end 35 b extends from the upper side to the lower side as it goes from the rear side to the front side. The front inner wall at the opening edge of the downstream end 35 b protrudes slightly lower than the rear inner wall at the opening edge.

Then, as shown in FIG. 6, the flow passage cross-sectional area at the downstream end 35b of the downstream end 35b of the second passage 35 extends from the upstream end 35a of the second passage 35 to the downstream end 35b. A narrow portion 35c is provided which is smaller than the flow passage cross-sectional area in each of the downstream end 35b and the portion from the downstream end 35b to the introduction portion 36d of the intercooler 36.

Specifically, the passage width of the downstream end 35b in the cylinder row direction is configured to be shorter than the passage width of the upstream end 35a and the introduction portion 36d in the same direction. As the passage width is narrowed, the cross-sectional area of the flow passage is reduced, whereby the narrowed portion 35c is provided at the downstream end 35b.

In this configuration example, as shown in FIG. 6, the narrow portion 35 c is formed in a pair of left and right necks. In addition, the narrow portions forming the narrow portion 35c may be formed in one of the left and the right without being a pair of the left and the right.

As described above, the intercooler 36 according to the present embodiment is configured to be water-cooled, and is attached to the core 36a having a gas cooling function and to the side of the core 36a as shown in FIGS. A core connection portion 36b, a housing 36c configured to receive the core 36a, and a gas introduction portion 36d of the intercooler 36 connected to the discharge portion 34c of the turbocharger 34 via the second passage 35; Is equipped. Although details will be omitted, a water supply pipe for supplying cooling water to the core 36a and a drainage pipe for discharging the cooling water from the core 36a are connected to the core connection portion 36b.

The core 36 a is formed in a rectangular shape, and is supported in a posture in which one side surface (rear surface) of the core 36 a faces the engine body 10. Specifically, the core 36a is supported in a slightly inclined posture with respect to the front-rear direction such that the front surface is directed obliquely upward and forward while the rear surface is directed obliquely downward and backward. The front surface of the core 36a constitutes the inflow surface of the gas, while the rear surface of the core 36a constitutes the outflow surface of the gas, which is the widest surface of the core 36a.

Although not shown, a plurality of water tubes each having a flat cylindrical thin plate material are arranged in the core 36a, and corrugated corrugated fins are connected to the outer wall surfaces of the water tubes by brazing or the like. ing. With this configuration, the cooling water supplied from the water supply pipe is introduced into each water tube to cool the high-temperature gas. Cooling water warmed by cooling the gas is drained from each water tube through a drain. Further, by providing the corrugated fins, the surface area of each water tube is increased to improve the heat radiation effect.

The core connection portion 36b is a rectangular thin plate-like member, and is attached to the left side surface of the core 36a. The water supply pipe and the drainage pipe, and the water tube are mutually connected via the core connection portion 36b. The core connection portion 36 b constitutes a left side wall portion of the intercooler 36, and constitutes a housing space of the core 36 a together with the housing 36 c.

The housing 36 c is disposed below the casing 34 b constituting the supercharger 34, and defines a housing space of the core 36 a, and between the second passage 35 and the third passage 37 in the intake passage 30. Constitute a flow path interposed between the

Specifically, the housing 36c is formed in the shape of a rectangular thin box whose rear surface side is open, and is supported at the lower position of the casing 34b in such a posture that the rear surface and the engine main body 10 face each other. Similar to the casing 34 b of the turbocharger 34, the rear surface is disposed at a predetermined distance from the front surface of the engine body 10. The upstream end of the third passage 37 is connected to the opening 36 e on the rear surface side.

The housing 36 c is also open on the left side. Although the details are omitted, the opening is configured as an insertion port when the core 36a is accommodated inside the housing 36c, and is closed by the core connection portion 36b.

On the other hand, a gas introducing portion 36d is integrally connected to the front side of the housing 36c, and the gas is supplied to the core 36a in the housing 36c through the opening of the introducing portion 36d.

The introduction portion 36 d extends from the front opening of the housing 36 c and extends from the front surface of the core 36 a accommodated in the housing 36 c toward the turbocharger 34. And the downstream end part 35b of the 2nd channel | path 35 is connected to the end (upper end) by the side of the turbocharger 34 in the introductory part 36d.

Specifically, the introducing portion 36 d extends gradually from the rear side to the front side as it goes upward from the front surface of the core 36 a (see Ld in FIG. 9). In other words, the introduction portion 36d is located on the core 36a side (rear side) from the opposite side (front side) of the core 36a in the longitudinal direction of the vehicle as it goes from the turbocharger 34 side to the front face of the core 36a in the vehicle height direction. It will extend in close proximity to the side).

