JP2009270508A - Internal combustion engine with intercooler - Google Patents

Abstract

Provided is an internal combustion engine with an intercooler that can be mounted on a vehicle without sacrificing the cooling performance of recirculated gas as well as ensuring the intake charging efficiency as an on-vehicle internal combustion engine.
In this internal combustion engine, an intercooler 24 is provided integrally with an intake manifold 23 that also serves as a surge tank, and an intake system side end 51B of an EGR passage 51 that constitutes an exhaust gas recirculation (EGR) device 5 is provided. This is connected to the surge tank portion of the intake manifold 23 upstream of the intercooler 24. That is, the intake air compressed (supercharged) by the turbocharger 4 and the recirculation gas circulated through the EGR passage 51 are cooled through the single intercooler 24.
[Selection] Figure 1

Description

  The present invention relates to an intercooler-equipped internal combustion engine including an intercooler that cools supercharged intake air and sends it to an engine combustion chamber.

  As is well known, in an in-vehicle internal combustion engine equipped with a turbocharger such as a turbocharger, the supercharged intake air is cooled by the intercooler in order to increase the charging efficiency of the intake air. Many internal combustion engines are fed into the engine combustion chamber. That is, in such an internal combustion engine, even if the temperature of the intake air rises due to the compression of the supercharger and the density decreases, the density is increased by cooling by the intercooler, and the engine combustion chamber has high charging efficiency. Will be supplied to.

  On the other hand, in-vehicle internal combustion engines are often provided with a device that recirculates a part of exhaust gas to intake air, that is, an exhaust recirculation device (EGR (Exhaust Gas Recirculation) device). Exhaust gas (recirculation gas) recirculated by such an EGR device acts as an intake diluent, lowers the peak combustion temperature of the internal combustion engine, and contributes effectively to reducing NOx (nitrogen oxide) production. .

  And as an internal combustion engine provided with both a supercharger and an EGR device as described above, for example, an internal combustion engine described in Patent Document 1 is known. FIG. 3 shows an outline of an engine structure that has been generally adopted as such an internal combustion engine, including the engine described in this document.

As shown in FIG. 3, in an internal combustion engine (in this example, an in-line four-cylinder internal combustion engine) provided with a supercharger and an EGR device, intake air is introduced into the combustion chambers of the cylinders # 1 to # 4 of the engine body 101. An intake passage 120 for supplying and an exhaust passage 130 for discharging exhaust from these combustion chambers are connected to the engine body 101, respectively. Between the intake passage 120 and the exhaust passage 130, the turbine 141 driven by the exhaust gas flowing through the exhaust passage 130 and the intake air supplied to the intake passage 120 by being drivingly connected to the turbine 141 are compressed (supercharged). A turbocharger 140 having a compressor 143 is provided. For this reason, the intake air from which dust or the like has been removed by the air cleaner 121 in the intake passage 120 is compressed by the compressor 143 and the temperature thereof temporarily rises, but the intercooler 122 provided downstream of the compressor 143 in the intake passage 120. By cooling through the air density, the air density is increased. Then, the intake air whose air density is increased in this way is adjusted in flow rate by a throttle valve provided in the throttle body 123 to reach an intake manifold 124 that also serves as a surge tank, and is supplied from the intake manifold 124 to each cylinder of the engine body 101. Is done. On the other hand, the exhaust discharged from each cylinder of the engine body 101 reaches the catalytic converter 132 via the exhaust manifold 131 and the turbine 141 provided in the exhaust passage 130, where harmful components are removed (purified) to the outside. To be discharged. In addition, a part of the exhaust gas at this time reaches the EGR cooler 152 from the exhaust passage 130 (exhaust manifold 131) through the EGR passage 150 and is cooled as necessary, and the flow rate is adjusted by the EGR valve 153. Then, the air is recirculated to the intake passage 120 (intake manifold 124).
JP 2001-152861 A

In particular, in an internal combustion engine equipped with a supercharger, it is as described above that an intake air charging efficiency can be greatly increased by providing an intercooler in the intake passage. By providing the EGR cooler, the recirculation gas is cooled, and the effect of reducing the combustion temperature is further enhanced. However, in this case, as is clear from FIG. 3, since two cooling devices such as the intercooler 122 and the EGR cooler 152 are required, the internal combustion engine itself is inevitably increased in size. The ability to be greatly restricted.

