JPH08312476A - Suction system for engine with super charger - Google Patents

Abstract

PURPOSE: To provide the suction system for an engine with a supper charger, which can unify a distribution factor of intake air to respective independent air intake passages. CONSTITUTION: In the suction system for an engine 1, a series of air intake passages from an inter cooler 10 to a serge tank 11 (air intake manifold 31) is so constituted that each angle formed by its axial line and the axial lines of independent air intake passages is less than 90 deg. in the vicinity of a serge tank 11, and they are connected from below. By such a reason, intake air coming in the inside of the serge tank 11 from the connected air intake passages, is hit against the ceiling surface of the serge tank 11 first, and it is reflected by the ceiling surface, so that it thereby flows in the independent air intake passages. In this place, it is dispersed in all directions when it is hit against the ceiling surface of the serge tank 11 so as to be reflected. This constitution thereby allows intake air to be uniformly distributed into the respective independent air intake passages, and the distribution factor of intake air to the respective independent air intake passages is thereby unified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake system for a supercharged engine.

[0002]

2. Description of the Related Art Generally, in a normal naturally aspirated engine, the negative pressure generated as the piston descends causes the air for fuel combustion to be drawn into the combustion chamber (hereinafter, this air for fuel combustion is taken in. The air pressure in the cylinder during the intake stroke does not rise above atmospheric pressure.
Therefore, the intake charge efficiency, and thus the engine output per unit displacement, does not become so high. Therefore, in order to increase the engine output without increasing the displacement, a supercharger that pressurizes intake air is provided in the intake passage. An engine with a supercharger is usually provided with an intercooler for cooling the high-temperature intake air discharged from the supercharger in order to further improve the intake charging efficiency and prevent knocking. Various types of turbochargers have been used (e.g., exhaust turbo supercharger, mechanical supercharger, etc.), but when it is necessary to increase the engine output especially at low speeds. A mechanical supercharger driven by an engine output shaft (for example, a roots pump, a Risholum pump, or the like) is used as the engine.

In an engine with a supercharger, a common intake passage, a supercharger, an intercooler, a bypass intake passage, a bypass intake passage opening / closing valve, a surge tank (intake collecting portion), an independent intake passage ( Each member such as the intake manifold) is arranged, but in order to effectively use the limited space in the engine room, these members are formed or laid out so as to have a shape as compact as possible as a whole. There is a need. Therefore, in the conventional engine with a supercharger, in order to make the overall shape of the intake device compact,
Intercooler, bypass intake passage, bypass intake passage opening / closing valve, surge tank, independent intake passage (intake manifold)
Etc. are collectively arranged on one side of the engine body (see, for example, JP-A-4-308320).

[0004]

By the way, in the conventional supercharged engine in which the respective members constituting the intake device are arranged on one side of the engine body, the intake air flowing out from the intercooler is After flowing into the intake manifold via one connected intake passage, it is distributed to each independent intake passage, but at that time, there is a problem that the distribution ratio of intake air to each independent intake passage is not uniform. is there. That is, the intake air that has flowed into the intake collecting portion from one connected intake passage is likely to flow into the independent intake passage near the connected intake passage. Therefore, the closer the independent intake passage to the connected intake passage, the more the distribution ratio of the intake air. Because it will be higher. Therefore, there is a problem that the output of each cylinder becomes non-uniform and the rotational stability of the engine deteriorates.

Further, in such a conventional engine with a supercharger, each member constituting the intake device is arranged on one side of the engine main body in an attempt to make the intake device compact. , Supercharger, intercooler,
There is a problem in that compactness has not been sufficiently achieved due to the fact that the passage connecting each member such as the surge tank or the bypass intake passage is bulky.

Further, in the engine with a supercharger disclosed in, for example, Japanese Patent Laid-Open No. 4-308320, the intercooler is arranged on the middle side of the engine body, so that the engine body allows ventilation to the intercooler. Hindered
There is a problem (the running wind does not hit sufficiently) and the cooling performance of the intercooler cannot be enhanced sufficiently.

The present invention has been made in order to solve the above-mentioned conventional problems, and is an intake device for an engine with a supercharger capable of making the distribution ratio of intake air to each independent intake passage uniform. Aim to get. Another object of the present invention is to obtain an intake device for a supercharged engine having a compact structure that facilitates the layout of various members in the engine room. Furthermore, it aims at obtaining the intake device of the engine with a supercharger which can fully improve the cooling performance of an intercooler.