The upper end of the introduction portion 36d is substantially at the same height as the upper end of the housing 36c in the vehicle height direction, and opens obliquely upward and forward.

Also, as can be seen from FIG. 9, the rear wall of the introducing portion 36d is connected to the upper edge of the housing 36c, while the front wall 362 of the introducing portion 36d is connected to the lower edge of the housing 36c There is. With such a configuration, the inner wall portion (the inner side of the wall portion 362) constituting the introducing portion 36d extends along the side surface of the core 36a on one side in the vehicle longitudinal direction, that is, the front surface of the core 36a. .

Here, returning to the description of the entire intercooler 36, as shown in FIG. 10, the intercooler 36 is disposed between the engine body 10 and the aforementioned radiator 93 in the vehicle longitudinal direction.

The front wall portion 362 of the introduction portion 36d of the intercooler 36 is formed to be concave toward the radiator 93 when viewed in a cross section in a plane including the vehicle height direction and the vehicle longitudinal direction. By doing this, the radiator 93 and the introduction portion 36d can be separated as much as possible.

Thus, the introduction portion 36d of the intercooler 36 functions as a passage that guides the gas that has passed through the second passage 35 to the core 36a housed in the housing 36c, rather than a simple opening. In that respect, this introducing part 36 d is equivalent to function as the downstream end of the relay passage 80.

The third passage 37 is a passage integrally formed with the surge tank 38 and the independent passage 39, and is configured to connect the intercooler 36 to the surge tank 38 as shown in FIG. .

The surge tank 38 extends in the cylinder row direction, and is formed in a substantially cylindrical shape whose both ends in the same direction are closed. As described above, the surge tank 38 is disposed opposite to the upstream end of the intake port 18 across the plurality of independent passages 39. As will be described later, when the plurality of independent passages 39 are respectively formed into a short cylindrical shape, the surge tank 38 is located near the inlet (upstream end) of the intake port 18 in combination with such an arrangement. Become. This is effective in shortening the flow path length from the surge tank 38 to the intake port 18.

Further, as shown in FIG. 11, the downstream end of the third passage 37 is connected to the bottom of the surge tank 38. Specifically, an inlet having a substantially circular cross section is opened at the center of the inner bottom surface of the surge tank 38 (specifically, at the center in the cylinder row direction), and the downstream end of the third passage 37 is The part is connected to the surge tank 38 via its inlet.

Further, on the rear surface of the surge tank 38, four sets (that is, eight in total) are formed in a state where two independent passages 39 forming one set are aligned along the cylinder row direction. Each of the eight independent passages 39 is formed as a short cylindrical passage extending substantially straight toward the rear in a vehicle mounted state, and one end side (upstream side) communicates with the space in the surge tank 38 On the other hand, the other end side (downstream side) is opened at the engine body 10 side (rear side).

The four independent passages 39 are disposed to correspond to the four intake ports 18, respectively, and the parts forming the third passage 37, the surge tank 38, the independent passage 39, etc. When assembled, each independent passage 39 and the corresponding intake port 18 constitute one passage.

As described above, the downstream portion of the bypass passage 40 is bifurcated, and the downstream ends of the branched passages (hereinafter referred to as “branch passages” 44 b and 44 c) are both the top surface of the surge tank 38. It is connected to the.

In order to realize such a connection structure, on the upper surface of the surge tank 38, first and second introduction portions are arranged at intervals in the cylinder row direction and configured to communicate the inside and the outside of the surge tank 38. 38c, 38d are provided.

The downstream end of one branch passage 44b is connected to the first introduction portion 38c located on one side (right side) of the first and second introduction portions 38c and 38d in the cylinder row direction. The downstream end of the other branch passage 44c is connected to the second introduction portion 38d located on the other side (left side) (see also FIG. 12).

At the time of supercharging, the output from the crankshaft 15 is transmitted through the drive belt 81 and the drive pulley 34d with the operation of the engine 1 to rotate the first and second rotors 341 and 342. As each rotor rotates, the turbocharger 34 compresses the gas sucked from the first passage 33 and discharges it from the discharge portion 34 c. The exhaled gas flows into the second passage 35 disposed in front of the casing 34b.

As shown in FIG. 10, the gas discharged from the turbocharger 34 and flowing into the second passage 35 flows downward from the discharge part 34 c of the turbocharger 34 along the second passage 35.

Subsequently, the gas that has passed through the second passage 35 flows into the interior of the housing 36c from the gas introduction portion 36d, and flows rearward from the front side. The gas flowing into the inside of the housing 36c is cooled by the cooling water supplied to the water tube when passing through the core 36a. The cooled gas flows out of the rear opening 36 e of the housing 36 c and flows into the third passage 37.