  The present invention has been made in view of such circumstances, and its purpose is not only to ensure the intake charging efficiency as an in-vehicle internal combustion engine, but also to the vehicle without sacrificing the cooling performance of the recirculated gas. An object of the present invention is to provide an internal combustion engine with an intercooler capable of improving the mountability.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
In order to solve the above-described problem, an invention according to claim 1 is an internal combustion engine with an intercooler that supplies intake air compressed by a supercharger to an engine combustion chamber by cooling with an intercooler, wherein the engine combustion An exhaust gas recirculation device that recirculates a part of the exhaust gas discharged from the chamber to the exhaust air passage to the intake air system via the exhaust air circulation passage, and the intake system side end of the exhaust air circulation passage is a supercharger And the intercooler is connected.

  According to such a configuration, the recirculation gas by the exhaust gas recirculation (EGR) device provided for the purpose of reducing the NOx generation amount by lowering the combustion temperature is also cooled in the form of sharing the intercooler. It becomes possible. As a result, conventionally, an EGR cooler provided in the exhaust gas recirculation passage for the purpose of cooling only the recirculation gas is unnecessary, or it can be a small-sized one that requires a low cooling capacity. As the EGR cooler is reduced and downsized, the downsizing of the EGR cooler is promoted, and the mountability on the vehicle is naturally improved.

  According to a second aspect of the present invention, in the internal combustion engine with an intercooler according to the first aspect, the intercooler is provided integrally with an intake manifold that also serves as a surge tank of the engine, and the exhaust gas recirculation passage The gist of the present invention is that the end portion of the intake system is connected to the surge tank portion of the intake manifold.

  According to such a configuration, it is not necessary to separately provide an intercooler in the middle of the intake passage, etc., and the intercooler is integrated with the intake manifold that also serves as the surge tank, which is relatively large in size as an engine part. By being provided, the space utilization efficiency of the entire engine can be further enhanced. In addition, when the recirculation gas by the EGR device is circulated in the surge tank portion having a large volume, intake pulsation due to such recirculation of the recirculation gas is also preferably suppressed.

  According to a third aspect of the present invention, in the internal combustion engine with an intercooler according to the second aspect, a throttle body including a throttle valve in parallel with the exhaust gas recirculation passage is provided upstream of the surge tank of the intake manifold that also serves as the surge tank. The exhaust gas recirculation passage is provided with a valve (EGR valve) for adjusting the flow rate of the recirculation gas flowing in the passage.

According to such a configuration, even when the intercooler is shared by the supercharged intake air and the recirculated gas, the respective flow rates can be individually adjusted.
The gist of the invention according to claim 4 is the internal combustion engine with an intercooler according to claim 1, wherein the intercooler is provided upstream of a throttle body including a throttle valve.

  According to such a configuration, the configuration according to claim 1 can be realized by diverting the structure of the intake system that has been generally adopted as an internal combustion engine with an intercooler as it is.

The gist of the invention according to claim 5 is the internal combustion engine with an intercooler according to any one of claims 1 to 4, wherein the intercooler is a water-cooled cooler.
According to such a configuration, the cooling efficiency of the shared intercooler can be further increased.

(First embodiment)
A first embodiment of an internal combustion engine with an intercooler according to the present invention will be described below with reference to FIG. In the present embodiment, as an example, it is assumed that such an internal combustion engine is applied to an in-line four-cylinder internal combustion engine (vehicle-mounted internal combustion engine) as in the internal combustion engine illustrated in FIG.

  That is, as shown in FIG. 1, this internal combustion engine also includes an engine body 1 in which four cylinders, a first cylinder # 1 to a fourth cylinder # 4, are formed. The engine body 1 includes a cylinder head, a cylinder block, a piston, and the like. The cylinder head includes an intake passage 2 for supplying intake air to the combustion chambers of the cylinders # 1 to # 4, and each cylinder #. Exhaust passages 3 for exhausting exhaust from the combustion chambers 1 to # 4 are connected to each other. Further, between the intake passage 2 and the exhaust passage 3, there is provided a turbocharger 4 having a mechanism which is driven by exhaust flowing through the exhaust passage 3 and compresses intake air flowing through the intake passage 2.

