JP2021143628A - Intake system for engine - Google Patents

Abstract

To provide an intake system for an engine capable of avoiding the freezing of water content contained in blow-by gas.SOLUTION: An intake system for an engine 1 includes a turbosupercharger 5 having a turbine 52 to be driven by exhaust gas and a compressor 51 connected to the turbine 52 for compressing intake air, and a blow-by gas passage 71 for returning blow-by gas leaking into the engine into an intake pipe, wherein a flange part 54a is provided for introducing intake air into a compressor housing 54 via an air pipe 10, the air pipe 10 having a flange part 11a joined to the flange part 54a, a connection pipe part 12 joined to the blow-by gas passage 71, and a rib part 13 formed on the extension surface of the flange part 11a to connect the flange part 11a to the connection pipe part 12.SELECTED DRAWING: Figure 4

Description

The present invention relates to an engine intake device, and more particularly to an engine intake device including a turbocharger and a blow-by gas pipe.

Conventionally, a high-pressure EGR (Exhaust Gas Recirculation) passage that connects an exhaust passage on the upstream side of the turbine and an intake passage on the downstream side of the compressor, and an exhaust passage on the downstream side of the turbine and an intake passage on the upstream side of the compressor. An engine with a turbocharger having a low-pressure EGR passage that communicates with the engine and a blow-by gas passage that communicates with the crank chamber of the engine and the intake passage on the upstream side of the compressor is known (for example, Patent Document 1).

Moisture contained in blow-by gas (unburned gas) condenses and condensed water is generated in the blow-by gas passage when traveling at a low outside temperature in a cold region. When this condensed water is cooled by low-temperature intake air, the condensed water may freeze to form ice blocks. If a large ice block grown in the connecting pipe between the blow-by gas passage and the intake passage is sucked into the compressor side by the intake negative pressure, the impeller of the compressor wheel rotating at high speed may be damaged.
Therefore, a proposal has been made regarding a technology for preventing freezing of water contained in blow-by gas.

The antifreeze structure of the PCV passage of Patent Document 2 includes a PCV (Positive Crankcase Ventilation) passage for returning blow-by gas to the intake port and an EGR passage for returning the exhaust gas discharged from the engine to the intake port. A heating portion, which is a common portion between the outer wall of the EGR passage and the outer wall of the EGR passage, is provided on the upstream side of the blow-by gas introduction port and at a position adjacent to the blow-by gas introduction port.

JP-A-2019-127919 Japanese Unexamined Patent Publication No. 2013-151906

The antifreeze structure of the PCV passage of Patent Document 2 separates the EGR passage and the PCV passage by a single wall, so that the heat of the exhaust gas flowing through the EGR passage is transferred to the PCV passage in a state where the exhaust gas and the blow-by gas are separated from each other. Can be efficiently transmitted to the blow-by gas flowing through the air.
However, with the technique of Patent Document 2, there is a possibility that a sufficient heating effect on blow-by gas cannot be expected.

The purpose of EGR is to suppress the emission of Nox by lowering the combustion temperature, but normally, when traveling at low outside temperature where condensed water is generated in the blow-by gas passage, it is basically exhausted from the viewpoint of ensuring combustibility. Since the gas is not returned to the intake passage, the technique of Patent Document 2 cannot be expected to sufficiently avoid freezing of condensed water when traveling at a low outside temperature.

An object of the present invention is to provide an engine intake device or the like capable of avoiding freezing of water contained in blow-by gas.

The intake device of the engine according to claim 1 is a turbo supercharger having a turbine driven by exhaust gas and a compressor connected to the turbine and pressurizing the intake air, and blow-by gas leaked into the engine is returned to the intake pipe. In the intake device of an engine provided with a blow-by gas pipe, a compressor housing is provided in which the compressor is housed and has a first flange portion that can be connected to the intake pipe, and the intake pipe is joined to the first flange portion. A second flange portion, a connecting pipe portion joined to the blow-by gas pipe, and a rib portion formed on an extension surface of the second flange portion and connecting the second flange portion and the connecting pipe portion. It is characterized by having.

In the intake device of this engine, since the compressor is housed and a compressor housing having a first flange portion that can be connected to the intake pipe is provided, the compressor and the intake pipe can be connected via the first flange portion. The intake pipe is formed on an extension surface of the second flange portion joined to the first flange portion, the connecting pipe portion joined to the blow-by gas pipe, and the second flange portion, and the second flange portion. Since it has a rib portion that connects the portion and the connecting pipe portion, the heat conduction from the heated compressor to the connecting pipe portion can be effectively increased through the rib portion at the shortest distance.