Then, as shown by arrow A0 in FIG. 11, the gas flowing from the intercooler 36 into the surge tank 38 via the third passage 37 is temporarily stored in the surge tank 38, and thereafter, passes through the independent passage 39. It is supplied to the intake port 18 of each cylinder 11.

-Structure of bypass passage-
Hereinafter, the configuration of the bypass passage 40 will be described in detail.

As described above, the bypass passage 40 branches and extends from the first passage body 33 b so as to bypass the turbocharger 34 and guide the gas to the combustion chamber 16.

Specifically, as shown in FIG. 7 and FIG. 12, the bypass passage 40 extends from the branch 33d opened in the first passage main body 33b diagonally upward to the left and then folded back to the right to be substantially straight. Extend to After the bypass passage 40 has a portion extending to the right reaching the vicinity of the center of the surge tank 38 (specifically, the vicinity of the center in the cylinder row direction), the bypass passage 40 is turned obliquely downward and to the rear. Bifurcated into two legs. Each branched branch is connected to the upper surface of the surge tank 38.

Here, the bypass passage 40 includes a curved pipe portion 45 for changing the flow direction of the gas flowing from the branch portion 33 d sequentially from the upstream side along the flow direction, a valve body 41 a in which the bypass valve 41 is built, and a valve A straight pipe portion 43 for guiding the gas that has passed through the body 41a to the right and a gas that has passed through the straight pipe portion 43 are directed diagonally downward and backward, and then branched into two branches and connected to the surge tank 38 And a branch pipe portion 44.

The bent pipe portion 45 is formed in a cylindrical shape extending substantially straight rightward from the branch portion 33d and then extending obliquely leftward and upward, and at the upper position of the first passage 33, the lower portion and the right portion are formed. It is arranged in the posture which turned the opening at and.

In the curved pipe portion 45, the portion extending diagonally upward to the left from the branch portion 33d is configured to gradually expand in diameter as it goes diagonally downward to the right in the opposite direction to the direction. Such a configuration is advantageous in enlarging the opening area of the branch 33 d.

Therefore, the gas flowing into the curved pipe portion 45 flows obliquely upward to the left, and then the flow direction is changed as the curved pipe portion 45 is folded back. As a result, the gas flowing through the curved pipe portion 45 flows inward (from the left to the right) from the outside in the cylinder row direction. As described above, the first passage body 33b is connected to the upstream end (lower end) of the curved pipe portion 45 via the branch portion 33d, while the downstream end (right end) of the curved pipe portion 45 is The upstream end (left end) of the valve body 41a is connected.

The valve body 41 a is formed in a short cylindrical shape, and as shown in FIG. 7, the openings at both ends are directed left and right above the first passage 33 and leftward with respect to the turbocharger 34. It is arranged in posture. The upstream end of the valve body 41a is connected to the downstream end of the curved pipe 45 as described above, while the downstream end (right end) of the valve body 41a is the upstream end (left end) of the straight pipe 43 Is connected.

The valve body 41 a is formed in a short cylindrical shape, and as shown in FIG. 7, the openings at both ends are directed left and right above the first passage 33 and leftward with respect to the turbocharger 34. It is arranged in posture. The upstream end of the valve body 41a is connected to the downstream end of the curved pipe 45 as described above, while the downstream end (right end) of the valve body 41a is the upstream end (left end) of the straight pipe 43 Is connected.

The branch pipe portion 44 is composed of a bent passage 44a bent in an elbow shape, and two branched passages 44b and 44c branched in a tournament shape from the downstream end of the bent passage 44a. At the upper position of the surge tank 38, the upstream end of the bending passage 44a is directed leftward, and the two branched branch passages 44b and 44c are both directed obliquely downward and backward.

The flow path lengths of the two branch passages 44b and 44c are substantially the same, and the first branch passage 44b which is one branched branch passage extends from the branch point to the right along the cylinder row direction. Later, it is bent diagonally to the lower back. On the other hand, the second branch passage 44c, which is the other branched branch passage, extends leftward along the cylinder row direction from the branch point and is then bent diagonally downward and rearward. The downstream end of each of the two branch passages 44b and 44c is connected to the upper surface of the surge tank 38 as described above.

Further, the downstream end portion of the EGR passage 52 is connected to the curved pipe portion 45. Therefore, not only the gas flowing in from the first passage 33 and the gas flowing back from the surge tank 38 but also the external EGR gas flows into the bypass passage 40.