  The turbocharger 4 includes a turbine 41 provided in the exhaust passage 3, a turbine housing 42 containing the turbine 41, a compressor 43 provided in the intake passage 2, a compressor housing 44 containing the compressor 43, and the turbine 41 and the compressor 43. It is a well-known supercharger provided with the rotary shaft 45 for connecting the shafts. That is, in the turbocharger 4, the exhaust gas flowing from the inlet of the turbine housing 42 in the exhaust passage 3 pushes the turbine blade to rotate the turbine 41, and the rotation of the turbine 41 is rotated via the rotary shaft 45 in the compressor of the intake passage 2. This is rotationally driven by being transmitted to 43. As a result, the intake air flowing into the compressor housing 44 in the intake passage 2 is compressed (supercharged) as the compressor 43 rotates. It is well known that the intake air thus compressed increases its density and temperature.

  On the other hand, in this internal combustion engine, the exhaust passage 3 includes an exhaust manifold 31 that collects exhaust from the combustion chambers of the cylinders # 1 to # 4 of the engine body 1 in one path, and a drive source of the turbocharger 4. In addition to the turbine 41, a catalytic converter 32 for removing (purifying) harmful components in the exhaust is provided.

  In the internal combustion engine, the intake passage 2 is supplied with the flow rate of intake air supplied to the combustion chambers of the cylinders # 1 to # 4, including the air cleaner 21 for removing dust from the intake air and the compressor 43. A throttle body 22 incorporating a throttle valve for adjustment is provided. Further, an intake manifold 23 is provided downstream of the throttle body 22 and serves as a surge tank and distributes the intake air metered by the throttle valve to the combustion chambers of the cylinders # 1 to # 4.

In this embodiment, the intake manifold 23 is integrally provided with a water-cooled intercooler 24, and the compressed and metered supply is cooled by the intercooler 24. That is, in this internal combustion engine, the air (intake air) taken into the intake passage 2 passes through the air cleaner 21 and is compressed by the compressor 43 to rise in temperature, but the flow rate is adjusted by the throttle valve of the throttle body 22. After being measured, it is cooled by an intercooler 24 provided integrally with the intake manifold 23. The intake air cooled by the intercooler 24 is supplied to each engine combustion chamber with its air density increased. As an engine part, the intercooler 24 is integrated with the intake manifold 23 that also functions as a relatively large surge tank, so that the intercooler that has been installed in the middle of the intake passage 2 is omitted. As a result, the space utilization efficiency of the internal combustion engine as a whole can be improved.

  On the other hand, the internal combustion engine is provided with an exhaust gas recirculation device (EGR device) 5 for circulating a part of the exhaust gas to the intake passage 2. In this embodiment, in particular, the exhaust system side end 51A of the EGR passage (exhaust recirculation passage) 51 connecting the exhaust passage 3 and the intake passage 2 of the EGR device 5 is connected to the exhaust manifold 31 and the same. The intake system side end 51B of the EGR passage 51 is connected to the surge tank portion of the intake manifold 23, respectively. In the present embodiment, the EGR passage 51 is provided with an EGR valve 53 for adjusting the flow rate of the exhaust gas (recirculation gas) to be recirculated to the intake passage 2, but is similar to the internal combustion engine illustrated in FIG. The EGR cooler (152) is not provided and is shared by the intercooler 24 provided integrally with the intake manifold 23. As described above, such an EGR device 5 is effective in circulating the recirculation gas that lowers the peak combustion temperature of the internal combustion engine and reduces the NOx generation amount to the intake system. The cooler for cooling the recirculation gas is shared by the intercooler 24 in this way. As a result, the EGR cooler can be reduced from the EGR device 5, and the mountability of the internal combustion engine on the vehicle is improved accordingly.

As described above, according to the internal combustion engine with an intercooler of the present embodiment, the effects listed below can be obtained.
(1) The recirculated gas by the exhaust gas recirculation (EGR) device 5 provided for the purpose of reducing the NOx generation amount by lowering the peak combustion temperature of the internal combustion engine is cooled in the form of sharing the intercooler 24. . As a result, the EGR cooler provided in the exhaust gas recirculation passage can be made unnecessary for the purpose of cooling only the recirculation gas in the related art, and the in-vehicle internal combustion engine can be reduced in size as the EGR cooler is reduced or reduced in size. Will be promoted, and the mountability to the vehicle will naturally be improved.

