JP5845627B2 - Turbocharged internal combustion engine - Google Patents

Description

  The present invention relates to an internal combustion engine including a turbocharger having a turbine that introduces an exhaust flow from an exhaust manifold and rotates a turbine wheel, and a compressor that compresses intake air by the rotational force of the turbine wheel.

A configuration is known in which cooling water is supplied to members constituting an exhaust system of an internal combustion engine with a turbocharger to prevent thermal damage of each member (see, for example, Patent Documents 1 to 4).
In Patent Document 1, cooling water is supplied to an exhaust cooling adapter, a turbo housing, and a waste gate valve, respectively, to prevent thermal damage of each member.

In Patent Document 2, the exhaust passage for supplying exhaust gas to the switching valve of the waste gate valve actuator is cooled with cooling water to prevent heat damage to the switching valve.
In Patent Document 3, cooling water is introduced from a cylinder head into a turbine housing to prevent thermal damage to the turbine.

In Patent Document 4, a turbine is built in a cylinder head, and the turbine is cooled by cooling water flowing in the cylinder head, thereby suppressing the temperature rise of the compressor.
As described above, a configuration is known in which a heat damage is prevented by disposing the actuator of the waste gate valve in a place in a lower temperature atmosphere than the other place instead of cooling with cooling water (for example, Patent Document 5). reference).

Japanese Utility Model Publication No. 64-15718 (pages 14-17, FIG. 3) Japanese Unexamined Patent Publication No. 62-131922 (page 4, FIG. 4) JP 2008-190503 A (pages 6-9, FIGS. 3-4) JP 2002-303145 A (pages 4-5, FIGS. 2-3) Japanese Patent Laid-Open No. 63-21328 (page 4, FIGS. 1-2)

  However, in the configuration of Patent Document 1, piping such as cooling water piping and cooling water recirculation piping for cooling the waste gate valve on which the actuator is mounted is arranged in a complicated manner, so that the internal combustion engine is increased in size and production efficiency is increased. May decrease.

In Patent Document 2, the actuator is not cooled and heat damage cannot be prevented.
In Patent Documents 3 and 4, since the actuator is arranged in the cylinder head, the configuration of the cylinder head may be enlarged or complicated, and production efficiency may be reduced.

In Patent Document 5, since the actuator is not actively cooled, there is a fear that the heat damage prevention is insufficient.
An object of the present invention is to provide an internal combustion engine with a turbocharger that can sufficiently prevent thermal damage to an actuator that controls a turbocharger such as an actuator for a waste gate valve with a simple configuration.

In the following, means for achieving the above-mentioned purpose, and its operation and effect are described.
An internal combustion engine with a turbocharger according to claim 1 and 2 includes a turbocharger having a turbine that introduces an exhaust flow from an exhaust manifold and rotates a turbine wheel, and a compressor that compresses intake air by the rotational force of the turbine wheel. A cooling water flow path is formed in the wall portion from the exhaust manifold to the turbine housing, and an actuator for controlling the turbocharger is attached to the outer surface side of the wall portion where the cooling water flow path is formed. It is characterized by that.

  In this way, the cooling water flow path is formed in the wall portion from the exhaust manifold to the turbine housing, so that the actuator has an outer surface of the wall portion on which the cooling water flow path is formed, in contrast to the configuration in which the exhaust system is cooled. Is attached to the side.

  Thus, since the actuator is attached to the wall part cooled by the cooling water, it is not heated by the heat transfer from the exhaust. Therefore, it is not necessary to supply cooling water to the actuator by piping. Moreover, it is only necessary to attach to the outer surface side of the corresponding wall portion.

In this way, the heat damage of the actuator that controls the turbocharger can be sufficiently prevented with a simple configuration.
In the turbocharged internal combustion engine according to claim 1 , further, a part or all of the housing of the actuator is integrally formed on an outer surface of a wall portion where the cooling water flow path is formed. Features.

  As described above, a part or all of the housing of the actuator is integrally formed on the outer surface of the wall portion cooled by the cooling water, so that the number of parts such as fastening parts is reduced and the structure is further simplified. In addition, the heat transfer is improved and the cooling effect of the actuator is enhanced.

In the turbocharged internal combustion engine according to claim 2 , the base portion of the actuator is further integrally formed on an outer surface of a wall portion where the cooling water flow path is formed. To do.

