JP4324967B2 - Exhaust gas recirculation control device - Google Patents

Description

  The present invention relates to an exhaust gas recirculation control device (hereinafter referred to as “exhaust gas recirculation”) that controls the temperature of exhaust gas to be recirculated by introducing it into the intake system of an internal combustion engine (hereinafter referred to as “the internal combustion engine”). About).

  Patent Document 1 discloses an EGR control device that includes a cooling passage that circulates exhaust gas while cooling, a bypass passage that bypasses the cooling passage and circulates exhaust gas, and a butterfly valve that opens and closes the bypass passage. ing. In this EGR control device, by opening the bypass passage by the butterfly valve, the exhaust gas that has passed through the bypass passage and the exhaust gas that has passed through the cooling passage can be mixed and guided to the intake system. Therefore, if the opening degree of the butterfly valve is adjusted, the mixing ratio of the exhaust gas from each passage changes, and the temperature of the exhaust gas guided to the intake system also changes.

European Patent Application No. 0987427

However, in the EGR control device of Patent Document 1, since the valve shaft of the butterfly valve extends in the bypass passage, the bearing that supports the valve shaft is exposed to high-temperature exhaust gas that has passed through the bypass passage. Therefore, when the heat of the high-temperature exhaust gas is transmitted to the bearing through the valve shaft, the bearing rises in temperature and melts, resulting in malfunction such as valve locking. Moreover, since the amount of thermal expansion of the bearing increases due to the temperature rise, the clearance between the valve shaft and the bearing must be set large, thereby reducing the vibration resistance.
As a method for solving such a problem, a method of cooling a bearing exposed to a high temperature with a refrigerant can be considered. However, in this method, since a refrigerant circulation device has to be added, the EGR control device is increased in size. Incurs an increase in cost.
An object of the present invention is to provide a small and inexpensive EGR control device that achieves prevention of malfunction and improvement of vibration resistance.

  According to the first aspect of the present invention, the swing shaft of the swing valve supported by the bearing and opening and closing the outlets of the cooling passage and the bypass passage extends in the cooling passage. Then, it is exposed to the low-temperature exhaust gas cooled by the cooling passage. Thereby, it can suppress that the temperature of a bearing raises with the heat | fever of the exhaust gas transmitted through a rocking | fluctuation shaft. For this reason, the bearing becomes difficult to melt depending on the heat received from the exhaust gas, and malfunction such as valve locking can be prevented. In addition, since the amount of thermal expansion of the bearing due to heat received from the exhaust gas is reduced, the vibration resistance can be improved by setting the clearance between the swing shaft and the bearing small. Since such an effect can be obtained by merely arranging the swing shaft so as to extend in the cooling passage without using a cooling device or the like, a small and inexpensive EGR control device can be realized.

  According to the second aspect of the present invention, the seal member for sealing between the swing shaft and the bearing is melted due to the heat of the exhaust gas transmitted through the swing shaft. Can be prevented. By preventing the sealing member from melting as described above, the sealing performance between the swing shaft and the bearing can be ensured over a long period of time.

According to the invention described in claim 3, the swing shaft is provided on the opposite side of the outlet portion of the bypass passage across the partition wall that partitions the outlet portion of the cooling passage and the outlet portion of the bypass passage. As a result, the high-temperature exhaust gas flowing through the bypass passage is blocked by the partition wall and does not easily reach the periphery of the swing shaft. Therefore, it is possible to suppress the temperature rise of the bearing due to the high-temperature exhaust gas.
According to the fourth aspect of the invention, since the downstream end of the exhaust gas flow in the partition wall is bent toward the swing shaft, the high-temperature exhaust gas flowing through the bypass passage further reaches the periphery of the swing shaft. It becomes difficult to suppress the temperature rise of the bearing.

  According to the fifth aspect of the present invention, the swing valve communicates the cooling passage and the outlet through the gap between the swing shaft and the partition when the bypass passage is opened. As a result, even if the bypass passage is opened, the low-temperature exhaust gas cooled by the cooling passage flows through the gap between the swing shaft and the partition wall. This makes it difficult for the exhaust gas to reach the periphery of the swing shaft. Therefore, it is possible to suppress the temperature rise of the bearing due to the high temperature exhaust gas.

