JPH0783065A - Air intake system of engine with turbo supercharger - Google Patents

Abstract

PURPOSE:To prevent torsion generated in an air intake communicating passage between compressor discharge openings caused by thermal expansion of a turbin part, deterioration of durability of the air intake communicating passage due to displacement in the longitudinal direction and breakage of connection parts with other systems or an engine main body in the case of serially arranging two turbo superchargers in the turbine axis direction by way of making turbines adjoin themselves. CONSTITUTION:A sequential twin turbo supercharger 10 serially arranging a primary turbo supercharger 7 and a secondary supercharger 8 in the turbine axis direction by way of having both of turbines 11, 13 adjoin themselves is provided, a collecting pipe 17 formed of an elastic material is arranged in the turbine axis direction, its one end is connected to a discharge opening of a primary compressor 12, and the other end is connected to a communicating pipe 18 of a metal material extending from a discharge opening of a secondary compressor 14. Thereafter, to the collecting pipe 17, an intake pipe communicated with an inter-cooler is connected, and on the communicating pipe of the metal material, a shutter valve 20 is set.

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 an engine equipped with two turbochargers.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Laid-Open No. 18393/1992.
As disclosed in Japanese Patent Publication No. 0, a turbocharger is provided with two turbochargers, one of which is a primary turbocharger that operates in the entire supercharge range from low to high engine revolutions, and the other is a high turbo range. A secondary turbocharger that operates only on
A so-called sequential twin turbo type supercharged engine is known. And in this sequential twin turbocharged engine, the two turbochargers are arranged in series in the turbine axial direction with the turbines next to each other.
It is general that the turbine casing is formed of an integral casting, an exhaust pipe connection port is provided in the center, and the discharge ports of both blowers are connected to an intake pipe by communicating with an intake communication passage in the turbine axial direction.

[0003]

When the two turbochargers are arranged in series in the turbine axial direction with the turbines next to each other as described above, the impeller of the turbine and the impeller of the compressor are both supercharged. It is advantageous in terms of cost to use a machine with common specifications, but in that case, arranging turbines next to each other in series means that
This means that the blades of the two left and right turbines are opposite to each other in the assembled state, the direction of the exhaust inlet is opposite, and the shape of the turbine casing is asymmetrical.
Therefore, the direction of thermal expansion of the turbine part, which becomes hot, is reversed, and twisting occurs in the intake communication passage connecting the discharge ports of both compressors, and this twisting improves the durability of the intake communication passage formed of the metal material. Adversely affect. In addition, when the two turbochargers are arranged in this way, the turbine casing is constrained at the exhaust manifold side connecting portion, so that there is a twist that causes the compressors on both sides to bend in the axial direction of the turbine due to thermal expansion. It is generated, whereby the intake communication passage, which is arranged on the opposite side of the manifold side connecting portion with the turbine shaft interposed therebetween, is pulled in the longitudinal direction and displaced, and any portion of another intake system or The connection with the engine body may be damaged due to stress concentration.

The present invention is intended to solve such a problem and is caused by thermal expansion of a turbine portion in an engine in which two turbochargers are arranged next to each other in series in the axial direction of the turbine. As a result of twisting and longitudinal displacement occurring in the intake communication passage between the compressor discharge ports, the durability of the intake communication passage deteriorates, and stress concentrates on other intake systems or their engine parts, leading to damage. The purpose is to prevent.

[0005]

SUMMARY OF THE INVENTION According to the structure of the present invention, a turbocharger for driving a turbine with exhaust gas and rotating a compressor via the turbine shaft by the exhaust gas is installed in the turbine axial direction so that the turbines are adjacent to each other. In an engine with a turbocharger that has two turbochargers connected in series and connects the compressor discharge ports of both turbochargers to the intake pipe in the turbo axial direction, connect the intake pipe of the intake communication passage Part and one turbo supercharger, for example, the part from the compressor discharge side of the primary turbo supercharger to be operated in the entire supercharging range from low rotation to high rotation of the engine to the intake pipe connection part is formed of an elastic material, The other turbocharger,
For example, the part from the compressor discharge side to the intake pipe connection part of the secondary turbocharger that operates only in a predetermined high rotation range is made of a metal material, and the shutter valve is provided in the communication passage part made of the metal material. Here, the turbocharger in which the portion from the compressor discharge side to the intake pipe connecting portion is formed of an elastic material is preferably the vehicle front side.