[0008]

The first aspect of the present invention, which has been made to achieve the above object, includes an intercooler for cooling the intake air discharged from the supercharger and a connection intake passage from the intercooler. An intake manifold including an intake collecting portion that receives intake air, and an independent intake passage for each cylinder that is arranged at a lower position relative to the intake collecting portion and guides the intake air in the intake collecting portion to each cylinder, In an intake device for a supercharged engine arranged on one side of an engine body, an intercooler is arranged at a position relatively above the intake collecting portion and apart from the engine body. At the same time, the intake air outlet of the intercooler is arranged at the lower end of the intercooler, and the connecting intake passage has an axis at the connecting portion to the intake collecting portion and the intake collecting passage of the independent intake passage. Is connected to the intake air collecting portion from below and is also curved in a substantially U shape to be connected to the intake air outflow port of the intercooler and the intake air collecting portion so that the axis of the connecting portion to the portion forms an acute angle. It is characterized by that.

According to a second aspect of the present invention, in the intake system for a supercharged engine according to the first aspect of the present invention, a duct for guiding cooling air to the intercooler is provided above the intake collecting portion. It is characterized by being present.

According to a third aspect of the present invention, in the intake system for a supercharged engine according to the second aspect of the present invention, the intercooler is a laminated heat exchanger having intake air tanks at both ends. It is characterized by being.

A fourth aspect of the present invention is an intake system for an engine with a supercharger according to the second aspect of the present invention, wherein the supercharger is a mechanical supercharger. Is arranged below the intake collecting portion, and the connection intake passage is arranged behind the mechanical supercharger when viewed in the front-rear direction of the engine.

A fifth aspect of the present invention is an intake system for an engine with a supercharger according to the first aspect of the present invention, which is substantially U.
The EGR gas introduction port is provided in a portion of the character-shaped connection intake passage located above the lower end portion.

[0013]

In the first aspect of the present invention, the connecting intake passage is connected to the intake collecting portion from the lower side so that its axis and the axis of the independent intake passage form an acute angle near the intake collecting portion. Therefore, the intake air flowing into the intake collecting portion from the connection intake passage first hits the ceiling surface of the intake collecting portion, is repelled by the ceiling surface, and flows into the independent intake passage. Here, when the intake air collides with the ceiling surface of the intake collecting portion and bounces back, it is scattered in all directions in the intake collecting portion. For this reason,
Intake air is evenly distributed to each independent intake passage.
Further, since the intercooler is arranged above the intake collecting portion, that is, generally above the upper end portion of the engine body, ventilation to the intercooler is improved. Further, since the connecting intake passage is curved in a substantially U shape and is connected to the intake air outlet of the intercooler and the intake collecting portion, the intercooler and the intake manifold can be arranged close to each other.

In the second aspect of the present invention, basically the same operation as that of the intake device for the supercharged engine according to the first aspect of the present invention occurs. Further, since the duct for guiding the cooling air to the intercooler is provided above the intake air collecting portion, the ventilation to the intercooler is further improved.

In the third aspect of the present invention, basically, the same operation as that of the intake device for the supercharged engine according to the second aspect of the present invention occurs. Further, since the intercooler is a laminated heat exchanger, the intercooler is downsized.
Weight is reduced.

In the fourth aspect of the present invention, basically, the same operation as that of the intake device for the supercharged engine according to the second aspect of the present invention occurs. Further, since the supercharger is arranged below the intake manifold and the connection intake passage is arranged behind the supercharger, the supercharger, the intake manifold (intake manifold) and the connection intake passage are close to each other. Are placed.

In the fifth aspect of the present invention, basically, the same operation as that of the intake device for the supercharged engine according to the first aspect of the present invention occurs. Furthermore, the EGR inlet is
Since the U-shaped connection intake passage opens to a position above the lower end of the connection intake passage, highly corrosive condensed water generated when the EGR gas flows into the connection intake passage and is cooled is E
Does not flow into the GR passage.