According to the sixth aspect of the present invention, when the swing valve closes the bypass passage, the downstream end of the partition wall locks the swing valve, so there is no need to newly provide a part that exhibits the locking function. . Therefore, it is possible to contribute to a reduction in the number of parts and a cost reduction.
According to the seventh aspect of the present invention, when the swing valve closes the bypass passage, the downstream end of the partition wall locks the valve main body protruding radially outward from the swing shaft in the swing valve. As a result, the high-temperature exhaust gas flowing through the bypass passage is blocked by the valve main body and hardly reaches the periphery of the swing shaft, thereby promoting the effect of suppressing the temperature rise of the bearing.

Hereinafter, a plurality of embodiments and reference examples of the present invention will be described with reference to the drawings.
FIG. 2 shows an engine system 10 according to a first embodiment to which the present invention is applied. An engine system 10 mounted and used in a vehicle includes an engine 12, an intake system 20, an exhaust system 30, an EGR system 40, and the like.

  The intake system 20 includes an intake pipe 21, an intake manifold 22, an air cleaner 23, and a throttle device 24. The intake pipe 21 and the intake manifold 22 form an intake passage through which air sucked from outside the vehicle flows. In the middle of the intake pipe 21, an air cleaner 23 and a throttle device 24 are interposed in this order from the upstream side. The air cleaner 23 removes foreign matter in the intake air flowing through the intake passage. The throttle device 24 adjusts the flow rate of intake air in the intake passage. The intake manifold 22 that connects the intake pipe 21 and the engine 12 includes a surge tank 26 and a plurality of branch pipes 27. The intake air whose flow rate is adjusted by the throttle device 24 is pulsated by the surge tank 26 and then distributed to each cylinder of the engine 12 by each branch pipe 27.

  The exhaust system 30 has an exhaust manifold 31 and an exhaust pipe 32. The exhaust manifold 31 and the exhaust pipe 32 form an exhaust passage through which exhaust gas discharged from the engine 12 flows. The exhaust manifold 31 includes a plurality of branch pipes 34 and a merging portion 35. Exhaust gases discharged from the cylinders of the engine 12 to the branch pipes 34 merge at the merge portion 35. The exhaust pipe 32 is connected to the junction 35 and discharges exhaust gas flowing from the junction 35 to the outside of the vehicle through the muffler of the vehicle.

  The EGR system 40 includes a reflux pipe 41, a temperature adjustment device 42, a flow rate adjustment device 43, a temperature sensor 44, and a controller 45. The recirculation pipe 41 is connected between the merging portion 35 of the exhaust manifold 31 and the surge tank 26 of the intake manifold 22, and a part of the exhaust gas flowing from the merging portion 35 is led to the surge tank 26 and recirculated to the engine 12. An EGR passage to be circulated is formed. A temperature adjusting device 42 and a flow rate adjusting device 43 are interposed in this order from the upstream side in the middle of the reflux pipe 41. That is, the reflux pipe 41 includes a first pipe part 47 between the merging part 35 and the temperature adjustment apparatus 42, a second pipe part 48 between the temperature adjustment apparatus 42 and the flow rate adjustment apparatus 43, and a flow rate adjustment apparatus 43 and a surge. A third pipe portion 49 between the tank 26 and the tank 26 is provided. The temperature adjusting device 42 is electrically connected to the controller 45, and adjusts the temperature of the exhaust gas led to the surge tank 26 in accordance with a command from the controller 45. The flow rate adjusting device 43 is electrically connected to the controller 45, and adjusts the flow rate of the exhaust gas led to the surge tank 26 by changing the opening of the EGR valve in accordance with a command from the controller 45. The temperature sensor 44 is attached to the third pipe portion 49 and detects the temperature of the exhaust gas led to the surge tank 26. The temperature sensor 44 is electrically connected to the controller 45, and outputs the detection result of the exhaust gas temperature to the controller 45. The controller 45 is mainly composed of a microcomputer and controls the temperature adjusting device 42, the flow rate adjusting device 43, and the like.

Next, the temperature adjustment device 42 and the controller 45 will be described in detail. As shown in FIGS. 1 and 4, the temperature adjustment device 42 includes an introduction part 51, a cooling part 52, a bypass part 53, a valve support part 54, a lead-out part 55, a partition wall 58, a swing valve 56, and a valve drive part 57. ing.
The introduction part 51 is formed in a cylindrical shape with a metal such as SUS. The introduction part 51 connected to the first pipe part 47 has an introduction port 60 into which exhaust gas from the exhaust manifold 31 is introduced on the inner side.

