JP3669275B2 - EGR gas cooling device for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an EGR gas cooling device for cooling EGR gas recirculated from an exhaust system to an intake system in an exhaust gas recirculation (EGR) device of an internal combustion engine.
[0002]
[Prior art]
As is well known, an exhaust gas recirculation device that recirculates part of the exhaust gas to the intake system has been conventionally used in order to reduce NOx of the internal combustion engine, and the exhaust gas recirculation device flows into the intake system. It has been conventionally known to provide an EGR gas cooling device for cooling the EGR gas in order to reduce the temperature of exhaust gas, that is, EGR gas, for example, and to suppress the thermal influence when the intake manifold is made of synthetic resin, for example. ing.
[0003]
The conventional EGR gas cooling apparatus uses an EGR gas cooler composed of an independent kind of heat exchanger, and has a configuration in which EGR gas and cooling water are introduced through an external pipe, so the number of parts is very large. As the number increases, there is a drawback that the entire layout including piping of the cooling water becomes complicated.
[0004]
On the other hand, Japanese Patent Laid-Open No. 11-82185 discloses an EGR gas passage in which an EGR gas passage is formed in a cylinder head having a water jacket therein, and the water jacket is placed close to the EGR gas passage. The structure which cools is disclosed. In this configuration, the EGR gas passage is formed as a simple passage, and the EGR valve that controls the exhaust gas recirculation amount is attached to the side surface of the cylinder head that is the inlet side of the EGR gas passage. .
[0005]
[Problems to be solved by the invention]
In the above conventional configuration, since the EGR valve is disposed outside the cylinder head, the cooling action of the EGR valve by the cooling water flowing in the cylinder head can hardly be expected. In recent years, EGR valves in exhaust gas recirculation devices are configured to variably control the opening degree of the valve body using, for example, a step motor in order to control the exhaust gas recirculation amount with high accuracy. There is a problem that heat resistance is low, and therefore, the maximum flow rate that can pass through the EGR valve, that is, the maximum exhaust gas recirculation amount is limited by the heat resistance limit. In particular, since the EGR gas taken out from the exhaust manifold is guided to the EGR valve before being cooled by the cooling water, the EGR valve is easily exposed to high temperatures.
[0006]
Further, in the configuration described in the above publication, since the EGR gas passage is formed in the cylinder head itself, the structure of the water jacket with respect to the EGR gas passage cannot always be optimized due to restrictions of the casting core, etc. There exists a subject that it is difficult to ensure sufficient cooling performance of EGR gas by the flow of effective cooling water.
[0007]
[Means for Solving the Problems]
In the EGR gas cooling device for an internal combustion engine according to claim 1, a part of the cylinder head is formed as a gas cooler housing separately from the cylinder head main body, and the gas cooler housing has a flange that forms a joint surface on the outer peripheral edge. And an inner portion of the flange portion is recessed as a water jacket, and an opening corresponding to the flange portion is provided on an end surface of the cylinder head body, and the gas cooler housing and the cylinder head body A water jacket on the cylinder head side is formed continuously, and a cooling water inlet through which cooling water flows from the radiator to the cylinder head side water jacket is provided in the gas cooler housing, and a wall portion of the gas cooler housing The EGR gas inlet connected to the exhaust system and An EGR gas passage having an EGR gas outlet connected to the intake system is formed, and a valve housing chamber for housing an EGR valve is formed in the middle of the EGR gas passage, and the EGR gas passage is configured. A tubular portion to be formed and an outer wall portion of the valve accommodating chamber constituting the valve accommodating chamber are formed to bulge inside the wall portion and are exposed in the water jacket . The valve housing chamber is formed in the cylinder head in a concave shape having at least a part opened, and the valve body of the EGR valve housed therein opens and closes the EGR gas passage. Since the valve housing chamber is provided integrally with the cylinder head, the EGR valve itself is also cooled by the cooling water, and the EGR gas is cooled through a part of the EGR gas passage in the cylinder head. Since it reaches the valve body portion of the EGR valve after receiving, the thermal influence of the EGR valve is small.
[0008]
The tubular portion and the outer wall portion of the valve storage chamber are formed with an appropriate thickness, and thereby, the EGR gas passage and the valve storage chamber are configured inside the wall portion of the gas cooler housing. Since the tubular portion and the outer wall portion of the valve accommodating chamber swell in the water jacket, the heat exchange area with the cooling water increases.