[0006]

[Operation] Since the two turbochargers are arranged in series in the turbine axial direction with the turbines next to each other,
The direction of thermal expansion of the turbine part, which has a high temperature, is reversed, twisting occurs in the intake communication passage that connects the discharge ports of both compressors, and the connecting part on the exhaust manifold side is restrained, which causes thermal expansion. When this occurs, a twisting that causes the compressors on both sides to bend in the axial direction of the turbine is generated, whereby the intake communication passage is pulled in the longitudinal direction and displaced. However, according to the present invention, the intake pipe connecting portion of the intake communication passage and one turbocharger, for example, from the compressor discharge side of the primary turbocharger that operates in the entire supercharging range from low rotation to high rotation of the engine Since the portion up to the intake pipe connecting portion is made of the elastic material, the twist and displacement generated in the intake communication passage are absorbed by the elastic material. Therefore, it is possible to prevent the durability of the intake communication passage from being deteriorated due to the twist, and to prevent the intake system or its engine body side connecting portion from being damaged due to stress concentration due to the displacement of the intake communication passage in the longitudinal direction. Further, since the shutter valve is provided in the highly rigid communication passage portion made of a metal material, stable operation without prying or the like is secured.

[0007] Further, the compressor discharge side of the primary turbocharger, which operates in the entire supercharging region from low to high revolutions of the engine and has large displacement in the twisting direction and the pulling direction due to thermal expansion of the turbine, is connected to the intake pipe connecting portion. Since the parts up to are made of elastic material, the displacement absorption by the elastic material becomes more effective. Also, since the operating area covers the entire area, the distance to the intake pipe connection part should be shortened to reduce the passage resistance. By using an elastic material for the primary side passage portion, which is advantageous in, the elastic material portion from the passage portion to the intake pipe connecting portion can be formed compactly.

Further, by forming the compressor discharge side of the turbocharger on the front side of the vehicle with an elastic material, it is possible to prevent heat damage to the elastic material due to running wind.

[0009]

1 is a schematic front view of a rotary engine showing an embodiment of the present invention, FIG. 2 is a schematic view taken in the direction of arrow A in FIG. 1, and FIG. 3 is a schematic view taken in the direction of arrow B in FIG. In the figure, reference numeral 1 denotes an engine body of a two-rotor rotary engine in which an intake manifold 2 and an exhaust manifold 3 are connected to the same side surface.

The intake manifold 2 has a total of four intake passages 2a, 2b, 2c, 2d, one on the primary side and one on the secondary side, for one cylinder. One end of the intake manifold 2 is connected to the upper side surface of the engine body 1. The other end side is curved upward and is connected to the extension manifold 4 arranged horizontally. Then, the four intake passages 2a are gathered in the extension manifold 4, and the inlet of the gathering portion is connected to an intake pipe 6 leading to an intercooler (not shown) via a throttle body 5. Further, the exhaust manifold 3 is connected to the side surface of the engine body 1 below the intake manifold 2 to form two exhaust passages, one for each cylinder.

In this engine, a primary turbo supercharger 7 which operates in a whole range from low rotation to high rotation in a predetermined supercharging range of the engine and a secondary turbocharger 8 which operates only in a high rotation range are turbine casings. A sequential twin turbocharger 10 in which 9 parts are integrated and unitized is provided. The primary turbocharger 7 is composed of a primary turbine 11 and a primary compressor 12, and the secondary turbocharger 8 is composed of a secondary turbine 13 and a secondary compressor 14. Then, the primary turbo supercharger 7 and the secondary turbo supercharger 8 are arranged so that the turbines 11 and 13 are adjacent to each other and the compressors 12 and 14 are located on both sides.
And are arranged in series in the axial direction of the turbine.