[0018]

EXAMPLES Examples of the present invention will be specifically described below.
First, the schematic structure and function of an engine with a supercharger equipped with an intake device according to the present invention will be described with reference to FIG. 7. As shown in FIG. 7, the four-cylinder engine 1 burns the air-fuel mixture (a mixture of air and fuel) supplied from the independent intake passages 2 (four) in each combustion chamber (not shown) to generate combustion gas. (Exhaust gas) is discharged to the common exhaust passage 4 via the independent exhaust passages 3 (4 pieces). Here, the common exhaust passage 4 is provided with a catalytic converter 5 using a three-way catalyst that removes (purifies) harmful components such as NOx and HC in the exhaust gas.

Then, air for fuel combustion is applied to the engine 1.
A common intake passage 6 for supplying (hereinafter, referred to as intake air) is provided. In the common intake passage 6, an air cleaner 7 that removes suspended dust in the intake air and a throttle valve 8 that opens and closes in conjunction with an accelerator pedal (not shown) are arranged in this order from the upstream side in the flow direction of the intake air. And a Rishorum type mechanical supercharger 9 (Rishorum pump) driven by the engine output shaft 17 (crankshaft) via the V-belt (winding member), and pressurized by the supercharger 9. An intercooler 10 that cools the intake air that has become high in temperature is provided. The downstream end of the common intake passage 6 is
It is connected to a surge tank 11 that stabilizes the flow of intake air, and the upstream ends of the independent intake passages 2 are connected to the surge tank 11.

A bypass intake passage 12 is provided which connects a portion 6a upstream of the supercharger 9 and a portion 6c downstream of the intercooler 10 of the common intake passage 6. The bypass intake passage 12 is provided with this bypass intake passage 12. An on-off valve 13 for opening and closing is provided. The open / close valve 13 is driven to open / close by an actuator 14. Here, when the supercharging pressure is high during supercharging, the opening / closing valve 13 is opened at an opening degree according to the supercharging pressure, and a part of intake air downstream of the supercharger is supercharged through the bypass intake passage 12. It is relieved upstream of the machine, and the supercharging pressure is maintained below a predetermined upper limit value. Further, the opening / closing valve 13 is fully opened during non-supercharging, and intake air is supplied to the combustion chamber through the bypass intake passage 12.

Further, the engine 1 is provided with a _first EGR device E ₁ and a second EGR device E ₂ that take out a part of the exhaust gas in the common exhaust passage 4 and supply it as EGR gas to the intake system. . Here, the first EGR device E
₁ supplies relatively high temperature EGR gas to the intake system in the non-supercharging region (low-speed low-load region) to raise the temperature of the intake air to improve the combustibility or ignitability of the air-fuel mixture and to reduce pumping loss. It is designed to be reduced (hot EGR).
On the other hand, the second EGR device E ₂ supplies a relatively low temperature EGR gas to the intake system in the supercharging region (high speed region or high load region) to lower the combustion temperature to reduce the NOx generation amount and the exhaust gas. It is designed to prevent the occurrence of heat damage in the exhaust system due to the high temperature of the engine (cold EGR).

The first EGR device E ₁ has one end (EG
The upstream end in the R gas flow direction) is connected to the common exhaust passage 4 upstream of the catalytic converter 5 in the exhaust gas flow direction, and the other end (downstream end in the EGR gas flow direction) is in the intake air flow direction. A first EGR passage 15 connected to the common intake passage 6c is provided downstream of the intercooler 10. Then, in the first EGR passage 15,
A first EGR control valve 16 that opens and closes the first EGR passage 15.
Is interposed.

On the other hand, in the second EGR device E ₂ , one end portion (upstream end in the EGR gas flow direction) has a common exhaust passage 4 downstream in the exhaust gas flow direction from the catalytic converter 5.
A second EGR passage 18 connected to the common intake passage 6a is provided at the other end (downstream end in the EGR gas flow direction) of the other end (upstream side of the supercharger 9 in the intake air flow direction). . Then, in the second EGR passage 18,
The second EG is sequentially arranged from the upstream side in the EGR gas flow direction.
A second EGR control valve 19 for opening and closing the R passage 18, and an EGR
A carbon trap 22 for removing particles such as carbon in the gas is interposed.