In the present invention, a part of the cylinder head is separately formed as a gas cooler housing, for example, by casting, and then fixed integrally with each other, and a water jacket is formed therebetween. Therefore, the shape of the water jacket for the EGR gas passage formed inside the gas cooler housing can be easily optimized.
[0009]
Then, the above-mentioned cooling water inlet, the cold coolant is introduced back from the radiator, this low temperature coolant, EGR gas passage and the valve accommodating chamber is actively cooled.
[0012]
In a more invention specific claim 2, the surface of the upper Symbol tube-shaped portion, the rib-like heat sink are integrally formed. This heat sink increases the heat exchange area with the cooling water. However, since the heat sink is formed on the gas cooler housing side in a state where the water jacket is divided, its formation is easy.
[0014]
Furthermore, in the invention of claim 3, the surface of the upper Fang Lube receiving chamber outer wall, the rib-like heat sink are integrally formed.
[0017]
In this case , as in claim 4 , it is more desirable that the cooling water flowing into the water jacket from the cooling water inlet is directed to the heat sink.
[0018]
Upper Symbol valve chamber, as claimed in claim 5, between the exhaust side and the intake side of the cylinder head, it is preferably disposed at a position relatively close to the intake side. Since the cylinder head generally has a smaller thermal load on the intake side than on the exhaust side, the cylinder head is preferably arranged close to the intake side. Moreover, since the EGR gas passage is normally formed in the cylinder head so that EGR gas flows from the exhaust side to the intake side, the EGR gas up to the EGR valve can be obtained by shifting the valve storage chamber toward the intake side. The passage length of the passage becomes relatively long, which is advantageous in reducing the thermal influence on the EGR valve.
[0019]
According to a sixth aspect of the present invention, one end of the valve housing chamber is opened upward, and the EGR valve is mounted in a state where the drive motor portion projects outside from the open end. As a result, heat transfer to the drive motor section that is the weakest thermally is suppressed, and the cooling action by the outside air is received.
[0020]
According to a seventh aspect of the present invention, an inlet side portion and an outlet side portion of the EGR gas passage are arranged in a stepped shape with the valve accommodating chamber interposed therebetween, and the valve accommodating chamber is disposed from the inlet side portion to the above-mentioned portion. It is characterized by being formed so as to be inclined along the flow of exhaust toward the outlet side portion. As a result, the EGR gas flows more smoothly from the inlet side portion to the outlet side portion of the EGR gas passage through the EGR valve, and the passage resistance in the EGR valve is reduced.
[0021]
According to an eighth aspect of the present invention, the internal combustion engine is mounted horizontally on the vehicle so that the intake side of the cylinder head faces the front of the vehicle, and the valve storage chamber is located between the exhaust side and the intake side of the cylinder head. The upper end opening is inclined so as to go diagonally forward of the vehicle, and the drive motor portion projects outside from the opening end. The EGR valve is attached to the state. Therefore, in the vehicle-mounted state, the EGR valve is disposed at a position closer to the front of the vehicle and obliquely toward the front. Therefore, it is advantageous in terms of maintainability and thermal influence of the EGR valve. In particular, when the hood of the engine room opens with the rear part as a hinge, it is more advantageous in terms of maintainability.
[0022]
According to a ninth aspect of the present invention, it is desirable that the EGR gas inlet is open in the same direction as the exhaust manifold mounting surface of the cylinder head. Thus, for example, as in claims 1 to 3, it is possible to connect directly with the EGR gas passage formed integrally with the exhaust manifold.
[0023]
Similarly, as in claim 1 0, the EGR gas outlet is preferably opened toward the same direction as the intake manifold mounting surface of the cylinder head. Thus, for example, as in claims 1 to 3, it is possible to connect directly with the EGR gas passage formed integrally with the intake manifold.
[0024]
Furthermore, as in claim 1 1, the EGR gas inlet is preferably open to the same plane as the exhaust manifold mounting surface of the cylinder head. As a result, the EGR gas passage can be sealed with a gasket between the exhaust manifold and the exhaust manifold.
[0025]
Similarly, as in claim 1 2, the EGR gas outlet is preferably open to the same plane as the intake manifold mounting surface of the cylinder head. As a result, the EGR gas passage can be sealed with a gasket between the intake manifold and the intake manifold.