  The cooling case 61 of the cooling unit 52 is formed in a cylindrical shape with a metal such as SUS. The cooling case 61 is formed with two openings 64 and 65 connected to the cooling water system of the engine 12 via cooling water pipes 62 and 63 (see FIG. 2). A circulation path is formed for drawing water inward and returning water to the cooling water system by the other cooling water pipe 63. The gas pipe 66 of the cooling unit 52 is formed in a straight tube shape with a metal such as SUS, and a plurality of gas pipes 66 are provided in a form extending in parallel with each other in the cooling case 61. Both end portions of each gas pipe 66 are held by the retainers 67 and 68 so as to penetrate the retainers 67 and 68 that cover both end portions of the cooling case 61. As a result, the plurality of first passages 69 formed on the inner sides of the gas pipes 66 are blocked from communicating with the circulation portion of the cooling water in the cooling case 61. A retainer 67 that covers one end portion of the cooling case 61 is connected to the introduction portion 51, and one end portion of the first passage 69 in each gas pipe 66 held by the retainer 67 communicates with the introduction port 60. Each first passage 69 circulates the exhaust gas flowing from the inlet 60 to the one end side toward the other end side. At this time, the exhaust gas passing through each first passage 69 is cooled by the cooling water drawn into the cooling case 61.

  The bypass part 53 is formed of a metal such as SUS and has a cylindrical shape substantially parallel to each gas pipe 66 of the cooling part 52. One end portion of the bypass portion 53 is connected to the introduction portion 51 via the retainer 67, and one end portion of the second passage 70 formed inside by the bypass portion 53 communicates with the introduction port 60. The second passage 70 allows the exhaust gas flowing from the introduction port 60 to the one end side to flow toward the other end side.

  As shown in FIGS. 1, 3, and 4, the valve support 54 is formed in a cylindrical shape with a metal such as SUS, and the inside is partitioned into two by a partition wall 58. The valve support 54 forms a third passage 72 and a fourth passage 73 on both sides of the partition wall 58.

  The third passage 72 side of one end portion of the valve support portion 54 is connected to a retainer 68 that covers an end portion of the cooling case 61 opposite to the introduction portion 51, and each gas pipe 66 held by the retainer 68. A downstream end portion of the first passage 69 communicates with the third passage 72. As a result, the cooling passage 75 through which the exhaust gas is circulated is composed of a plurality of first passages 69 and third passages 72, and the third passage 72 forms the outlet portion 72 of the cooling passage 75. Yes. Bearings 78 and 79 embedded in the side walls 76 and 77 of the valve support portion 54 respectively support both end portions of the swing shaft 84 of the swing valve 56 so as to be swingable, and an intermediate portion 84 a of the swing shaft 84. Extends in the width direction of the outlet portion 72 in the outlet portion 72 of the cooling passage 75. A seal member 80 is interposed between the bearing 79 and the swing shaft 84 to prevent exhaust gas leakage from the cooling passage 75 into the valve drive unit 57.

  Further, the fourth passage 73 side of the one end portion of the valve support portion 54 is connected to an end portion of the bypass portion 53 opposite to the introduction portion 51 via a retainer 68, and the first end portion in the bypass portion 53 is connected. The downstream end of the second passage 70 communicates with the fourth passage 73. Thus, a bypass passage 81 that bypasses the cooling passage 75 and distributes the exhaust gas is constituted by the second passage 70 and the fourth passage 73, and the fourth passage 73 passes through the outlet 73 of the bypass passage 81. Forming.

  The lead-out part 55 is formed integrally with the valve support part 54 from a metal such as SUS. The cylindrical lead-out portion 55 has a lead-out port 83 having a central axis substantially perpendicular to the swing shaft 84 formed inside. The other end portion of the lead-out portion 55 whose one end portion is connected to the second pipe portion 48 is connected to an end portion of the valve support portion 54 opposite to the cooling portion 52 and the bypass portion 53. The outlet 83 in the outlet 55 communicates with the passage in which the outlets 72 and 73 are opened in the cooling passage 75 and the bypass passage 81, and exhaust gas flowing in from the connected passage passes through the EGR in the second pipe portion 48. Derived to the passage.

  The partition wall 58 is formed in a plate shape with a metal such as SUS and is fixed to the side walls 76 and 77 of the valve support portion 54. In the partition wall 58, an end portion 87 located on the downstream side of the exhaust gas flow passing through the cooling passage 75 and the bypass passage 81 is bent toward the swing shaft 84, and a portion excluding the downstream end portion 87 is a lead-out port. It is substantially parallel to the 83 central axis.