  (2) It is not necessary to separately provide an intercooler in the middle of the intake passage 2, and the intercooler 24 is provided integrally with the intake manifold 23 that also serves as the surge tank having a relatively large physique as an engine part. As a result, the space utilization efficiency of the entire engine can be further improved. In addition, when the recirculation gas by the EGR device 5 is circulated through the surge tank portion having a large volume, intake pulsation due to such recirculation of the recirculation gas is also preferably suppressed.

  (3) Since the intake body 2 is provided with a throttle body 22 containing a throttle valve and the like, and the EGR passage 51 is separately provided with an EGR valve 53, an intercooler is provided with supercharged intake air and recirculated gas. Even when 24 is shared, each flow rate can be metered separately.

(4) Since the intercooler 24 is a water-cooled cooler, the cooling efficiency of the shared intercooler 24 can be increased.
(5) The recirculated gas is recirculated to a portion (here, a surge tank) where the temperature rises due to the compression of the compressor 43 in the intake system. As a result, in the surge tank portion of the intake manifold 23, the difference between the temperature of the intake air and the temperature of the recirculation gas recirculated from the EGR passage 51 is reduced, and is likely to occur due to the temperature difference between the intake air and the recirculation gas. Inspiratory pulsation is also suppressed.

  (6) Similarly, the recirculation gas is circulated through the intake manifold 23 (surge tank) downstream of the compressor 43 so that the compressor 43 itself is not exposed to the recirculation gas as high-temperature exhaust gas. This eliminates the need for heat resistance measures for the compressor as described in, for example, Japanese Patent Application Laid-Open No. 6-257518, and the compressor 43 can be made of, for example, an aluminum alloy that has low heat resistance but is lightweight. .

(Second Embodiment)
FIG. 2 shows a schematic configuration of a second embodiment of the internal combustion engine with an intercooler according to the present invention. In the following description, a specific configuration of the internal combustion engine will be mainly described focusing on differences from the first embodiment. In FIG. 2, the same members as those in the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and redundant description thereof is omitted.

  In the second embodiment, as in the internal combustion engine illustrated in FIG. 3, an intercooler is provided upstream of the throttle body in the intake system, and the end portion of the EGR passage on the intake system side is further upstream of the intercooler. To connect.

  That is, as shown in FIG. 2, in the internal combustion engine, the intake passage 2 is provided with a water-cooled intercooler 26 between the compressor 43 and the throttle body 22 to connect the exhaust passage 3 and the intake passage 2. The EGR passage 61 of the EGR device 6 has an intake system side end 61 </ b> B connected downstream of the compressor 43 and upstream of the intercooler 26. In this embodiment, the EGR passage (exhaust gas recirculation passage) 61 is provided with the EGR valve 63 for adjusting the flow rate of the exhaust gas (recirculation gas) to be recirculated to the intake passage 2. The EGR cooler (152) like the illustrated internal combustion engine is not provided, and is shared by the intercooler 26. Note that such an EGR device 6 is also effective in circulating the recirculation gas to the intake system in order to reduce the amount of NOx generated, as in the first embodiment, and cools the recirculation gas. The intercooler 26 shares a cooler for the purpose. As a result, the EGR cooler can be reduced from the EGR device 6, and the mountability of the internal combustion engine on the vehicle is improved accordingly.

  As described above, the present embodiment can provide an effect equivalent to or equivalent to the effects (1), (3), and (4) of the first embodiment, and the following effects. Can be obtained.

  (7) The intercooler 26 is provided between the compressor 43 and the throttle body 22, and the intake system side end 61 </ b> B of the EGR passage 61 is connected downstream of the compressor 43 and upstream of the intercooler 26. As a result, the intercooler 26 can be shared for cooling the recirculated gas in the form of diverting the structure of the intake system that has been generally employed as an internal combustion engine with an intercooler.

  (8) The recirculated gas is recirculated to a portion of the intake system where the temperature is increased by compression of the compressor 43 (here, upstream of the intercooler 26). As a result, the difference between the temperature of the intake air and the temperature of the recirculation gas recirculated from the EGR passage 61 becomes small in the intake passage 2, and the intake air that is likely to be generated due to the temperature difference between the intake air and the recirculation gas. Pulsation is also suppressed.

  (9) Similarly, the recirculation gas is circulated downstream of the compressor 43 and upstream of the intercooler 26 so that the compressor 43 itself is not exposed to the recirculation gas that is high-temperature exhaust gas. This eliminates the need for heat resistance countermeasures for the compressor as in the case of the first embodiment described above, and the compressor 43 can be made of, for example, a lightweight aluminum alloy with low heat resistance.