Here, in the supercharging region, the first EGR
While the control valve 16 is closed, the second EGR control valve 19 is opened, and the EGR is introduced into the intake system through the second EGR passage 18.
Gas is supplied. On the other hand, in the non-supercharging region, the first EGR control valve 16 is opened while the second EGR control valve 16 is opened.
The GR control valve 19 is closed so that the EGR gas is supplied to the intake system through the first EGR passage 15.

The specific structure and function of the engine 1 and its intake device will be described below with reference to FIGS. In the following, unless otherwise specified, the front side (the right side in FIGS. 1 and 2) and the rear side (FIGS. 1 and 2) of the engine 1
(Left side) are simply referred to as “front” and “rear” respectively, and engine 1
When viewed from the front, the right side (the front side of the paper in FIG. 1, the left side in FIG. 3) and the left side (the back side of the paper in FIG. 1, the right side in FIG. 3) are simply referred to as “right” and “left”, respectively.

As shown in FIGS. 1 to 3, the engine 1 is
The engine output shaft 17 (see FIG. 7) and the front wheel axle 23 are mounted sideways on the vehicle body so that they are oriented in the same direction (vehicle body width direction). The front end of the engine 1 faces the right side portion of the vehicle body, the rear end of the engine 1 faces the left side portion of the vehicle body, and the left side surface of the engine 1 faces the front end portion of the vehicle body.

In the engine 1, the engine output shaft 1
7 (see FIG. 7) has a crank pulley 41 coaxially attached to the front end thereof, a supercharger drive pulley 42 coaxially attached to the front end of the rotation shaft of the supercharger 9, and a water pump (not shown). ), A water pump drive pulley 43 is coaxially attached to the front end of the rotary shaft of FIG.
A V-belt 44 (wrapping member) is wound around 1, 42, 43. Here, the tension of the V-belt 44 is automatically adjusted by the automatic tensioner 45. Further, in the engine 1, the above-mentioned supercharger 9
And a water pump, a power steering pump 46, an alternator 47, an air conditioner compressor 48.
Etc. are driven by the engine output shaft 17. Incidentally, 49 is an idler pulley.

In the intake system of the engine 1, a common intake passage 6a (upstream intake passage) from the contact portion with the throttle body 25 to the supercharger 9 and a common intake passage from the intercooler 10 to the surge tank 11 are provided. Part of 6c (downstream intake passage portion) and bypass intake passage 12 are integrally formed in a single air casing 26 described later. That is, the portion R surrounded by the broken line in FIG. 7 is the air casing 26. Intercooler 1
The common intake passage 6c (connection intake passage) from 0 to the surge tank 11 is connected to the second connector 29 as described later.
And the second connection passage 30 and the above-mentioned downstream side intake passage portion and the like. Also, from the supercharger 9 to the intercooler 1
The common intake passage 6b reaching 0 is connected to the first connection passage 27 and the first connection passage 27.
And a connector 28.

In the intake system of the engine 1, the supercharger 9 that pressurizes the intake air, the intercooler 10 that cools the intake air discharged from the supercharger 9, and the intake air that flows out from the intercooler 10. The surge tank 11 for receiving the engine 1 and the surge tank 11 are in parallel or substantially parallel to the axis of the engine output shaft 17, respectively.
It is located on the right side of. Specifically, in the Rishorum type supercharger 9, the axis of the rotation shaft is the engine output axis.
It is arranged so that it is parallel to (front-back direction). The intercooler 10 is arranged so that its spreading surface is parallel to the engine output shaft axis, that is, the spreading surface faces the front of the vehicle body. The surge tank 11 is arranged such that its longitudinal axis is parallel to the engine output axis. The surge tank 11 is an intake air collecting passage that is integrally formed with the intake manifold 31 and has an elongated shape that extends in the axial direction of the engine output shaft. That is, the intake manifold 31 is a single member including the surge tank 11 and the independent intake passage 2.

Here, the intake manifold 31 is firmly fixed to the engine body by bolt fastening, and the supercharger 9 is firmly fixed to the engine body via the first mounting bracket 32 and the second mounting bracket 33. . Further, the intercooler 10 basically has a floating structure as described later, but the first stay 34 and the second stay 3 are
It is fixed to the engine main body side by using 5, and its swing is prevented. Both stays 34 and 35 are fixed to the engine body side via an elastic material (for example, rubber) so that the vibration of the engine body side to the intercooler 10 is suppressed or prevented.