  The swing valve 56 is made of a metal such as SUS. As described above, the swing shaft 84 of the swing valve 56 is supported by the bearings 78 and 79 and extends in the cooling passage 75. Thus, the swing shaft 84 is located on the opposite side of the outlet portion 73 of the bypass passage 81 with the partition wall 58 interposed therebetween. The valve body 85 of the swing valve 56 is formed in a plate shape that protrudes radially outward from the outer peripheral surface of the swing shaft 84. The protrusion 86 of the swing valve 56 is formed in a plate shape that protrudes radially outward from the outer peripheral surface of the swing shaft 84 in a V-shape with the valve body 85.

The swing valve 56 swings in the valve support portion 54 and the lead-out portion 55 to open and close the outlet portions 72 and 73 of the cooling passage 75 and the bypass passage 81.
Specifically, the valve main body 85 and the protrusion 86 abut against the side walls 76 and 77 of the valve support 54 at any swing position.

  4, the valve main body 85 is locked to the first locking wall 88 of the valve support 54. As a result, the outlet portion 72 of the cooling passage 75 is closed and the outlet portion 73 of the bypass passage 81 is opened, and the high-temperature exhaust gas that has passed through the bypass passage 81 passes through the outlet 83 to the second pipe portion 48. Led. At this time, since the protruding portion 86 and the partition wall 58 are slightly separated from each other, the cooling passage 75 and the outlet port 83 communicate with each other through the gap 90 between the swing shaft 84 and the downstream end portion 87 of the partition wall 58. The exhaust gas in the cooling passage 75 flows through the gap 90.

  5, the valve main body 85 is locked to the second locking wall 89 of the valve support 54 and the downstream end 87 of the partition wall 58. As a result, the outlet portion 73 of the bypass passage 81 is closed and the outlet portion 72 of the cooling passage 75 is opened, and the low-temperature exhaust gas cooled by the cooling passage 75 passes to the second pipe portion 48 via the outlet port 83. It is guided.

  Furthermore, as shown in FIG. 6, the valve main body 85 is in any of the first and second locking walls 88 and 89 and the partition wall 58 at the swing position between the first swing position and the second swing position. Is not locked. As a result, the outlet portions 72 and 73 of both the cooling passage 75 and the bypass passage 81 are opened, and the exhaust gas from the passages 75 and 81 merges and mixes at the outlet 83, and the mixed gas flows into the outlet 83. To the second pipe 48. Therefore, when the rocking position of the rocking valve 56 changes between the first rocking position and the second rocking position, the mixing ratio of the exhaust gas from the passages 75 and 81 changes, and the second pipe portion The temperature of the derived gas to 48 changes. At this time, since the protruding portion 86 and the partition wall 58 are separated from each other, the cooling passage 75 and the outlet 83 are communicated with each other through the gap 90 between the swing shaft 84 and the downstream end portion 87 of the partition wall 58. Exhaust gas in the cooling passage 75 flows through the gap 90.

The valve drive unit 57 shown in FIG. 1 is electrically connected to the controller 45 shown in FIG. 2 and adjusts the swing position of the swing valve 56 in accordance with a command from the controller 45.
Based on the detection result of the exhaust gas temperature output from the temperature sensor 44, the controller 45 instructs the valve drive unit 57 about the swing position of the swing valve 56 necessary to achieve the desired exhaust gas temperature. . Therefore, in the engine system 10, the exhaust gas temperature is feedback-controlled. Thus, the temperature adjusting device 42, the temperature sensor 44, and the controller 45 jointly constitute an “EGR control device” described in the claims.

  In the temperature adjusting device 42 described above, the swing shaft 84 of the swing valve 56 extends in the cooling passage 75, so that the swing shaft 84 is exposed to the low-temperature exhaust gas cooled by the cooling passage 75. Will be. Thereby, it is possible to suppress the temperature of the bearings 78 and 79 and the seal member 80 from rising due to the heat of the exhaust gas transmitted through the swing shaft 84.