According to a second aspect of the present invention, in the first aspect of the present invention, the intake pipe has an air pipe connecting the intake pipe and the compressor, and the air pipe has a second flange portion, a connecting pipe portion, and a rib portion. Is characterized by the formation of. According to this configuration, the second flange portion, the connecting pipe portion, and the rib portion can be arranged close to each other, and the heat conduction from the compressor to the connecting pipe portion can be further increased.

The invention of claim 3 is characterized in that, in the invention of claim 1, the air pipe is made of an aluminum alloy casting. According to this configuration, the heat conduction from the compressor to the connecting pipe portion can be further increased by forming the air pipe made of an aluminum alloy having a high heat conductivity.

The invention of claim 4 is characterized in that, in the invention of any one of claims 1 to 3, the axis of the connecting pipe portion intersects with the axis of the intake pipe. According to this configuration, the rib portion forming the connecting region between the connecting pipe portion and the second flange portion can be formed large.

The invention of claim 5 is the invention of any one of claims 1 to 4, wherein the connecting pipe portion has a third flange portion for joining the blow-by gas pipe, and the rib portion is the rib portion. It is characterized in that the second flange portion and the third flange portion are connected to each other. According to this configuration, heat can be conducted to the connecting portion where the condensed water tends to stay while enlarging the rib portion.

The invention of claim 6 is the invention of any one of claims 1 to 5, wherein the engine is vertically arranged substantially parallel to the vehicle body front-rear direction, and the turbocharger is one side portion of the engine. The compressor is provided on the rear side in the front-rear direction of the vehicle body with respect to the turbine. According to this configuration, it is possible to obtain heat convection from the turbine to the connecting pipe portion while avoiding that the connecting pipe portion is directly exposed to the traveling wind when traveling at a low outside temperature.

The invention of claim 7 is characterized in that, in the invention of claim 6, an insulator extending in the cylinder arrangement direction is provided between one side of the engine and the turbocharger. According to this configuration, it is possible to block the heat convection from the turbine to the engine and increase the heat convection toward the connecting pipe portion.

According to the intake device of the engine of the present invention, it is possible to avoid freezing of water contained in the blow-by gas by directing the heat of the compressor to the connecting pipe portion to which the blow-by gas pipe is joined by using heat conduction. ..

It is a schematic block diagram of the engine which concerns on Example 1. FIG. It is a side view of an engine. It is a perspective view of the engine seen from the rear right side. It is a perspective view around the compressor housing and the air pipe. It is a perspective view of an air pipe. It is a figure which shows the heat distribution of an Example model. It is a figure which shows the heat distribution of the comparative example model.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The following description exemplifies an application of the present invention to a vehicle engine, and does not limit the present invention, its application, or its use.

Hereinafter, Example 1 of the present invention will be described with reference to FIGS. 1 to 7.
First, a schematic configuration of the engine 1 according to the present invention will be described with reference to FIG.
The engine 1 is a gasoline engine (particularly, a 4-stroke internal combustion engine) mounted on a four-wheeled vehicle. The engine 1 is an in-line 6-cylinder longitudinal engine including six cylinders 21 arranged in a row, in which these cylinders 21 are arranged along the vehicle body front-rear direction.

As shown in FIG. 1, the engine 1 includes an engine main body 2, an intake device 3, an exhaust device 4, a turbocharger 5, a fuel supply device 6, a blow-by gas recirculation device 7, and the like.
The intake device 3 has upstream and downstream intake passages 31a and 31b connected to one side of the engine body 2, for example, an intake port formed on the left side. An air cleaner 32, a compressor 51 of the turbocharger 5, and the like are interposed in the upstream intake passage 31a. The fresh air is sucked into the upstream intake passage 31a via the air cleaner 32 and sent to the compressor 51 via the air pipe 10 described later. A throttle valve 33, an intercooler 34, a surge tank 35, and the like are interposed in the downstream intake passage 31b. Here, the intake passages 31a and 31b and the air pipe 10 correspond to intake pipes for flowing intake air into the combustion chamber.