[0026]
【The invention's effect】
According to the present invention, the EGR gas recirculated from the exhaust system to the intake system is effectively cooled by using the cooling water flowing through the water jacket on the cylinder head side while avoiding the complexity of the layout due to external piping or the like. can do.
[0027]
In particular , the EGR valve itself can be effectively cooled, and EGR gas that has been cooled to some extent can pass through the EGR valve, thereby reducing the thermal influence on the EGR valve having low heat resistance. Therefore, the durability of the EGR valve is improved and a larger amount of EGR gas can be recirculated to the intake system.
[0028]
Moreover , the flow of the cooling water, the heat exchange area, etc. with respect to the EGR gas passage and the EGR valve can be easily optimized without being restricted by the core at the time of casting the cylinder head.
[0029]
Furthermore, according to the configurations of claims 10 to 13 , it is possible to supply EGR gas from the exhaust manifold to the intake manifold through the EGR gas passage in the cylinder head without using external piping, thereby simplifying the configuration and working. Can improve the performance.
[0030]
According to the seventh aspect of the present invention, the passage resistance by the intermediate EGR valve is reduced, and the exhaust gas recirculation can be performed better when the pressure difference between the exhaust system and the intake system is small.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
[0032]
1 to 5 show an embodiment in which the present invention is applied to an in-line four-cylinder internal combustion engine. As shown in FIG. 2, the internal combustion engine is roughly constituted by a cylinder block 1 in which four cylinders (not shown) are formed, and a cylinder head 2 fixed to the upper surface of the cylinder block 1. The exhaust manifold 3 is attached to one side surface of the cylinder head 2, the intake manifold 4 is attached to the other side surface, and the upper surface of the cylinder head 2 is covered with a cylinder head cover 5. In the exhaust manifold 3, four branch portions 6 are gathered into one catalytic converter mounting portion 7. In the intake manifold 4, each branch portion 9 extends to a collector mounting flange 8 to which a collector (not shown) is mounted, and a fuel injection valve mounting portion 10 is provided for each cylinder. In this embodiment, the internal combustion engine is mounted in a so-called horizontal posture in the engine room at the front of the vehicle, and the intake manifold 4 side, that is, the left side in FIGS. It becomes.
[0033]
The cylinder block 1 is integrally cast from cast iron, aluminum alloy, or the like, and a water jacket (not shown) continuous before and after surrounding each cylinder is formed therein. Similarly, a water jacket (described later) surrounding the periphery of the combustion chamber and intake / exhaust ports (not shown) is also formed on the cylinder head 2 side in a continuous manner in the front-rear direction. The water jacket on the cylinder block 1 side and the water jacket on the cylinder head 2 side normally communicate with each other through a large number of communication holes (not shown) in the joint surface between them. An independent configuration can also be adopted.
[0034]
As shown in FIG. 1, the cylinder head 2 includes a cylinder head body 11 that forms a main part including each combustion chamber and intake / exhaust ports, and a gas cooler housing 12 that is attached to the front end of the cylinder head body 11. Has been. The cylinder head body 11 is integrally cast using, for example, an aluminum alloy, and a water jacket continuous in the front-rear direction is formed therein as described above. In the front end surface of 11, the internal water jacket is in a state of wide opening over substantially the front surface. The gas cooler housing 12 is also integrally cast using an aluminum alloy or the like, has a kind of cover that covers the opening surface of the water jacket, and is illustrated via a gasket, for example, a liquid gasket. A plurality of bolts are attached to the front end surface of the cylinder head body 11.
[0035]
FIG. 3 shows a state where the gas cooler housing 12 is attached to the cylinder head body 11, and FIG. 4 shows a state where only the gas cooler housing 12 is removed. FIG. 5 shows the gas cooler housing 12 alone from the back side.
[0036]
As shown in these drawings, the gas cooler housing 12 has a flange portion 15 as a joint surface formed on the outer peripheral edge on the cylinder head body 11 side over the entire circumference, and the inner portion thereof is recessed as a water jacket 16. It is. In other words, the cover is integrally formed into a cover having an appropriate thickness with one surface opened. An opening having substantially the same shape is provided on the front end surface of the cylinder head body 11 (not shown) corresponding to the shape of the flange portion 15, so that the water jacket 16 in the gas cooler housing 12 is a cylinder. It constitutes a part of the water jacket on the head 2 side. A plurality of boss portions 17 through which mounting bolts (not shown) pass are formed in the vicinity of the flange portion 15.