  As described above, since the base portion of the actuator is integrally formed on the outer surface of the wall portion that is cooled by the cooling water, the number of parts such as fastening parts is reduced and the configuration is further simplified. Moreover, the heat dissipation from the actuator to the cooling water flow path side is improved by passing through the base portion, and the cooling effect of the actuator is enhanced.

A turbocharged internal combustion engine according to a third aspect is characterized in that in the internal combustion engine with a turbocharger according to the first or second aspect , the exhaust manifold and the turbine housing are integrally formed.

  The exhaust manifold and the turbine housing may be integrally formed. If comprised in this way, the seal | sticker of the connection part of an exhaust manifold and a turbine housing will become unnecessary, and the reliability with respect to exhaust leakage will also improve.

The turbocharged internal combustion engine according to claim 4 , wherein the actuator is configured to increase a supercharging pressure by bypassing an exhaust flow with respect to the turbine wheel according to any one of claims 1 to 3. It is an actuator that drives a waste gate valve that is adjusted according to the operating state of the internal combustion engine.

  An actuator that drives a waste gate valve can be used. By preventing the heat damage of the actuator, highly accurate supercharging pressure control can be continued over a long period of time.

The turbocharged internal combustion engine according to claim 5 , wherein in the turbocharged internal combustion engine according to any one of claims 1 to 3 , the actuator is configured to control an exhaust flow sprayed on a turbine wheel by adjusting an angle of a nozzle vane. characterized in that the boost pressure in Rukoto changing the flow rate as an actuator to adjust in accordance with the engine operating condition.

  An actuator that adjusts the angle of the nozzle vane can be used. By preventing the heat damage of the actuator, highly accurate supercharging pressure control can be continued over a long period of time.

A turbocharged internal combustion engine according to claim 6 , wherein the actuator is an electric actuator in the turbocharged internal combustion engine according to any one of claims 1 to 5 .

  In particular, electric actuators are more susceptible to thermal degradation than mechanical actuators. However, as described above, high temperatures can be sufficiently suppressed, so that electric actuators can sufficiently prevent thermal damage with a simple configuration. be able to.

FIG. 2 is a schematic configuration diagram of an exhaust system in the internal combustion engine of the first embodiment. FIG. 3 is a perspective view of an integrated body of an exhaust manifold and a turbine housing in the first embodiment. FIG. 3 is a cross-sectional view of a main part of the exhaust system in the internal combustion engine of the first embodiment. FIG. 6 is a cross-sectional view of a main part of an exhaust system in the internal combustion engine of the second embodiment. FIG. 4 is a cross-sectional view of a main part of an exhaust system in an internal combustion engine according to a third embodiment. FIG. 7 is a cross-sectional view of a main part of an exhaust system in the internal combustion engine of the fourth embodiment.

[Embodiment 1]
<Configuration> FIG. 1 shows an exhaust system of an internal combustion engine 2 to which the above-described invention is applied. The internal combustion engine 2 is an in-line four-cylinder internal combustion engine, and an exhaust manifold 8 is connected to the exhaust port 6 side of the cylinder head 4. The exhaust manifold 8 is integrally formed with the turbine housing 12 of the turbocharger 10. FIG. 2 shows an integrated body 14 of the exhaust manifold 8 and the turbine housing 12 integrally formed by casting.

  1 and 2, only the turbine housing 12 is shown for the turbocharger 10. In practice, the turbocharger 10 is combined with a compressor with a turbine wheel disposed inside the turbine housing 12.

The turbine wheel disposed in the turbocharger 10 is rotated by the exhaust flow flowing from the exhaust passage 8 a in the exhaust manifold 8.
The exhaust flow obtained by rotating the turbine wheel is discharged to the exhaust pipe connected to the turbine flange 12a. As a result, the exhaust flow is discharged from the turbocharger 10 and flows to the exhaust purification catalyst side.

  A compressor housing connection portion 12b is formed on the side opposite to the turbine flange 12a, and the compressor housing is connected to the compressor housing connection portion 12b. A compressor blade that rotates integrally with the turbine wheel is disposed in the compressor housing, and compresses the intake air sucked through the air cleaner. The compressed intake air is supplied to the combustion chamber 18 of each cylinder from the intake port 16 via an intercooler and a throttle valve and used for combustion.