The intake air flowing through the upstream intake passage 31a and the air pipe 10 is supercharged by the compressor 51, passes through the throttle valve 33, and is sent to the intercooler 34. The intercooler 34 cools the intake air temperature that has risen due to the compression action of the compressor 51. The throttle valve 33 is basically maintained at a fully open position or an opening degree close to this during the operation of the engine 1. Then, the valve is closed only when necessary, such as when the engine 1 is stopped.
The synthetic resin surge tank 35 is provided so as to form a predetermined volume chamber in the region near the connection portion between the intake port and the intake passage 31b, and aims to equalize the amount of intake air supplied to the combustion chamber of each cylinder. ing.

As shown in FIG. 1, the exhaust device 4 includes an exhaust passage 41 having an upstream end connected to an exhaust manifold 40 formed on the other side of the engine body 2, for example, the right side, a first EGR passage 42, and a second EGR passage. It has 43 mag. The exhaust manifold 40 is a collection of exhaust ports for the front three cylinders and exhaust ports for the rear three cylinders formed on the cylinder head 22.
A turbocharger 5, a catalytic converter 44, a GPF (Gasoline Particulate Filter) 45, and the like are provided in the middle of the exhaust passage 41 as exhaust system parts. The catalyst converter 44 is configured to include a three-way catalyst, and the GPF 45 is configured to be able to remove particulate matter contained in the exhaust gas.

The first EGR supplies a relatively high temperature EGR gas to the intake system to improve ignitability and reduce pumping loss. The first EGR passage 42 connects the cylinder head 22 (see FIGS. 2 and 3) of the engine body 2 and the intake passage 31b, and includes a first EGR valve 46 and a first EGR cooler 46a in the middle thereof. The second EGR supplies a relatively low temperature EGR gas to the intake system, and reduces the amount of NOx generated by lowering the combustion temperature. The second EGR passage 43 connects the exhaust passage 41 and the intake passage 31a, and includes a second EGR valve 47 and a second EGR cooler 47a in the middle thereof.

The turbocharger 5 is a water-cooled VG (Variable Geometry) turbocharger, which is provided with a plurality of movable vanes (not shown) whose angles can be changed, and adjusts the flow velocity of the exhaust gas flowing into the turbine 52. It controls the supply status. The turbocharger 5 includes a compressor 51 and a turbine 52. The compressor 51 and the turbine 52 are connected by a shaft 53. The shaft 53 is rotatably supported by a center housing 56 (see FIG. 2) via a bearing (not shown), and the center housing 56 has a hollow water jacket (not shown) through which cooling water can flow. It is formed.

As shown in FIG. 1, the fuel supply device 6 is pressurized by a fuel tank 61 mounted on the rear portion of the vehicle body, a high-pressure fuel pump 62 connected to the fuel tank 61 via a fuel pipe 64, and the fuel pump 62. It is equipped with a fuel rail 63 (fuel supply pipe) that distributes the fuel to the combustion chambers of each cylinder.

The blow-by gas recirculation device 7 includes a blow-by gas passage 71 (blow-by gas pipe). The blow-by gas passage 71 is connected from the inside of the head cover 23 (see FIG. 3) of the engine body 2 to the directly upstream portion of the compressor 51 in order to return the blow-by gas generated in the engine body 2 to the intake pipe. .. Specifically, the downstream end of the blow-by gas passage 71 is connected to the air pipe 10 that connects the upstream intake passage 31a and the compressor 51.

Next, the appearance configuration of the engine body 2 will be described.
As shown in FIGS. 2 and 3, in the engine body 2, a rectangular parallelepiped air cleaner 32 and the like are arranged in the left side region of the side wall portion, and the turbocharger 5 and the catalytic converter 44 are arranged in the right side region of the side wall portion. And GPF45 and the like are arranged. In FIGS. 2 and 3, the catalytic converter 44 and the GPF 45 are omitted for convenience of explanation. Hereinafter, in the figure, the arrow F direction will be described as the front in the front-rear direction of the vehicle body, the arrow L direction as the left side in the vehicle width direction, and the arrow U direction as the upper direction in the vehicle body vertical direction.

The intake air introduced from the intake duct (not shown) provided on the left front side of the engine body 2 is sent to the air cleaner 32 installed on the left side and the upper stage position of the front end of the engine body 2. The upstream intake passage 31a extends rearward from the region near the upper left side of the engine body 2. Then, the upstream intake passage 31a wraps around behind the engine body 2 and above the transmission (not shown), extends from the rear of the engine body 2 to a region near the right side of the engine body 2, and extends to the turbocharger 5 (not shown). It is connected to the compressor 51) from the rear side via an air pipe 10.