The lower wall surface 45a of the curved pipe portion 45 to which the downstream end of the EGR passage 52 is connected is formed to be recessed downward. The lower wall surface 45a constitutes a water receiving structure for receiving water.

At the time of natural intake, the gas flowing into the bypass passage 40 passes through each portion forming the bypass passage 40 to reach each cylinder 11. That is, the gas that has passed through the throttle valve 32 flows into the curved pipe portion 45 of the bypass passage 40 from the middle of the first passage 33 according to the opening / closing condition of the bypass valve 41. The gas which has passed through the curved pipe portion 45 and flowed into the valve body 41a flows rightward as shown by the arrows in FIG.

Subsequently, the gas having passed through the valve body 41 a flows to the right along the straight pipe portion 43 as shown by the arrow in FIG. 12 and then flows into the branch pipe portion 44. Then, as shown by the other arrows, the gas flowing into the branch pipe portion 44 is distributed to the first branch passage 44b and the second branch passage 44c after passing through the bending passage 44a, and each of the distributed gas It flows into the surge tank 38. The gas flowing into the surge tank 38 is supplied to the intake port 18 of each cylinder 11 via the independent passage 39.

On the other hand, at the time of supercharging, the gas flowing back from the surge tank 38 to the bypass passage 40 passes through each part of the bypass passage 40 in the opposite direction to that at the time of natural suction and flows into the first passage main body 33b.

(Configuration for engine downsizing and quietness improvement)
As described above, there are cases where the supercharger 34 and the core 36a are juxtaposed along the vertical direction from the viewpoint of downsizing of the engine 1. In this case, the supercharger 34 and the core 36a are mutually connected via the relay passage (specifically, the second passage 35 and the introduction portion 36d) 80 disposed on the front side of each. As a result, it is possible to combine the supercharger 34 and the intercooler 36 and to make the engine 1 more compact.

However, when such a relay passage 80 is provided, the pulsation generated in the discharge pressure of the turbocharger 34 acts on the wall surface of the relay passage 80, which may cause a radiation noise.

However, as shown in FIG. 9, the introducing portion 36 d functioning as the downstream end of the relay passage 80 moves from the supercharger 34 side to the core 36 a side in the vehicle height direction, and in the vehicle front-rear direction From the side to the core 36a side. In addition, as described above, the inner wall portion constituting the introducing portion 36d extends along the front surface of the core 36a.

That is, the introductory portion 36d extends straight to the lower side along the vehicle height direction, and is not bent right after the vehicle front-rear direction, but both in the vehicle height direction and the vehicle front-rear direction And extend obliquely.

When obliquely extending in this manner, the passage length of the relay passage 80 can be shortened as compared with the configuration bent as described above. As the passage length is shortened, the surface area of the inner wall of the relay passage 80 is reduced.

It is considered that the above-mentioned radiation noise is generated by the vibration of the relay passage 80 in response to the pulsation of the supercharger 34, and as described above, by reducing the surface area of the inner wall portion of the relay passage 80, It is possible to suppress the volume. Thus, the quietness of the engine 1 can be enhanced.

Further, as shown in FIG. 9, by devising the shape of the gas introduction portion 36 d in the intercooler 36, the introduction portion 36 d can be used as the downstream end of the relay passage 80.

In addition, as shown in FIG. 9, the second passage 35 can be configured to be short in the relay passage 80 by an amount that the introduction portion 36 d is extended toward the turbocharger 34 side. The second passage 35 is a portion directly connected to the discharge portion 34 c of the supercharger 34, and there is a concern that the generation of the radiation noise is caused by the proximity to the discharge portion 34 c. By configuring such a second passage 35 to be short, it is possible to suppress the volume of the emitted sound and to improve the quietness of the engine 1.

Further, by providing the curved portion 351 as shown in FIG. 8, it is possible to prevent the stress from being concentrated on the second passage 35. This is advantageous in increasing the rigidity of the second passage 35 and thus suppressing the volume of the emitted sound. Thus, the quietness of the engine 1 can be enhanced.

Further, as shown in FIG. 9, since the discharge part 34c of the turbocharger 34 is inclined toward the intercooler 36, it is advantageous in shortening the passage length from the discharge part 34c to the introduction part 36d of the intercooler 36. become. This is effective in enhancing the quietness of the engine 1.

Further, as shown in FIG. 10, the front wall portion 362 of the introduction portion 36d is formed to be convex toward the radiator 93, for example, by a portion that is concave toward the radiator 93, or convex As compared with the case where it is flatly formed without forming the space, it is separated from the radiator 93. Thus, the distance between the wall portion 362 and the radiator 93 can be more sufficiently secured.