  Here, the exhaust manifold 8 is of a water cooling type, and as shown in FIG. 3, a cooling water flow path 8b is provided around the exhaust passage 8a. The turbine housing 12 formed integrally with the exhaust manifold 8 is also provided with a cooling water flow path 12c for exhaust cooling. The cooling water flow path 8b on the exhaust manifold 8 side and the cooling water flow path 12c on the turbine housing 12 side are formed continuously.

  Cooling water obtained by diverting a part of the cooling water supplied to the cylinder block or cylinder head 4 or cooling water after cooling the cylinder block or cylinder head 4 is supplied from the inlet 8c on the exhaust manifold 8 side. The This cooling water flows through the cooling water flow path 8b on the exhaust manifold 8 side and flows into the cooling water flow path 12c on the turbine housing 12 side. And it discharges | emits from the discharge port 12d provided in the turbine housing 12 side. Since the cooling water discharged from the discharge port 12d has a high temperature, the water is cooled by exchanging heat with the radiator, and then circulated again by the water pump.

  An actuator 20 is attached to the outer surface of the integrated body 14 of the exhaust manifold 8 and the turbine housing 12. The actuator 20 is provided to open and close the waste gate valve 22.

  The internal combustion engine 2 is provided with an electronic circuit for controlling the actuator 20, and the waste gate valve 22 is controlled so that the supercharging pressure by the compressor of the turbocharger 10 does not become excessive according to the operating state of the internal combustion engine 2. The open / close state is adjusted.

  The actuator 20 is mainly composed of an electric motor here, and rotates the control shaft 20a via a gear mechanism. The control shaft 20a is connected to the waste gate valve 22 in the turbine housing 12 through the wall portion 14a of the integral body 14, and rotates around the axis to open and close the waste gate valve 22.

  When the waste gate valve 22 is closed, the exhaust flow supplied from the exhaust manifold 8 directly rotates the turbine wheel, so that the boost pressure can be sufficiently increased by the compressor. When the waste gate valve 22 is opened, the exhaust flow supplied from the exhaust manifold 8 passes through the waste gate valve 22 and the exhaust flow bypasses the turbine wheel, so that the supercharging pressure can be suppressed.

As shown in FIG. 3, the outer surface of the integrated body 14 on which the actuator 20 is disposed corresponds to the outer surface of the wall portion 14 a of the exhaust manifold 8 where the cooling water flow path 8 b is formed.
<Operation> Since the cooling water flow path 8b exists between the actuator 20 and the exhaust passage 8a, heat transfer from the exhaust to the actuator 20 is prevented even when high-temperature exhaust flows through the exhaust passage 8a. Since the actuator 20 is also cooled by the cooling water, the actuator 20 does not increase in temperature.
<Effect> (1) As described above, the cooling water flow paths 8b and 12c are formed in the wall portion 14a from the exhaust manifold 8 to the turbine housing 12. The actuator 20 mainly composed of an electric motor is attached to the outer surface side of the wall portion 14a where the cooling water flow path 8b on the exhaust manifold 8 side is formed.

  Since the wall portion 14a is cooled by the cooling water in the cooling water flow path 8b, the actuator 20 is not heated by heat transfer from the exhaust flow in the exhaust passage 8a. For this reason, it is not necessary to supply cooling water to the actuator 20 by piping. Moreover, it is only necessary to attach to the outer surface side of the wall portion 14a. For this reason, the mounting configuration is also simple.

Thus, the heat damage of the actuator 20 that drives the waste gate valve 22 can be sufficiently prevented with a simple configuration.
(2) In particular, the actuator 20 is an electric actuator. Here, an electric motor is mainly used. Such an electric actuator is more susceptible to thermal degradation than a mechanical actuator such as a diaphragm. However, the above-described configuration sufficiently suppresses the increase in temperature, and even a simple configuration can provide sufficient heat damage. Can be prevented. Thus, highly accurate supercharging pressure control can be continued over a long period of time.

  (3) The exhaust manifold 8 and the turbine housing 12 are integrally formed to be an integrated object 14. By using the integrated body 14 in this way, it is not necessary to seal the connection portion between the exhaust manifold 8 and the turbine housing 12, and the reliability against exhaust leakage is improved.