The downstream intake passage 31b extends from the compressor 51 of the turbocharger 5 to the left through the upper side of the engine body 2 to the region near the left side of the engine body 2. The intake air densified by the compression action of the compressor 51 is sent to the intercooler 34 arranged on the left side of the engine body 2. In the intercooler 34, the intake air whose temperature has risen due to the compression of the compressor 51 is cooled by exchanging heat between the cooling water supplied from the water pump (not shown) via the cooling water passage (not shown) and the high temperature intake air. It has been.

As shown in FIGS. 2 and 3, the turbocharger 5 is arranged so as to extend in the front-rear direction on the right side wall portion of the engine body 2 in the middle portion in the front-rear direction and in the upper portion corresponding to the cylinder head 22 and the head cover 23. It is installed. The turbocharger 5 has a compressor housing 54 accommodating a compressor 51, a turbine housing 55 formed in front of the compressor housing 54 accommodating a turbine 52, and a shaft 53 extending horizontally in the front-rear direction via bearings. It has a cast iron center housing 56 that supports the shaft.

The compressor housing 54 is formed of cast aluminum alloy and includes a flange portion 54a (first flange portion) at the rear end portion to which intake air can be introduced and to which the air pipe 10 can be connected. The turbine housing 55 is made of heat-resistant cast steel, and the rear end portion on the left side is connected to the gathering portion of the exhaust manifold 40. The exhaust gas that rotationally drives the turbine 52 is discharged from the discharge port 55a formed at the front end of the turbine housing 55. A catalytic converter 44 is connected in series to the discharge port 55a.

As shown in FIG. 2, an aluminum-plated steel plate insulator 24 is interposed between the front half of the turbocharger 5 and the upper half of the catalyst converter 44 and the right wall of the engine body 2. The insulator 24 is arranged in the front side of the front side portion of the compressor housing 54 and is arranged at a position corresponding to the first insulator portion 24a which is substantially orthogonal to the left and right direction and the front side portion of the compressor housing 54 and is arranged in the front-rear direction. It is provided with a second insulator portion 24b that is substantially orthogonal to each other. The second insulator portion 24b is formed in a substantially hat shape protruding forward in a plan view. As a result, the traveling wind introduced from the front of the vehicle and flowing backward in the right region of the insulator 24 is guided toward the compressor housing 54.

As shown in FIGS. 2 to 4, the blow-by gas passage 71 is formed of a flexible synthetic resin hose, and its pipe diameter is ½ or more of the pipe diameter of the downstream side intake passage 31b and the downstream side intake air is taken. It is set to be smaller than the pipe diameter of the passage 31b. A cylindrical blow-by gas lead-out portion 23a extending vertically is formed at the rear portion of the head cover 23 and at the center portion in the vehicle width direction.
The upstream end of the blow-by gas passage 71 is fitted and connected to the lead-out portion 23a, extends upward once, then moves downward toward the right side, and the downstream end is fastened to the air pipe 10 via the connecting portion 72. .. As a result, the moisture in the blow-by gas led out from the lead-out portion 23a is supplied to the air pipe 10 without passing through the flat portion.

Next, the air pipe 10 will be described.
As shown in FIGS. 2 to 4, the air pipe 10 is arranged on the rear side of the turbocharger 5 and connects the downstream end portion of the upstream intake passage 31a and the flange portion 54a of the compressor housing 54. .. The air pipe 10 is integrally formed of an aluminum alloy casting, and the thermal conductivity of the air pipe 10 is about 200 W / (m · K), which is the same as that of the aluminum alloy.
As shown in FIGS. 4 and 5, the air pipe 10 includes a cylindrical main body portion 11, a tubular connecting pipe portion 12 formed on the left side of the main body portion 11, and a main body portion 11 and a connecting pipe portion 12. It is provided with a rib portion 13 or the like for connecting between the ribs.

The main body 11 is formed in a cylindrical shape, and when the air pipe 10 is fixed to the compressor housing 54, the main body 11 is configured to have a rearward upward inclination that shifts upward toward the rear side. The main body portion 11 has a flange portion 11a (second flange portion) projecting outward in the radial direction on an extension surface orthogonal to the axis L1 at the front end portion. A pair of bolt holes are formed diagonally with respect to the axis L1 in the flange portion 11a, and the air pipe 10 is used with a pair of bolts 14 in a state where the flange portion 11a and the flange portion 54a are overlapped in a surface contact manner. Is fixed to the compressor housing 54.