In addition, each said embodiment can also be implemented in the following aspects, for example.
In each of the above-described embodiments, the shared intercooler 24 or 26 is water-cooled. However, these intercoolers are not limited to the water-cooled type, and may be, for example, an air-cooled type. Moreover, what used gas etc. for the refrigerant | coolant may be used.

  In each of the above embodiments, the exhaust system side ends 51A and 61A of the EGR passages 51 and 61 are connected to the exhaust manifold 31, but the exhaust system side ends are not limited to the exhaust manifold, and the exhaust passage 3 It may be connected to any location. That is, the exhaust system side end may be any one connected to a location where exhaust can be drawn into the exhaust recirculation passage.

  In each of the above embodiments, the turbocharger 4 that drives the turbine 41 by exhaust is adopted as the supercharger. However, the supercharger is not limited to the turbocharger, and may be a supercharger or the like.

  In each of the above embodiments, only the case where the arrangement of the EGR cooler in the EGR passage 51 or 61 is omitted has been described, but an EGR cooler may be provided in the exhaust circulation passage. Even if these exhaust gas recirculation passages are provided with an EGR cooler, the exhaust gas to be recirculated is cooled by an intercooler, and therefore, a small EGR cooler with a low cooling capacity is sufficient in this case. Even in this case, the downsizing of the internal combustion engine is promoted with the downsizing of the EGR cooler, so that the mountability to the vehicle is maintained. In this case, the location where the EGR cooler is provided may be upstream or downstream of the EGR valve in the exhaust recirculation passage.

  In each of the above embodiments, an in-line four-cylinder internal combustion engine is assumed as an example of an internal combustion engine with an intercooler, but the number of cylinders as the internal combustion engine is not limited to four, and the arrangement of these cylinders The type is not limited to the serial type, and may be a V-type arrangement or a horizontally opposed arrangement. Furthermore, there is no particular limitation on the type of internal combustion engine, and the present invention can be applied to, for example, a gasoline engine or a diesel engine.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic which shows the structure typically about 1st Embodiment of the internal combustion engine with an intercooler concerning this invention. BRIEF DESCRIPTION OF THE DRAWINGS The schematic which shows the structure typically about 2nd Embodiment of the internal combustion engine with an intercooler concerning this invention. 1 is a schematic view schematically showing the configuration of a conventional internal combustion engine with an intercooler.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Engine main body, 2 ... Intake passage, 3 ... Exhaust passage, 4 ... Turbocharger, 5, 6 ... Exhaust gas recirculation device (EGR device), 21 ... Air cleaner, 22 ... Throttle body, 23 ... Intake manifold, 24, 26 ... Intercooler, 31 ... Exhaust manifold, 32 ... Catalytic converter, 41 ... Turbine, 42 ... Turbine housing, 43 ... Compressor, 44 ... Compressor housing, 45 ... Rotary shaft, 51, 61 ... EGR passage (exhaust recirculation passage), 51A , 61A ... exhaust system side end, 51B, 61B ... intake system side end, 53, 63 ... EGR valve.

Claims (5)

An internal combustion engine with an intercooler that cools the intake air compressed by the supercharger with an intercooler and supplies it to the engine combustion chamber,
An exhaust gas recirculation device that recirculates a part of the exhaust gas discharged from the engine combustion chamber to the exhaust passage to the intake system via the exhaust circulation passage, and an end portion of the exhaust circulation passage on the intake system side in the intake system An internal combustion engine with an intercooler, which is connected between a supercharger and an intercooler. 2. The intercooler is provided integrally with an intake manifold that also serves as a surge tank of the engine, and an intake system side end of the exhaust recirculation passage is connected to a surge tank portion of the intake manifold. An internal combustion engine with an intercooler as described in 1. A throttle body including a throttle valve is provided in parallel with the exhaust gas recirculation passage upstream of the surge tank of the intake manifold that also serves as the surge tank, and the flow rate of the recirculation gas flowing in the exhaust recirculation passage is adjusted to the exhaust gas circulation passage. The internal combustion engine with an intercooler according to claim 2. The internal combustion engine with an intercooler according to claim 1, wherein the intercooler is provided upstream of a throttle body including a throttle valve. The internal combustion engine with an intercooler according to any one of claims 1 to 4, wherein the intercooler is a water-cooled cooler.

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