The supercharger 9, the intercooler 10, and the surge tank 11 (a part of the intake manifold 31) are arranged in the following positional relationship. That is, in the left-right direction, the supercharger 9 and the surge tank 11 are arranged relatively to the left side of the intercooler 10, in other words, to the side close to the engine 1. Regarding the vertical direction,
The surge tank 11 is arranged at a position higher than the supercharger 9, and the intercooler 10 is arranged at a position higher than the surge tank 11.

Regarding the front-back direction, the supercharger 9 is
It is arranged from the front end position of the engine 1 to a position slightly rearward of the central portion. And intercooler 1
0 is arranged such that its front end is located rearward of the engine front end and its rear end is located forward of the engine rear end. That is, empty space portions are formed on the front side and the rear side of the intercooler 10, respectively.

According to this arrangement structure, the supercharger 9 and the intake manifold 31 having a large weight are arranged near the engine body, while the intercooler 10 having a small weight is arranged.
Is arranged at a position distant from the engine body, the assemblability of the intake device is improved and the intake device is easily supported.

Further, the intercooler 10 is the surge tank 1
Since it is arranged at a position higher than 1, that is, at a position higher than the upper end of the engine body, the ventilation of the intercooler 10 is improved, that is, the running air is liable to hit the intercooler 10, and the cooling performance of the intercooler 10 and thus the intake charge are increased. Efficiency is improved. Furthermore, the surge tank 11
A duct 40 for guiding cooling air (running air) to the intercooler 10 is provided above the intercooler 1.
Ventilation to 0 is further improved, and the cooling performance of the intercooler is further improved.

Further, vacant spaces are formed on the front side and the rear side of the intercooler 10, respectively. Therefore, the intercooler 10 is arranged at a central position in the engine room as viewed in the vehicle width direction. Therefore, an empty space is secured in the engine room near both ends in the vehicle width direction. And this empty space is the vacuum booster 3 of the brake.
Since the position is suitable for arranging 6 (master back), the layout of the vacuum booster 36 becomes easy. The vacuum booster 36 is arranged on either the left or right side depending on the position (left or right) of the handlebar. However, since the left and right empty spaces are secured in this way, The vacuum booster 36 can be easily laid out regardless of whether the vacuum booster 36 is arranged on either side.

The intercooler 10 is a laminated heat exchanger having an inlet side intake air tank 10a at the front end thereof and an outlet side intake air tank 10b at the rear end thereof, which is the inlet side intake air tank 10a. An intake air inlet for receiving intake air from the supercharger 9 is provided at the bottom (lower end), and an intake air outlet for sending intake air to the surge tank side is provided at the bottom (lower end) of the outlet-side intake air tank 10b. Is provided. Here, as viewed in the front-rear direction, the intake air inlet of the intercooler 10 is arranged at a position corresponding to the intake air outlet of the supercharger 9, and the intake air outlet of the intercooler 10 is the intake air inlet of the surge tank 11. It is located at the position corresponding to. According to this structure, the intercooler 10 is made lighter and smaller, so that the intake device is made more compact. Further, since the intake air inlet and the intake air outlet of the intercooler 10 are arranged at the lower end portion of the intercooler 10, the intercooler 10 can be easily connected to the surge tank 11 or the mechanical supercharger 9, and the intake air Assembling of the device is improved.

Here, the intake air outlet of the intercooler 10 and the intake air inlet of the surge tank 11 correspond to the supercharger 9
It is arranged behind the rear end portion (at a position displaced from the supercharger 9). Therefore, the passage connecting the intercooler 10 and the surge tank 11 is arranged close to the supercharger 9 without interfering with the supercharger 9, and the intake device is further downsized.

The intake air flows from the intake air discharge port of the supercharger 9 to the intake air flow inlet of the intercooler 10 through the first connection passage 27. The intake air discharge port and the intake air flow Since the inlet and the inlet are arranged close to each other in the front-rear direction, the path length of the first connection passage 27 is extremely short. Further, although the intake air flows from the intake air outlet of the intercooler 10 to the intake air receiving inlet of the surge tank 11 through the second connection passage 30 and the downstream side intake passage portion in the air casing 26, Since the intake air outflow port and the intake air reception port are arranged close to each other in the front-rear direction, the path length of the second connection passage 30 is extremely short. In this way, the first connecting passage 27 and the second connecting passage 30 are very short, so that the intake device can be made compact and its assembling property can be improved.