The connecting pipe portion 12 is formed in a cylindrical shape having a diameter smaller than that of the main body portion 11, and is configured such that the axis L2 extends upward when the air pipe 10 is fixed to the compressor housing 54. The axis L2 extending upward is formed in a substantially right-curved shape so that the distance of the main body 11 from the axis L1 approaches the lower side, and the angle of intersection with the axis L1 is set to approximately 90 °.
The connecting pipe portion 12 has a flange portion 12a (third flange portion) projecting outward in the radial direction on an extension surface orthogonal to the axis L2 at the upper end portion. A single bolt hole is formed in the flange portion 12a, and the connecting portion 72 is fixed to the air pipe 10 by using a bolt (not shown) in a state where the flange portion 12a and the lower surface of the connecting portion 72 are overlapped in a surface contact manner. Has been done.

The rib portion 13 is formed in a substantially trapezoidal shape when viewed from the front, and connects the flange portion 11a and the connecting pipe portion 12. As shown in FIGS. 5 (b) and 5 (c), the rib portion 13 is placed on an extension surface orthogonal to the axis L1, specifically, on an extension surface of the flange portion 11a (rear surface portion). It is formed so as to extend to the left from the left outer peripheral portion (for example, a 1/4 arc portion) of the flange portion 11a. The left upper end portion of the rib portion 13 is connected to the front portion of the flange portion 12a, and the other left side portion is connected to the front portion of the outer peripheral wall portion of the connecting pipe portion 12.

Next, the operation and effect of the intake device of the engine according to the embodiment of the present invention will be described.
In explaining the operation and effect, a model MA having the same specifications as in the first embodiment and a model MB having the same specifications as the model MA except for the omission of the rib portion are prepared, and the connection pipe portion is provided based on CAD (Computer Aided Design) data. The heating effect was analyzed by CAE (Computer Aided Engineering). In this analysis, when the engine speed is 1500 rpm, the intake air filling efficiency is 0.86, the engine water temperature is set to 50 ° C, and the outside air temperature is set to -30 ° C, the temperature of the compressor housing H and the flange portion FA of the connecting pipe portion are set. The difference from the FB temperature (degree of temperature decrease) was evaluated.

The verification results will be described with reference to FIGS. 6 and 7.
FIG. 6 shows the temperature distribution of the model MA, and FIG. 7 shows the temperature distribution of the model MB.
As shown in FIG. 6, the temperature difference of the flange portion FA portion near the compressor housing H is about 5 ° C., the temperature difference of the flange portion FA portion far from the compressor housing H is about 9 ° C., and the average temperature difference is about 7 ° C. Met. As shown in FIG. 7, the temperature difference between the flange portion FB portion near the compressor housing H and the flange portion FB portion far from the compressor housing H was about 14 ° C. From the above, it was found that the rib portion R, which secures a large connecting region with respect to the connecting pipe portion, conducts a large amount of heat from the compressor housing H to the flange portion FA and contributes to the improvement of the heating effect.

According to the present embodiment, since the compressor 51 is housed and the compressor housing 54 having the flange portion 54a connectable to the intake pipe (intake passage 31a and the air pipe 10) is provided, the compressor housing 54 and the intake air are taken in through the flange portion 54a. The pipes can be connected. The intake pipe is formed on the flange portion 11a joined to the flange portion 54a, the connecting pipe portion 12 joined to the blow-by gas passage 71, and the extension surface of the flange portion 11a, and the flange portion 11a and the connecting pipe portion 12 Since the rib portion 13 is provided, the heat conduction from the heated compressor housing 54 toward the connecting pipe portion 12 can be effectively increased through the rib portion 13 in the shortest distance.

The intake pipe has an air pipe 10 that connects the upstream intake passage 31a and the compressor housing 54, and the flange portion 11a, the connecting pipe portion 12, and the rib portion 13 are formed on the air pipe 10, so that the flange portion 11a and the connecting pipe are formed. The portion 12 and the rib portion 13 can be arranged close to each other, and the heat conduction from the compressor housing 54 to the connecting pipe portion 12 can be further increased.

Since the air pipe 10 is made of an aluminum alloy casting, the air pipe 10 made of an aluminum alloy having a high thermal conductivity can be formed to further increase the heat conduction from the compressor housing 54 to the connecting pipe portion 12.