FIG. 4 is a schematic structural diagram of the sequential twin turbocharger 10. In this sequential twin turbocharger 10, the turbines 11 and 13 are arranged next to each other in series, so that the blade directions of the primary turbine 11 and the secondary turbine 13 are opposite to each other in the assembled state, and the primary compressor 12 and the secondary compressor 14 have the opposite blade directions. The blade direction is opposite. The primary turbine 11 and the primary compressor 12 are connected by the primary turbine shaft 15, and the secondary turbine 13 and the secondary compressor 14 are connected by the secondary turbine shaft 16. Then, for both turbines 11 and 13, arrows A and B in FIG.
As shown by the arrow, the exhaust gas flows in from the tangential direction, and the exhaust gas that drives the turbines 11 and 13 merges to form an arrow C.
It flows out from the center as shown in. Both compressors 12 and 14 are rotationally driven via turbine shafts 15 and 16, respectively, and intake air is sucked in from the turbine axial direction as shown by arrows D and E in FIG. 4, and tangentially as shown by arrows F and G. Discharge upwards.

The above-mentioned sequential twin turbocharger 1
No. 0 is connected to the exhaust manifold 3 so that the inlet of the primary turbine 11 communicates with the exhaust passage of one cylinder and the inlet of the secondary turbine 13 communicates with the exhaust passage of the other cylinder. Sequential twin turbocharger 1
When 0 is set in the vehicle, the primary turbocharger 7 is located in front of the vehicle.

Above the sequential twin turbocharger 10, a collecting pipe 17 made of an elastic material (heat resistant resin or the like).
Are arranged in the turbine axial direction, one end of which is connected to the discharge port of the primary compressor 12 and the other end of which is connected to the discharge port of the secondary compressor 14 and connected to the communication pipe 18 made of a metal material extending in the turbine axial direction. ing. An intake pipe 19 upstream of the intercooler is connected to the collecting pipe 17. The collecting pipe 17 and the communication pipe 18 thus form an intake communication passage that connects the discharge ports of both compressors 12 and 14 and connects to the intake pipe 19 upstream of the intercooler. In addition, the communication pipe 1 formed of a metal material
A shutter valve 20 is provided in the vicinity of the connecting portion with the collecting pipe 17.
Is installed. The shutter valve 20 is controlled to open in a predetermined high rotation range of the engine.

A fuel injection valve 21 is installed above the engine body 1 so as to inject fuel directly into the working chamber of the intake stroke. Further, a water jacket 22 is provided on the curved portion of the intake manifold 2 on the outer peripheral side facing the sequential turbocharger 10. The water jacket 22 is for warming the intake manifold 2 with engine cooling water to accelerate vaporization and atomization of fuel when the engine is warmed up, and the primary side intake passage of each cylinder located in the center of the intake manifold 2. It is formed so as to cover the portions 2a and 2c. In order to prevent heat damage from the sequential turbocharger 10, the water jacket 22 is expanded from the primary side intake passages 2a and 2c to the secondary side intake passages 2b and 2d. Has become.

The sequential turbocharger 10 has a turbine between the primary turbine 11 and the primary compressor 12 (center housing portion) and between the secondary turbine 13 and the secondary compressor 14 (center housing portion). Cooling water passages 23, 24 are formed so as to surround the shafts 15, 16. Then, in each of the cooling water passages 23, 24, cooling water is introduced horizontally from the inside, that is, the side close to the engine body 1 at the turbine shaft height, and bypasses around the turbine shaft to be horizontally at the same height position as the inlet side. An inlet side connector 25 and an outlet side connector 26 are provided so as to output the cooling water to the outside in the direction.

A water pipe 27 is connected vertically downward to each inlet side connector 25 on the primary side and the secondary side so as to form a cooling water passage from a water pump (not shown), and a vertical upward direction is connected to each outlet side connector 26. Is connected to the water pipe 28. The water pipe 28 on the outlet side is bent and connected to the central portion of the water jacket 22 of the intake manifold 2. Also,
A return water pipe 29 is connected to an upper end of one end of the water jacket 22. By thus circulating the cooling water discharged from the cooling water passages 23, 24 of the sequential turbocharger 10 to the water jacket 22 on the outer circumference of the intake manifold, the intake manifold 2 can be effectively warmed by the high-temperature cooling water. Achieves good vaporization and atomization during cold weather. In particular, the cooling water passages 23 and 24 of the supercharger 10 are configured so as to send the cooling water from the horizontal direction, bypass it, and send it out from the opposite side in the horizontal direction. Increased
The amount of heat received increases and the effect of improving vaporization and atomization increases.