Further, as shown in FIG. 6, in the relay passage 80, at least the narrowing portion 35c is provided in the flow passage cross-sectional area at the downstream side of the narrowing portion 35c (that is, the introduction portion 36d of the intercooler 36). It will be larger than the channel cross-sectional area at the site. Then, the entire introduction portion 36d functions as a so-called expansion chamber type silencer, and it is possible to reduce the radiation noise caused by the pulsation related to the discharge pressure of the turbocharger 34.

Other Embodiments
In the embodiment, the narrow portion 35c is provided in the second passage 35, but the present invention is not limited to such a configuration. For example, it may be provided in the introduction part 36d (specifically, the middle part of the introduction part 36d) of the intercooler 36.

Moreover, in the said embodiment, as shown in FIG. 9 etc., although the housing 36c and the introductory part 36d were integrally formed in the intercooler 36, it is not restricted to such a structure. The housing 36c and the introduction portion 36d may be separate parts. Further, the introduction portion 36d and the second passage 35 may be an integral part.

DESCRIPTION OF SYMBOLS 1 engine 10 engine main body 12 cylinder block 13 cylinder head 16 combustion chamber 30 intake passage 34 supercharger 34c discharge part 35 2nd passage (duct part)
351 Curved part 36 Intercooler (heat exchange device)
36a core (heat exchange section)
36c Housing 36d Introduction part (downstream end of relay passage)
80 relay passage 93 radiator

Claims (7)

An intake passage connected to a combustion chamber, a supercharger disposed in the intake passage, and a gas disposed downstream of the supercharger in the intake passage and passing through the supercharger A heat exchange device including a heat exchange unit configured to exchange heat between the supercharged engine, comprising:
The supercharger and the heat exchange unit are juxtaposed along a predetermined first direction,
When a direction orthogonal to the first direction is referred to as a second direction, the supercharger and the heat exchange unit are disposed on one side with respect to the turbocharger and the heat exchange unit, and the turbocharger and the heat exchange unit are mutually Further comprising a relay passage configured to connect to the
The downstream end of the relay passage extends along the side surface on one side in the second direction in the heat exchange section, and the downstream end is the heat from the turbocharger side in the first direction An engine with a supercharger characterized in that it extends gradually toward the heat exchange portion in the second direction as it goes to the exchange portion side. In the supercharged engine according to claim 1,
The relay passage is
A duct unit connected to the gas discharge unit of the turbocharger;
And a gas introduction unit of the heat exchange device connected to the discharge unit via the duct unit;
The downstream end of the relay passage is configured to include the introduction portion. In the supercharged engine according to claim 2,
The heat exchange device comprises a housing configured to receive the heat exchange portion,
The supercharger-equipped engine according to claim 1, wherein the introduction portion extends from the housing toward the supercharger, and the duct portion is connected to one end of the supercharger. In the supercharged engine described in claim 2 or 3,
An inner wall portion of the inner wall of the duct portion facing the discharge portion is curved so as to project toward the opposite side of the turbocharger when viewed in a cross section perpendicular to the first direction. A supercharged engine characterized by forming a part. The supercharged engine according to any one of claims 2 to 4
The supercharger-equipped engine according to claim 1, wherein the discharge portion is inclined and opened toward the heat exchange device in the first direction. The supercharged engine according to any one of claims 1 to 5,
An engine body having a cylinder head and a cylinder block;
And a radiator disposed on one side of the second direction with respect to the engine body,
The heat exchange device is disposed between the engine body and the radiator in the second direction,
The downstream end portion of the relay passage is formed so as to be concave toward the radiator when viewed in a plane including the first direction and the second direction. Machined engine. The heat exchange system includes: an intake passage connected to a combustion chamber; a supercharger disposed in the intake passage; and a heat exchange device disposed downstream of the supercharger in the intake passage; An apparatus with a supercharger comprising: a heat exchange unit configured to exchange heat with gas passing through the turbocharger; and a housing configured to receive the heat exchange unit. And
The supercharger and the heat exchange unit are juxtaposed along a predetermined first direction,
When a direction orthogonal to the first direction is referred to as a second direction, the supercharger and the heat exchange unit are disposed on one side with respect to the turbocharger and the heat exchange unit, and the turbocharger and the heat exchange unit are mutually Further comprising a relay passage configured to connect to the
The relay passage is
A duct unit connected to the gas discharge unit of the turbocharger;
And a gas introduction unit of the heat exchange device connected to the discharge unit via the duct unit;
The introduction portion extends from the housing toward the supercharger in the first direction, and the duct portion is connected to one end of the introduction portion on the supercharger side. With supercharged engine.

Images