Since the axis L2 of the connecting pipe portion 12 intersects the axis L1 of the main body portion 11 which is an intake pipe, the rib portion 13 forming the connecting region between the connecting pipe portion 12 and the flange portion 11a is formed large. Can be done.

The connecting pipe portion 12 has a flange portion 12a for joining the blow-by gas passage 71, and the rib portion 13 connects the flange portion 11a and the flange portion 12a. Heat can be conducted by concentrating on the connection portion where it tends to stay.

Because the engine body 2 is arranged vertically substantially parallel to the front-rear direction, the turbocharger 5 is supported on one side of the engine body 2, and the compressor housing 54 is arranged behind the turbine housing 55. It is possible to obtain heat convection from the turbine housing 55 toward the connecting pipe portion while avoiding that the connecting pipe portion 12 is directly exposed to the traveling wind during traveling at a low outside temperature.

Since the insulator 24 extending in the cylinder arrangement direction is provided between one side of the engine body 2 and the turbocharger 5, heat convection from the turbine housing 55 to the engine body 2 is blocked and the connecting pipe portion 12 is provided. The amount of heat towards can be increased.
Further, since the second insulator portion 24b is formed in a substantially hat shape protruding forward in a plan view, the heat of the turbine housing 55 is generated from the gap between the second insulator portion 24b and the compressor housing 54 while rectifying the running wind. Can be transmitted to the connecting pipe portion 12 via the traveling wind.

Next, a modified example in which the embodiment is partially modified will be described.
1] In the above embodiment, an example of a 6-cylinder longitudinal gasoline engine has been described, but at least a longitudinal engine may be used, and the engine type, number of cylinders, model, arrangement form, etc. can be arbitrarily set. For example, a 4-cylinder diesel engine may be used.

2] In the above embodiment, an example of the air pipe 10 having the connecting pipe portion 12 on the left side of the main body portion 11 has been described, but the effect of the present invention can be obtained regardless of whether the connecting pipe portion 12 is arranged on the left or right side of the main body portion 11. It is possible. In consideration of compactness and improvement of thermal conductivity, it is preferable that the connecting pipe portion 12 is arranged between the main body portion 11 and the side wall portion of the engine main body 2.

3] In addition, a person skilled in the art can carry out the embodiment in a form in which various modifications are added to the above-described embodiment or in a combination of the respective embodiments without deviating from the gist of the present invention. It also includes various modified forms.

1 Engine 2 Engine body 5 Turbocharger 7 Blow-by gas recirculation device 10 Air pipe 11 Main body 11a Flange part (second flange part)
12 Connection pipe part 12a Flange part (third flange part)
13 Rib 24 Insulator 31a Upstream intake passage 51 Compressor 52 Turbine 54 Compressor housing 54a Flange (first flange)
55 Turbine housing 71 Blow-by gas passage

Claims (7)

An engine including a turbocharger having a turbine driven by exhaust gas and a compressor connected to the turbine and pressurizing intake air, and a blow-by gas pipe for returning blow-by gas leaked into the engine to an intake pipe. In the intake system
A compressor housing in which the compressor is housed and has a first flange portion that can be connected to the intake pipe is provided.
The intake pipe is formed on an extension surface of the second flange portion joined to the first flange portion, the connecting pipe portion joined to the blow-by gas pipe, and the second flange portion, and the second flange portion. An intake device for an engine, characterized by having a rib portion that connects the portion and a connecting pipe portion. The intake pipe has an air pipe connecting the intake pipe and the compressor.
The intake device for an engine according to claim 1, wherein the air pipe is formed with the second flange portion, the connecting pipe portion, and the rib portion. The engine cooling device according to claim 2, wherein the air pipe is made of an aluminum alloy casting. The intake device for an engine according to any one of claims 1 to 3, wherein the connecting pipe portion intersects the axis of the intake pipe. The connecting pipe portion has a third flange portion for joining the blow-by gas pipe.
The intake device for an engine according to any one of claims 1 to 4, wherein the rib portion connects the second flange portion and the third flange portion. The engine is arranged vertically, which is substantially parallel to the front-rear direction of the vehicle body.
The turbocharger is supported on one side of the engine,
The intake device for an engine according to any one of claims 1 to 5, wherein the compressor is arranged on the rear side in the front-rear direction of the vehicle body with respect to the turbine. The intake device for an engine according to claim 6, wherein an insulator extending in the cylinder arrangement direction is provided between one side portion of the engine and the turbocharger.

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