Although not described in the above embodiment,
Since the displacement due to thermal expansion extends to the suction port sides of both compressors, the intake pipes upstream of the suction ports of the primary compressor and the secondary compressor may be formed entirely of resin, which is an elastic material.

Although the embodiment applied to the rotary engine has been described above, the present invention can be applied to other engines. It can also be applied to a supercharged engine having two superchargers other than the sequential turbo type.

[0020]

According to the present invention, two turbochargers are arranged in series with the turbines next to each other, and the intake passages connecting the discharge ports of both compressors to the intake pipe are connected to the turbine shaft. In the one arranged in the direction, the thermal expansion of both turbine parts is achieved by forming the intake pipe connection part of the communication passage and the part from the compressor discharge side of one turbocharger to the intake pipe connection part with an elastic material. The twisting of the intake communication passage due to the opposite direction and the longitudinal displacement of the intake communication passage due to the compressors on both sides bending with respect to the turbine shaft during thermal expansion are absorbed to improve the durability of the intake communication passage. It is possible to prevent deterioration and damage to the other intake system or its connecting portion with the engine body. By providing the shutter valve in a portion formed of a metal material, it is possible to ensure stable operation without twisting.

Further, when the primary turbocharger that operates in the entire supercharging range from low speed to high speed and the secondary turbocharger that operates only in the high speed range are arranged in series, the primary turbocharger By forming the part from the compressor discharge side of the feeder to the intake pipe connection part with an elastic material, the displacement absorption effect on the primary side, which has severe conditions due to the wide operating range, is enhanced and the primary side passage to the intake pipe connection part The distance between the parts can be shortened to reduce the passage resistance in the entire area.

Further, by using the elastic material on the compressor discharge side of the turbocharger on the front side of the vehicle, the elastic material can be cooled by the traveling wind to prevent heat damage.

[Brief description of drawings]

FIG. 1 is a schematic front view of a rotary engine showing an embodiment of the present invention.

FIG. 2 is a schematic view taken along arrow A in FIG.

FIG. 3 is a schematic view taken along the arrow B in FIG.

FIG. 4 is a schematic structural diagram of a sequential twin turbocharger according to an embodiment of the present invention.

[Explanation of symbols]

 1 Engine Main Body 2 Intake Manifold 3 Exhaust Manifold 7 Primary Turbo Supercharger 8 Secondary Turbo Supercharger 11 Primary Turbine 12 Primary Compressor 13 Secondary Turbine 14 Secondary Compressor 15,16 Turbine Shaft 17 Assembly Pipe (Elastic Material) 18 Communication Pipe (Metal) Material) 20 Shutter valve

Claims (3)

[Claims] 1. A turbocharger for driving a turbine with exhaust gas and rotating a compressor via the turbine shaft by the turbine is arranged in series in the turbine axial direction so that the turbines are adjacent to each other. In an intake device for an engine with a turbocharger in which an intake communication passage that connects the compressor discharge port of the feeder and connects to the intake pipe is arranged in the turbo axial direction, an intake pipe connection part of the communication passage and one turbo supercharge The portion from the compressor discharge side of the machine to the intake pipe connecting portion is made of an elastic material, and the portion from the compressor discharge side of the other turbocharger to the intake pipe connecting portion is made of a metal material. An intake device for an engine with a turbocharger, characterized in that a shutter valve is provided in the communication passage portion formed in (1). 2. The one turbocharger is a primary turbocharger that operates in the entire supercharging range of the engine from low speed to high speed, and the other turbocharger is in a predetermined high speed range. The turbocharger engine intake system according to claim 1, wherein the intake system is a secondary turbocharger that is operated only in. 3. The intake system for an engine with a turbocharger according to claim 1, wherein the one turbocharger is a turbocharger on the front side of the vehicle.