[Embodiment 2]
<Configuration> FIG. 4 shows the configuration of the exhaust system in the internal combustion engine 102 of the present embodiment. Here, the actuator 120 attached to the outer surface side of the integral member 114 of the exhaust manifold 108 and the turbine housing 112 has a base portion 120a integrally formed on the outer surface of the wall portion 114a of the integral member 114 by casting. The actuator 120 is mounted on the base portion 120a so as to be covered with the resin cover 120b. Other configurations are the same as those of the first embodiment.
<Operation> Since the base 120a of the actuator 120 is integrally formed on the outer surface side of the wall 114a, the number of parts such as fastening parts is reduced and the configuration is further simplified. Moreover, heat dissipation from the actuator 120 toward the cooling water flow path 108b is also improved by using the base 120a.
<Effect> (1) While the effect of the first embodiment is produced, the configuration is further simplified, and the cooling effect of the actuator 120 by the cooling water flow path 108b in the wall 114a is enhanced.

  (2) In order to cover the base 120a that is cooled by the cooling water in the cooling water flow path 108b, high heat resistance is not required, so the internal actuator 120 is covered with a resin cover 120b that is not made of metal. ing. For this reason, it can contribute to the weight reduction and cost reduction of a material.

[Embodiment 3]
<Configuration> FIG. 5 shows the configuration of the exhaust system in the internal combustion engine 202 of the present embodiment. Here, the actuator 220 attached to the outer surface side of the integrated member 214 of the exhaust manifold 208 and the turbine housing 212 is attached not to the exhaust manifold 208 side but to the outer surface side of the integrated member 214 on the turbine housing 212 side.

A cooling water flow path 212c is formed in the wall 214a where the actuator 220 is attached. Other configurations are the same as those of the first embodiment.
<Operation> Even when the actuator 220 is arranged on the turbine housing 212 side of the one-piece 214 as described above, the cooling water flow path 212c exists between the actuator 220 and the exhaust passage 212a. Yes. Therefore, due to the cooling action of the cooling water in the cooling water passage 212c, the actuator 220 does not reach a high temperature even when high-temperature exhaust flows in the exhaust passage 212a.
<Effect> (1) In addition to the effects of the first embodiment, the actuator 220 can be disposed near the waste gate valve 222, so that the control shaft 220a can be shortened and the internal combustion engine 202 can be reduced in weight. Furthermore, less electric energy is consumed in the actuator 220 for driving the control shaft 220a.

[Embodiment 4]
<Configuration> FIG. 6 shows the configuration of the exhaust system in the internal combustion engine 302 of the present embodiment.
Here, on the turbine housing 312 side, a waste gate valve is not provided, but a nozzle vane angle adjusting mechanism 322 is provided in the turbine instead.

  The turbine arranged in the turbine housing 312 is provided with a rotatable nozzle vane, and the nozzle vane angle adjusting mechanism 322 rotates the nozzle vane to adjust its direction.

  The actuator 320, which is an electric motor, adjusts the nozzle vane angle by driving the nozzle vane angle adjusting mechanism 322 by the axial rotation or axial movement of the control shaft 320a.

  By adjusting the angle of the nozzle vanes, the exhaust flow for operating the turbine can be adjusted, and a reduction in the amount of intake air supplied from the turbocharger 310 to the internal combustion engine 302 due to a change in exhaust pressure can be suppressed.

As in the first embodiment, the actuator 320 is attached to the outer surface side of the wall portion 314a in which the cooling water flow path 308b on the exhaust manifold 308 side is formed in the integrated body 314 of the exhaust manifold 308 and the turbine housing 312. ing. Other configurations are the same as those in the first embodiment.
<Operation> As described above, when the actuator 320 for driving the nozzle vane angle adjusting mechanism 322 is used as the turbocharger control actuator, the same operation as in the first embodiment is produced.
<Effect> (1) The effect similar to that of the first embodiment is also produced in the actuator 320 for the nozzle vane angle adjusting mechanism 322.

[Other embodiments]
In the actuator 120 of the second embodiment, the base portion 120a is integrally formed with the integrated body 114 of the exhaust manifold 108 and the turbine housing 112, but part or all of the housing of the actuator 120 is also integrated. It may be integrally formed with 114. The same applies to other embodiments.