Here, the first connection passage 27 is connected to the intercooler 10 via a first connector 28 made of an elastic body (for example, rubber), while the second connection passage 30 is made of an elastic body.
It is connected to the intercooler 10 via a second connector 29 made of, for example, rubber. That is, the intercooler 10 has a so-called floating structure. Therefore, the propagation of the vibration of the supercharger 9 to the intercooler 10 is suppressed or prevented by the first connector 28, and the surge tank 1
The propagation of the vibration of No. 1 to the intercooler 10 is caused by the second connector
9 is suppressed or prevented.

As described above, since the supercharger 9 is rotationally driven by the engine output shaft 17 via the V belt, the supercharger 9 is subjected to vertical vibration and tension of the V belt. The resulting lateral vibration is induced. On the other hand, the intercooler 10 is only oscillated in the vertical direction. That is, basically, the supercharger 9 and the intercooler 10
And the vibration mode is different. However, since the intercooler 10 is connected to the supercharger 9 or the surge tank 11 via the elastic body as described above, a strong stress is applied to the connecting portion between the intercooler 10 and the supercharger 9 or the surge tank 11. It does not work, and the durability or reliability of the intake device is enhanced.

The specific structure and function of the air casing 26 (integrated passage) will be described below. The air casing 26 is arranged immediately behind the supercharger 9 and is fixed to the rear end of the supercharger 9. That is, the air casing 26
Are substantially integrated with the supercharger 9 and thus vibrate in substantially the same mode as the supercharger 9. The intercooler 10 is connected to the supercharger 9 via the first connection passage 27 and the first connector 28 at the front end portion, and is connected to the air casing 26 via the second connection passage 30 and the second connector 29 at the rear end portion. However, since the supercharger 9 and the air casing 26 thus vibrate in the same mode,
The vibration modes transmitted to the front end portion and the rear end portion of the intercooler 10 become the same, so that not much stress is induced in the intercooler 10, and the durability of the intercooler 10 and thus the intake device is enhanced. The first connector 28 or the second connector 29 in which vibration is transmitted from the supercharger 9 or the air casing 26 to the intercooler 10 is formed of an elastic body.
It is as described above that it is suppressed or prevented by.

As shown in FIGS. 4 to 6, the air casing 26 is provided with first to fourth openings 51 to 54 (connection ends). Here, the first opening 51 is bolted to the throttle body 25, and the second opening 52 is the supercharger 9.
Bolted to the casing (intake air suction port) of the
The opening 53 is connected to the surge tank 1 via a connecting pipe (not shown).
1 (intake manifold 31), the fourth opening 54
Are connected to the second connection passage 30.

In the air casing 26, the first
An upstream intake passage 60 that connects the opening 51 and the second opening 52 to each other and a downstream opening 61 that connects the third opening 53 and the fourth opening 54 to each other are formed. The upstream intake passage 60 is a part of the common intake passage 6a upstream of the supercharger 9, and the downstream intake passage 61 is a part of the common intake passage 6c downstream of the intercooler 10. Here, when the air casing 26 is mounted on the engine 1, the downstream side intake passage portion 61 is located above the upstream side intake passage portion 60.

The upstream side intake passage portion 60 and the downstream side intake passage portion 61 are partly partitioned by only a partition wall 63. A communication hole that penetrates the partition wall 63 and connects the upstream side intake passage portion 60 and the downstream side intake passage portion 61 is provided, and the communication hole serves as the bypass intake passage 12. The on-off valve 13 opens and closes the bypass intake passage 12 (communication hole). Since the air casing 26 also serves as the valve case of the on-off valve 13, it is not necessary to provide a special valve case, and the intake device can be made compact by this amount.

In this way, the air casing 26 is arranged by effectively utilizing the empty space formed behind the supercharger 9, so that the intake device can be made compact accordingly. Also,
In this way, since the single air casing 26 also serves as a plurality of intake passages, the number of parts of the intake device is reduced,
Its structure is simplified. Further, since the majority of the intake passage system can be supported only by supporting the air casing 26 in this manner, it becomes easy to support the intake passage system with sufficient supporting rigidity. Moreover, since the bypass intake passage 12 is a communication hole penetrating the partition wall 63, it is not necessary to provide a bypass intake passage, and the intake device can be made more compact.