[0037]
An EGR gas passage 18 is formed through the wall of the front surface of the gas cooler housing 12 along the left-right direction of the cylinder head 2. The EGR gas passage 18 is constituted by a tubular portion 19 formed by expanding the wall portion of the gas cooler housing 12 inward and outward in a substantially semicircular cross section. That is, a part of the tubular portion 19 bulges outward as shown in FIG. 4 and a part bulges inward as shown in FIG. 5 and is exposed in the water jacket 16. The EGR gas passage 18 has an EGR gas inlet 20 on one side of the gas cooler housing 12 on the exhaust manifold 3 side of the cylinder head 2, and an EGR gas outlet on the other side of the cylinder head 2 on the intake manifold 4 side. 21. The EGR gas passage 18 is divided into a linear inlet side portion 18A and an outlet side portion 18B, and the latter outlet side portion 18B is arranged in steps so as to be positioned slightly above. In addition, a valve housing chamber 22 having a bottomed cylindrical shape is formed at a position serving as a boundary between the two. That is, the inlet side portion 18A and the outlet side portion 18B are continuous as a single passage through the valve storage chamber 22.
[0038]
The valve accommodating chamber 22 has a diameter larger than that of the EGR gas passage 18 and is formed so as to be inclined so that the opening 22a at the upper end is directed toward the intake system, and one end of the inlet side portion 18A is opened at the bottom thereof. One end of the outlet side portion 18B is opened on the side surface. Similar to the tubular portion 19 of the EGR gas passage 18, the valve housing chamber 22 is configured by a valve housing chamber outer wall portion 23 in which a wall portion of the gas cooler housing 12 is expanded inward and outward in a substantially semicircular cross section. ing. That is, a part of the outer wall 23 of the valve accommodating chamber bulges outward as shown in FIG. 4 and a part bulges inward as shown in FIG. 5 and is exposed in the water jacket 16.
[0039]
As shown in FIGS. 4 and 5, the valve housing chamber 22 is formed at a position offset toward the intake side of the cylinder head 2. Therefore, the inlet side portion 18 </ b> A of the EGR gas passage 18 is relatively Long and the outlet side portion 18B is very short. As shown in FIG. 5, in the water jacket 16, a plurality of rib-like heat sinks 24 are integrally formed on the tubular portion 19 that is the inlet side portion 18 </ b> A, and the outer wall of the valve housing chamber Similarly, a plurality of rib-shaped heat sinks 25 are formed integrally with the portion 23.
[0040]
The opening 22a of the valve housing chamber 22 is open to a substantially circular valve mounting flange 26 formed obliquely on the upper side of the gas cooler housing 12, and as shown in FIGS. In addition, an EGR valve 31 is attached. The EGR valve 31 includes a valve portion 32 including a seat portion 33 and a valve body 34 through which EGR gas flows, and a drive motor portion 35 that drives the valve body 34 up and down. The valve portion 32 is accommodated in the valve accommodating chamber 22, and the drive motor portion 35 protrudes to the outside. The seat portion 33 is located toward the bottom surface of the valve accommodating chamber 22 to which the inlet side portion 18A of the EGR gas passage 18 is connected, and the outlet side portion 18A is opened to the outlet side portion as the valve body 34 is opened and closed. The flow rate of EGR gas flowing to 18B is controlled.
[0041]
A cooling water inlet 41 having a pipe portion 41a for connecting a hose is formed at a position opposite to the valve accommodating chamber 22 at the upper part of the gas cooler housing 12. The cooling water inlet 41 serves as a cooling water inlet for the entire water jacket in the cylinder head 2 and has a circular shape located at the upper corner of the water jacket 16 in the gas cooler housing 12 as shown in FIG. The water jacket 16 communicates with the opening 41b. Further, the pipe portion 41a extends obliquely forward as shown in FIG. 1, and particularly extends to the side on the exhaust system side as clearly shown in FIGS. Accordingly, the low-temperature cooling water fed by a water pump (not shown) flows into the water jacket 16 as having the velocity component in the left-right direction in FIGS. 4 and 5, and the heat sink 25 and the tubular shape of the outer wall portion 23 of the valve housing chamber. It flows to the heat sink 24 of the part 19, and these can be actively cooled. In this embodiment, a pipe connector portion 42 is returned to the pipe portion 41a to which cooling water that has cooled a not-shown throttle valve driving motor is returned.