  As for the actuator 220 of the third embodiment, the base portion may be integrally formed with the integrated body 214 as in the second embodiment, or a part or all of the housing of the actuator 220 is integrated with the integrated body 214. It may be molded. The same applies to the actuator 320 that drives the nozzle vane angle adjusting mechanism 322 in the fourth embodiment.

  In each of the above embodiments, the actuator that drives the waste gate valve and the nozzle vane angle adjustment mechanism is an electric motor, but an electric actuator such as a solenoid may be used.

Further, a mechanical actuator using a diaphragm or the like may be used. Thus, even if it is a mechanical type, the malfunctioning by heat damage can be prevented.
In each of the above embodiments, the exhaust manifold and the turbine housing are integrally formed. However, the exhaust manifold and the turbine housing may be formed separately and mechanically connected.

  DESCRIPTION OF SYMBOLS 2 ... Internal combustion engine, 4 ... Cylinder head, 6 ... Exhaust port, 8 ... Exhaust manifold, 8a ... Exhaust passage, 8b ... Cooling water flow path, 8c ... Inlet, 10 ... Turbocharger, 12 ... Turbine housing, 12a ... Turbine flange , 12b ... compressor housing connection part, 12c ... cooling water flow path, 12d ... discharge port, 14 ... integral, 14a ... wall part, 16 ... intake port, 18 ... combustion chamber, 20 ... actuator, 20a ... control shaft, 22 ... Wastegate valve, 102 ... Internal combustion engine, 108 ... Exhaust manifold, 108b ... Cooling water flow path, 112 ... Turbine housing, 114 ... Monolith, 114a ... Wall, 120 ... Actuator, 120a ... Base, 120b ... Resin cover 202 ... Internal combustion engine 208 ... Exhaust manifold 212 ... Turbine Using, 212a ... exhaust passage, 212c ... cooling water flow path, 214 ... integral, 214a ... wall, 220 ... actuator, 220a ... control shaft, 222 ... wastegate valve, 302 ... internal combustion engine, 308 ... exhaust manifold, 308b ... Cooling water flow path, 310 ... turbocharger, 312 ... turbine housing, 314 ... integral, 314a ... wall, 320 ... actuator, 320a ... control shaft, 322 ... nozzle vane angle adjustment mechanism.

Claims (6)

An internal combustion engine including a turbocharger having a turbine that rotates an turbine flow by introducing an exhaust flow from an exhaust manifold, and a compressor that compresses intake air by the rotational force of the turbine wheel,
A cooling water passage is formed in the wall portion from the exhaust manifold to the turbine housing, and an actuator for controlling the turbocharger is attached to the outer surface side of the wall portion where the cooling water passage is formed ,
An internal combustion engine with a turbocharger , wherein a part or all of the housing of the actuator is integrally formed on an outer surface of a wall portion where the cooling water flow path is formed . An internal combustion engine including a turbocharger having a turbine that rotates an turbine flow by introducing an exhaust flow from an exhaust manifold, and a compressor that compresses intake air by the rotational force of the turbine wheel,
A cooling water passage is formed in the wall portion from the exhaust manifold to the turbine housing, and an actuator for controlling the turbocharger is attached to the outer surface side of the wall portion where the cooling water passage is formed ,
An internal combustion engine with a turbocharger , wherein a base portion of the actuator is integrally formed on an outer surface of a wall portion where the cooling water flow path is formed . The internal combustion engine with a turbocharger according to claim 1 or 2 , wherein the exhaust manifold and the turbine housing are integrally formed. The turbocharged internal combustion engine according to any one of claims 1 to 3 , wherein the actuator includes a waste gate valve that adjusts a supercharging pressure according to an operating state of the internal combustion engine by bypassing an exhaust flow with respect to the turbine wheel. An internal combustion engine with a turbocharger, characterized by being an actuator for driving. In turbocharged internal combustion engine according to any one of claims 1 to 3, wherein the actuator is an internal combustion boost pressure in Rukoto changing the flow velocity of the exhaust stream blown to the turbine wheel by angle adjustment of the nozzle vanes An internal combustion engine with a turbocharger, characterized in that the actuator is adjusted according to the engine operating state. The internal combustion engine with a turbocharger according to any one of claims 1 to 5 , wherein the actuator is an electric actuator.

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