In the vicinity of the bypass intake passage 12 (communication hole), the first EGR device E is installed in the downstream side intake passage portion 61.
_{The 1} (hot EGR) first EGR gas inlet 65 (that is, the downstream end of the first EGR passage 15) is open. Here, the first EGR gas introduction port 65 is arranged upstream of the bypass intake passage 12 (communication hole) when viewed in the intake air flow direction. The upstream side intake passage portion 60 has a second EGR of the second EGR device E ₂ (cold EGR).
The gas inlet 66 (that is, the downstream end of the second EGR passage 18) is open.

Thus, in the first EGR device E ₁ , the EGR gas is introduced into the intake system on the upstream side of the bypass intake passage 12, so that the EGR gas is introduced into a position deviated from the main flow of the intake air. , EG
The dispersibility of R gas in the intake air is improved. Also, EG
Condensed water produced by condensation of water vapor in R gas
When the valve 3 is opened, it flows down from the downstream side intake passage portion 61 to the upstream side intake passage portion 60 by gravity through the bypass intake passage 12 (communication hole), and then is vaporized in the supercharger 9. For this reason,
Condensed water having strong corrosiveness does not stay in the air casing 26, so that corrosion or rust generation in the air casing 26 is prevented or reduced, and its durability is enhanced.

As described above, a series of intake passages from the intake air outlet of the intercooler 10 to the intake air receiving inlet of the surge tank 11 (hereinafter referred to as the connection intake passage).
Is a second connector 29, a second connection passage 30, a downstream side intake passage portion 61 formed in the air casing 26,
The connecting intake passage is formed of an angle of 90 ° or less between the axis of the connecting portion to the surge tank 11 and the axis of the connecting portion of the independent intake passage 2 to the surge tank 11 (acute angle). ) Is connected to the surge tank 11 from the lower side. Furthermore, this connection intake passage is
It is curved in a substantially U shape, and one end is connected to the intake air outflow port of the intercooler 10 and the other end is connected to the intake air reception port of the surge tank 11.

Since the connection intake passage is formed in such a shape, the intake air flowing into the surge tank 11 from the connection intake passage first hits the ceiling surface of the surge tank 11 and is repelled by the ceiling surface. It will flow into each independent intake passage 2. Here, the intake air is surge tank 1
Surge tank 11 when it hits the ceiling surface of No. 1 and bounces back
Scatter in all directions within. Therefore, the intake air is evenly distributed to each independent intake passage 2, and each independent intake passage 2
The distribution ratio of intake air to the engine 1 is made uniform, and the rotational stability of the engine 1 is enhanced. Further, since the connection intake passage is curved in a substantially U shape and is connected to the intake air outlet of the intercooler 10 and the intake air inlet of the surge tank 11, the intercooler 10 and the intake manifold 31 (surge tank 11) are connected to each other. Can be arranged close to each other in the left-right direction, and the intake device can be made more compact.

The first EGR inlet 65 is substantially U-shaped.
Since it is located above the lower end of the character-shaped connecting intake passage, condensed water having strong corrosive property generated by condensation of water vapor in the EGR gas does not flow into the first EGR passage 15, and the first EGR passage
The durability of the passage 15 is improved.

[0051]

According to the first aspect of the present invention, the intake air that has flowed into the intake collecting portion from the connection intake passage first hits the ceiling surface of the intake collecting portion, is repelled by the ceiling surface, and becomes an independent intake passage. Although it flows in, when the intake air hits the ceiling surface of the intake air collection unit and bounces back, it is scattered in all directions in the intake air collection unit, so the intake air is evenly distributed to the individual intake air passages, and the intake air to the individual intake air passages is distributed. The distribution ratio of is uniformed. Further, since the ventilation to the intercooler is improved, the cooling performance of the intercooler is improved. Further, the intercooler and the intake manifold can be arranged close to each other, and the intake device can be made compact.

According to the second aspect of the present invention, basically, the same effect as that of the intake device for the supercharged engine according to the first aspect of the present invention can be obtained. Further, since the ventilation of the intercooler is assisted by the duct, the cooling performance of the intercooler is further enhanced.