[0042]
In the state where the gas cooler housing 12 is attached to the cylinder head body 11, one flange surface 45 through which the EGR gas inlet 20 opens is flush with one side surface of the cylinder head body 11 to which the exhaust manifold 3 is attached. There is no. At the same time, the other flange surface 46 through which the EGR gas outlet 21 opens is flush with the other side surface of the cylinder head body 11 to which the intake manifold 4 is attached.
[0043]
The exhaust manifold 3 is provided with an extension 3a extending to the side of the gas cooler housing 12, and an EGR gas passage 47 is formed through the extension 3a. Connected to the inlet 20. In particular, a part of a sheet-like gasket (not shown) disposed between the exhaust manifold 3 and the cylinder head body 11 is provided between the EGR gas passage 47 on the exhaust manifold 3 side and the EGR gas inlet 20. Is sealed. The EGR gas passage 47 communicates with the exhaust passage in the exhaust manifold 3 at an appropriate position. Similarly, the intake manifold 4 is provided with an extension portion 4a extending to the side of the gas cooler housing 12, and an EGR gas passage 48 is formed through the inside of the extension portion 4a. The EGR gas outlet 21 is connected. A part of a gasket (not shown) disposed between the intake manifold 4 and the cylinder head body 11 seals between the EGR gas passage 48 on the intake manifold 4 side and the EGR gas outlet 21. ing. The EGR gas passage 48 extends along the cylinder row direction as shown in FIG. 1, and distributes EGR gas to each cylinder.
[0044]
Accordingly, after a part of the exhaust is directly led from the exhaust manifold 3 through the EGR gas passage 47 to the EGR gas passage 18 of the gas cooler housing 12, the heat is exchanged with the cooling water and the temperature is lowered. , Flows to the EGR gas passage 48 of the intake manifold 4. The flow of the EGR gas is controlled by the EGR valve 31 disposed in the valve storage chamber 22, and the valve storage chamber 22 and the EGR valve 31 are moved from the inlet side portion 18 </ b> A to the outlet side portion 18 </ b> B of the EGR gas passage 18. Therefore, the EGR gas flows smoothly even under conditions where the pressure difference is relatively small.
[0045]
In the configuration of the above embodiment, the EGR gas passage 18 and the valve storage chamber 22 are actively cooled in the cylinder head 2 by the cooling water flowing through the water jacket 16, and particularly in the inlet side portion 18 </ b> A of the EGR gas passage 18. Since the EGR gas enters the valve housing chamber 22 after being cooled, the amount of heat transmitted to the EGR valve 31 is reduced, and the temperature increase of the drive motor unit 35 can be sufficiently suppressed. In particular, the drive motor unit 35 is located on the side of the intake system having a lower heat load as a whole of the cylinder head 2 and is also cooled by outside air toward the front of the vehicle, which is advantageous in suppressing temperature rise. Therefore, a larger amount of EGR gas can be recirculated. Such an arrangement of the EGR valve 31 makes the maintenance of the EGR valve 31 very excellent, particularly when the hood of the vehicle opens with the rear part as a hinge. In addition, since the EGR gas passage 18 and the valve storage chamber 22 are cooled at the most upstream of the series of water jackets on the cylinder head 2 side, the cooling is performed well by the low-temperature cooling water together with the formation of the heat sinks 24 and 25. .
[0046]
In addition, as described above, the gas cooler housing 12 is cast and combined separately from the cylinder head main body 11, so that the formation of the heat sinks 24 and 25, the layout of the cooling water inlet 41, etc. can be cooled without being restricted by the core. It is easy to optimize the performance. On the other hand, the EGR gas passage 20 provided in the exhaust manifold 3 or the intake manifold 4 by aligning the EGR gas inlet 20 or the EGR gas outlet 21 with the mounting surface of the exhaust manifold 3 or the intake manifold 4. 47 and 48 can be directly connected and the gasket can be shared, so that the complicated structure and the increase in the number of parts associated with the gas cooler housing 12 being separated are avoided as much as possible.
[0047]
In the above-described embodiment, the example in which one end portion in the longitudinal direction of the cylinder head is configured separately as a gas cooler housing has been described. However, the EGR gas passage and the valve housing chamber are similarly formed in the integrally cast cylinder head itself. You can also
[Brief description of the drawings]
FIG. 1 is a plan view of an internal combustion engine including an EGR gas cooling device according to the present invention.
FIG. 2 is a front view of the internal combustion engine.