  Further, in the temperature adjusting device 42, a swing shaft 84 is provided on the opposite side of the outlet portion 73 of the bypass passage 81 across the partition wall 58 that partitions the outlet portion 72 of the cooling passage 75 and the outlet portion 73 of the bypass passage 81. The downstream end portion 87 of the partition wall 58 is bent toward the swing shaft 84 side. Therefore, the high-temperature exhaust gas flowing through the bypass passage 81 is sufficiently blocked by the partition wall 58 and hardly reaches the periphery of the swing shaft 84, and the effect of suppressing the temperature rise of the bearings 78 and 79 and the seal member 80 is enhanced. .

  Further, in the temperature adjusting device 42, when the swing valve 56 opens the bypass passage 81, the cooling passage 75 and the outlet 83 communicate with each other through the gap 90 between the swing shaft 84 and the partition wall 58. Therefore, even if the bypass passage 81 is opened, the low-temperature exhaust gas cooled by the cooling passage 75 flows through the gap 90, so that the high-temperature exhaust gas flowing out from the bypass passage 81 to the outlet 83 swings. It becomes difficult to reach the periphery of the shaft 84. Therefore, the effect of suppressing the temperature rise of the bearings 78 and 79 and the seal member 80 is enhanced.

  Furthermore, in the temperature adjusting device 42, when the swing valve 56 closes the bypass passage 81, the valve main body 85 protruding outward in the radial direction of the swing shaft 84 is locked by the downstream end 87 of the partition wall 58. As a result, the high-temperature exhaust gas flowing through the bypass passage 81 is blocked by the valve body 85 and hardly reaches the periphery of the swing shaft 84. Therefore, the effect of suppressing the temperature rise of the bearings 78 and 79 and the seal member 80 is enhanced.

  Thus, in the temperature adjusting device 42 in which the temperature rise of the bearings 78 and 79 and the seal member 80 can be effectively suppressed, the elements 78, 79, and 80 are hardly melted by heat received from the exhaust gas. It is possible to prevent malfunctions such as locking and deterioration of sealing performance. Further, since the amount of thermal expansion due to heat received from the exhaust gas is reduced in the bearings 78 and 79, the clearance between the swing shaft 84 and the bearings 78 and 79 can be set small to improve vibration resistance.

Such an operation failure and the effect of preventing the deterioration of sealing performance and the effect of improving the vibration resistance can be obtained only by arranging the swing shaft 84 so as to extend in the cooling passage 75 without using a cooling device or the like. Therefore, it is possible to reduce the size and the cost.
In addition, in the temperature adjusting device 42, the downstream end 87 of the partition wall 58 functions to lock the swing valve 56 when the bypass passage 81 is closed, so a new part that exhibits the locking function is added. There is no need. Therefore, it is possible to reduce the number of parts and thus reduce the cost.

( First reference example )
FIG. 7 shows a main part of the temperature adjusting device 100 according to the first reference example of the present invention. Components that are substantially the same as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
In the temperature adjusting device 100, when the swing valve 110 closes the cooling passage 75 in the first swing position, these elements are arranged such that the downstream end 121 of the partition wall 120 locks the protrusion 111 of the swing valve 110. 121 and 111 are formed.

  In the temperature adjusting device 100, when the swing valve 110 opens both the cooling passage 75 and the bypass passage 81 at the swing position between the first swing position and the second swing position, Similarly, the cooling passage 75 and the outlet 83 communicate with each other through the gap 90, and the temperature rise of the swing shaft 84 is suppressed.

  On the other hand, when the oscillating valve 56 closes the cooling passage 75 at the first oscillating position shown in FIG. 7, the downstream end 121 of the partition wall 120 engages the protrusion 111 of the oscillating valve 110 so that the gap 90 The communication between the cooling passage 75 and the outlet 83 is cut off. Therefore, when only the bypass passage 81 is opened to guide the hot exhaust gas to the intake system 20, it is possible to prevent the temperature reduction of the exhaust gas that closes the cooling passage 75 and leads to the intake system 20. As described above, the protrusion 111 corresponds to a “communication blocking unit” recited in the claims.

  Further, in the temperature adjusting device 100, when the cooling passage 75 is closed, the downstream side end portion 87 of the partition wall 58 exhibits a function of locking the swing valve 56. Therefore, a new part that exhibits the locking function is added. There is no need. Therefore, it is possible to reduce the number of parts and thus reduce the cost.