According to the third aspect of the present invention, basically, the same effect as that of the intake device for the supercharged engine according to the second aspect of the present invention can be obtained. Further, since the intercooler is made smaller and lighter, the intake device is made more compact.

According to the fourth aspect of the present invention, basically, the same effect as that of the intake device for the supercharged engine according to the second aspect of the present invention can be obtained. Further, since the supercharger, the intake collecting portion (intake manifold) and the connection intake passage are arranged close to each other, the intake device can be made more compact.

According to the fifth aspect of the present invention, basically, the same effect as that of the intake device for the supercharged engine according to the first aspect of the present invention can be obtained. Furthermore, since the highly corrosive condensed water generated when the EGR gas flows into the connection intake passage and is cooled does not flow into the EGR passage, the occurrence of corrosion or rust in the EGR passage or the EGR control valve is prevented, The durability and thus the reliability of the EGR device or the intake device are enhanced.

[Brief description of drawings]

FIG. 1 is a side view of an engine equipped with an intake device according to the present invention.

FIG. 2 is a plan view of the engine shown in FIG.

FIG. 3 is a front explanatory view of the engine shown in FIG.

FIG. 4 is a plan view of an air casing.

FIG. 5 is a front explanatory view of an air casing.

FIG. 6 is a side view of the air casing.

FIG. 7 is a system configuration diagram of an intake device for the engine shown in FIG. 1.

[Explanation of symbols]

E ₁ ... 1st EGR device E ₂ ... 2nd EGR device 1 ... Engine 2 ... Independent intake passage 3 ... Independent exhaust passage 4 ... Common exhaust passage 6 ... Common intake passage 9 ... Supercharger 10 ... Intercooler 10a ... Inlet air tank 10b ... Outlet side intake air tank 11 ... Surge tank 12 ... Bypass intake passage 13 ... Open / close valve 15 ... First EGR passage 17 ... Engine output shaft 18 ... Second EGR passage 23 ... Front wheel axle 26 ... Air casing 27 ... First connection passage 28 ... 1st connector 29 ... 2nd connector 30 ... 2nd connection passage 31 ... Intake manifold 32, 33 ... 1st, 2nd mounting bracket 40 ... Duct 44 ... V belt 60 ... Upstream side intake passage part 61 ... Downstream side intake passage Part 63 ... Partition wall 65 ... First EGR introduction port 66 ... Second EGR introduction port

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Nobuo Hiramoto No.3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Engineering Co., Ltd. (72) Koji Kimura No.3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Engineering Co., Ltd.

Claims (5)

[Claims] 1. An intercooler for cooling intake air discharged from a supercharger, an intake collecting portion for receiving intake air from the intercooler via a connection intake passage, and a relative lower position with respect to the intake collecting portion. An intake manifold consisting of an independent intake passage for each cylinder that guides the intake air in the intake collecting portion to each cylinder, and an intake device for a supercharged engine arranged on one side of the engine body, The intercooler is arranged at a position relatively above the intake collecting portion and apart from the engine body, the intake air outlet of the intercooler is arranged at the lower end of the intercooler, and the connection intake passage is Make an acute angle between the axis of the connection to the intake manifold and the axis of the connection of the independent intake passage to the intake manifold, and contact the intake manifold from below. An intake device for an engine with a supercharger, which is connected to an intake air outflow port of an intercooler and an intake air collecting portion while being continuously connected to the intake air outlet. 2. The intake system for a supercharged engine according to claim 1, wherein a duct for guiding cooling air to the intercooler is provided above the intake collecting portion. Intake system for the engine. 3. The intake system for a supercharged engine according to claim 2, wherein the intercooler is a laminated heat exchanger having intake air tanks at both ends. Intake system for the engine. 4. The intake system for an engine with a supercharger according to claim 2, wherein the supercharger is a mechanical supercharger, and the mechanical supercharger is arranged below the intake collecting section. An intake device for an engine with a supercharger, characterized in that a connection intake passage is arranged behind the mechanical supercharger as seen in the front-rear direction of the engine. 5. The intake system for a supercharged engine according to claim 1, wherein an EGR gas introduction port is provided at a portion of the substantially U-shaped connection intake passage located above a lower end portion. Intake device for supercharged engine.