FIG. 3 is a front view of a cylinder head including a gas cooler housing.
FIG. 4 is a front view of a gas cooler housing provided with an EGR valve.
FIG. 5 is a rear view of only the gas cooler housing.
[Explanation of symbols]
3 ... Exhaust manifold 4 ... Intake manifold 11 ... Cylinder head body 12 ... Gas cooler housing 16 ... Water jacket 18 ... EGR gas passage 22 ... Valve housing chambers 24, 25 ... Heat sink 31 ... EGR valve 41 ... Cooling water inlet

Claims (13)

A part of the cylinder head is formed as a gas cooler housing separately from the cylinder head main body, and the gas cooler housing has a flange portion that serves as a joint surface on the outer peripheral edge, and an inner portion of the flange portion is a water jacket. And an opening corresponding to the flange portion is provided on the end surface of the cylinder head body, and a water jacket on the cylinder head side is formed continuously in the gas cooler housing and the cylinder head body. And
A cooling water inlet through which cooling water flows from the radiator to the cylinder head side water jacket is provided in the gas cooler housing,
An EGR gas passage having an EGR gas inlet connected to the exhaust system and an EGR gas outlet connected to the intake system is formed in the wall portion of the gas cooler housing, and an EGR valve is provided in the middle of the EGR gas passage. A valve storage chamber for storing
The tubular portion constituting the EGR gas passage and the outer wall portion of the valve accommodating chamber constituting the valve accommodating chamber are formed to bulge inside the wall portion and are exposed in the water jacket. EGR gas cooling device for internal combustion engine. On the surface of the upper Symbol tube-shaped portion, the rib-like heat sink EGR gas cooling device for an internal combustion engine according to claim 1, characterized in that it is formed integrally. On the surface of the upper Fang Lube receiving chamber outer wall, the rib-like heat sink EGR gas cooling device for an internal combustion engine according to claim 1 or 2, characterized in that it is formed integrally. EGR gas cooling device for an internal combustion engine according to claim 2 or 3 cooling water flowing in the water jacket from the top Symbol cooling water inlet is characterized by being configured so as to be directed to the heat sink. The internal combustion engine according to any one of claims 1 to 4, wherein the valve housing chamber is disposed at a position relatively close to the intake side between the exhaust side and the intake side of the cylinder head. EGR gas cooling device. It said valve chamber is open at one end upwardly, either the drive motor unit from the open end to a state of protruding to the outside, according to claim 1-5, characterized in that the EGR valve is mounted An EGR gas cooling device for an internal combustion engine according to claim 1. An inlet side portion and an outlet side portion of the EGR gas passage are arranged in a stepped shape with the valve storage chamber interposed therebetween, and the valve storage chamber is configured to prevent exhaust gas flowing from the inlet side portion to the outlet side portion. The EGR gas cooling apparatus for an internal combustion engine according to any one of claims 1 to 6 , wherein the EGR gas cooling apparatus is inclined so as to follow the flow. The internal combustion engine is mounted horizontally on the vehicle so that the intake side of the cylinder head faces the front of the vehicle, and the valve storage chamber is relatively close to the intake side between the exhaust side and the intake side of the cylinder head. The EGR valve is mounted in such a manner that the opening at the upper end is inclined so as to be inclined obliquely forward of the vehicle, and the drive motor portion projects outside from the opening end. The EGR gas cooling device for an internal combustion engine according to any one of claims 1 to 7, wherein The EGR gas cooling device for an internal combustion engine according to any one of claims 1 to 8, wherein the EGR gas inlet opens in the same direction as an exhaust manifold mounting surface of a cylinder head. The EGR gas cooling device for an internal combustion engine according to any one of claims 1 to 9, wherein the EGR gas outlet opens in the same direction as the intake manifold mounting surface of the cylinder head. 10. The EGR gas cooling device for an internal combustion engine according to claim 9 , wherein the EGR gas inlet opens on the same plane as an exhaust manifold mounting surface of a cylinder head. 11. The EGR gas cooling device for an internal combustion engine according to claim 10 , wherein the EGR gas outlet is opened on the same surface as an intake manifold mounting surface of a cylinder head. Exhaust and EGR gas passage in at least one of the manifold or intake manifold is formed integrally with the claims 9 to 12 the EGR gas passage, characterized in that it is directly connected to the EGR gas inlet or EGR gas outlet The EGR gas cooling device for an internal combustion engine according to any one of the above.

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