( Second embodiment )
FIG. 8 shows a main part of the temperature adjustment device 150 according to the second embodiment of the present invention. Components that are substantially the same as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
In the temperature adjustment device 150, the swing shaft 171 of the swing valve 170 extends downstream from the downstream end 161 of the partition wall 160 in the cooling passage 75. Therefore, the swing shaft 171 is not located on the opposite side of the bypass passage 81 from the outlet portion 73 across the partition wall 160, and the length of the partition wall 160 is shortened in the exhaust flow direction. Therefore, since the material cost of the partition 160 is reduced, the cost reduction effect is promoted.

Although a plurality of embodiments and reference examples of the present invention have been described above, the present invention should not be construed as being limited to those embodiments.
For example , in the embodiment and the reference example , the seal member that seals between the bearing and the swing shaft of the swing valve is provided. However, such a seal member may not be provided.

It is a partially cutaway side view which shows the principal part of the temperature control apparatus by 1st embodiment. It is a mimetic diagram showing an engine system by a first embodiment. It is a partially notched front view which shows the temperature control apparatus by 1st embodiment. It is sectional drawing which shows the principal part of the temperature control apparatus by 1st embodiment. It is sectional drawing for demonstrating the action | operation of the temperature control apparatus by 1st embodiment. It is sectional drawing for demonstrating the action | operation of the temperature control apparatus by 1st embodiment. It is sectional drawing which shows the principal part of the temperature control apparatus by a 1st reference example . It is sectional drawing which shows the principal part of the temperature control apparatus by 2nd embodiment .

Explanation of symbols

10 engine system, 12 engine, 20 intake system, 30 exhaust system, 40 EGR system, 42, 100, 150 temperature adjustment device (EGR control device), 44 temperature sensor (EGR control device), 45 controller (EGR control device), 51 Introducing section, 52 Cooling section, 53 Bypass section, 54 Valve support section, 55 Deriving section, 56, 110, 170 Oscillating valve, 57 Valve driving section, 58, 120, 160 Partition, 60 Inlet, 61 Cooling case, 66 gas pipe, 69 first passage (cooling passage), 70 second passage (bypass passage), 72 third passage, outlet portion (cooling passage), 73 fourth passage, outlet portion (bypass passage), 75 cooling passage, 78, 79 Bearing, 80 Seal member, 81 Bypass passage, 83 Outlet, 84, 171 Oscillating shaft, 85 Valve body, 86 Projection, 87, 121, 161 Downstream side Parts, 90 gaps, 111 projections (connection cutoff unit)

Claims (7)

An exhaust gas recirculation control device that controls the temperature of exhaust gas that is recirculated by being led to an intake system of an internal combustion engine,
A cooling passage for circulating the exhaust gas while cooling,
A bypass passage that bypasses the cooling passage and distributes exhaust gas;
A partition partitioning the outlet portion of the cooling passage and the outlet portion of the bypass passage;
In the first swing position, the outlet portion of the cooling passage is closed and the outlet portion of the bypass passage is opened. In the second swing position, the outlet portion of the cooling passage is opened and the outlet portion of the bypass passage is closed. A swing valve that opens both outlets of the cooling passage and the bypass passage between a swing position and the second swing position;
A bearing for supporting a swing shaft of the swing valve;
An outlet for communicating exhaust gas to the intake system, communicating with a passage having an outlet portion open among the cooling passage and the bypass passage;
The swing shaft extends in the cooling passage, the swing shaft and the partition wall form a gap in a direction perpendicular to the flow of exhaust gas, and the swing valve is in the first swing position. An exhaust gas recirculation control device, wherein exhaust gas in the cooling passage flows through the gap.   The exhaust gas recirculation control device according to claim 1, further comprising a seal member that seals between the swing shaft and the bearing.   3. The exhaust gas recirculation control device according to claim 1, wherein the swing shaft is provided on a side opposite to an outlet portion of the bypass passage with the partition wall interposed therebetween.   The exhaust gas recirculation control device according to claim 3, wherein a downstream end portion of the exhaust gas flow in the partition wall is bent toward the swing shaft.   5. The exhaust according to claim 3, wherein the swing valve communicates the cooling passage with the outlet through a gap between the swing shaft and the partition when the bypass passage is opened. Gas recirculation control device. The downstream end of the exhaust gas flow in said partition wall, according to any one of claims 3-5, characterized in that the swing valve is engaged with the swing valve when closing said bypass passage Exhaust gas recirculation control device. The swing valve has a valve body that protrudes radially outward from the swing shaft,
The exhaust gas recirculation control device according to claim 6 , wherein when the swing valve closes the bypass passage, the downstream end of the partition wall engages the valve main body.

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