JP2012159002A - Exhaust gas recirculation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust gas recirculation system capable of easily adjusting the temperature of exhaust gas to be led to an intake passage while controlling deposits.SOLUTION: The exhaust gas recirculation system includes an exhaust manifold 42 communicating with combustion chambers 21-24 of an internal combustion engine 20, and constituting a part of an exhaust system 40, an exhaust gas recirculation passage 120 for leading a part of exhaust gas G from the exhaust system 30 to an intake passage 38, a catalyst device 70 formed in the exhaust gas recirculation passage 120, a cover member 90 for covering an exhaust gas manifold 42 and the catalyst device 70, an opening/closing plate 101 for adjusting the opening of an opening 91 by opening/closing the opening 91 formed in the cover member 90, a driving device 102 for adjusting the temperature of the exhaust gas G to be led to the intake passage 38 by controlling the opening/closing plate 101, a rotational angle detection sensor 102a, and a control means 170. The control means 170 controls the driving device 102 on the basis of the result of detection by the rotational angle detection sensor 102a.

Description

  The present invention relates to an exhaust gas recirculation device used in, for example, an internal combustion engine mounted on a vehicle.

  Conventionally, in order to reduce NOx (nitrogen oxides) in exhaust discharged from an internal combustion engine, there is an exhaust gas recirculation device (exhaust gas recirculation device) that guides part of the exhaust to an intake passage. Since a part of the exhaust gas is supplied to the combustion chamber, the temperature rise in the combustion chamber is suppressed, so that the generation of NOx is suppressed.

  On the other hand, depending on the operating state of the internal combustion engine, unburned fuel and soot may be included in the exhaust gas. By combining unburned fuel and soot contained in the exhaust gas, deposits are deposited in the flow path of the exhaust gas in the exhaust gas recirculation device.

  For this reason, the exhaust gas recirculation device includes a catalyst for purifying exhaust gas. The catalyst exhibits its performance sufficiently when the temperature rises to the activation temperature. In order to quickly raise the temperature of the catalyst to the activation temperature, a technique has been proposed in which a housing housing the catalyst is brought into contact with the exhaust manifold (for example, see Patent Document 1).

JP 2006-257905 A

  On the other hand, electronic components such as a throttle valve and a temperature sensor are provided in the intake passage and the exhaust gas recirculation passage. It is not preferable that the temperature of the exhaust gas led to the intake passage exceeds the heat resistance temperature of these parts. In order to avoid deterioration of exhaust gas discharged from the internal combustion engine, in order to keep the internal combustion engine in an optimal operating state at all times, the intake air temperature is detected and the fuel injection timing, the injection amount, the number of injections, and the ignition timing are accordingly detected. In addition, a plurality of parameters such as adjustment of the intake air amount and exhaust gas recirculation amount are controlled simultaneously, and the control is complicated and the control items are likely to vary.

  Therefore, an object of the present invention is to provide an exhaust gas recirculation device that can easily adjust the temperature of exhaust gas guided to an intake passage while suppressing deposits.

  An exhaust gas recirculation device according to a first aspect of the present invention includes an exhaust passage that communicates with a combustion chamber of an internal combustion engine and constitutes a part of an exhaust system, and an exhaust gas recirculation passage that guides a part of exhaust from the exhaust system to an intake passage. The opening degree of the opening is adjusted by opening and closing the opening formed in the catalyst device formed in the exhaust gas recirculation passage, the cover member covering a part of the exhaust passage and the catalyst device, and the cover member An opening / closing door member that controls the temperature of the exhaust gas that is guided to the intake passage by controlling the opening / closing door member, and a control unit that controls the temperature adjustment means.

  An exhaust gas recirculation device according to a second aspect of the present invention comprises the temperature increase determination means for determining whether or not the catalyst device needs to be increased in the invention according to the first aspect. The control means controls the opening / closing door member to reduce the opening of the opening when the temperature increase determination means determines that the catalyst apparatus needs to be heated.

  The exhaust gas recirculation apparatus according to a third aspect of the present invention is the exhaust gas recirculation apparatus according to the second aspect, wherein the temperature rise determination means includes a refrigerant temperature detection means for detecting a temperature of a refrigerant that cools the combustion chamber, Based on the temperature of the refrigerant detected by the temperature detection means, it is determined whether the catalyst device needs to be heated or not.

  The exhaust gas recirculation device according to a fourth aspect of the present invention is the exhaust gas recirculation apparatus according to any one of the first to third aspects, wherein the temperature of the air-fuel mixture of the air supplied to the combustion chamber and the exhaust gas A gas mixture temperature detecting means is provided. The control means controls the opening of the opening so that the temperature of the air-fuel mixture becomes a predetermined temperature.

  The exhaust gas recirculation device according to a fifth aspect of the present invention is the exhaust gas recirculation device according to the fourth aspect, wherein the exhaust gas recirculation passage is provided downstream of the catalyst device to cool the exhaust gas, and the exhaust gas recirculation passage includes the cooling device. A detour passage provided downstream of the catalyst device and detouring the cooling device. The control means controls the opening degree of the opening and the flow rate of the exhaust gas flowing through the bypass passage so that the temperature of the air-fuel mixture becomes the predetermined temperature.

  In the exhaust gas recirculation device of the invention according to claim 6, in the invention according to claim 5, the control means minimizes the opening of the opening when the temperature of the air-fuel mixture is lower than the predetermined temperature. Later, the flow rate of the exhaust gas flowing through the bypass passage is changed.

  The exhaust gas recirculation device according to a seventh aspect of the present invention is the exhaust gas recirculation apparatus according to the sixth aspect, wherein the control means is configured such that the flow rate of the exhaust gas flowing through the bypass passage when the temperature of the air-fuel mixture is higher than the predetermined temperature. After the value is set to 0, the opening degree of the opening is changed.

  ADVANTAGE OF THE INVENTION According to this invention, the exhaust gas recirculation apparatus which can adjust easily the temperature of the exhaust_gas | exhaustion guide | induced to an intake passage can be provided, suppressing a deposit.

1 is a schematic diagram showing an internal combustion engine system including an exhaust gas recirculation device according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of the internal combustion engine system taken along line F2-F2 shown in FIG. The top view which shows the state which looked at the cover member of the exhaust gas recirculation apparatus shown by FIG. 1 from the upper side along the vehicle body up-down direction. Sectional drawing of the exhaust gas recirculation apparatus shown along the F4-F4 line shown in FIG. Sectional drawing which shows the state which cut | disconnected the exhaust gas recirculation apparatus shown by FIG. 2 similarly to FIG. 4, and shows the maximum open state of opening. The flowchart which shows operation | movement of the exhaust gas recirculation apparatus shown by FIG. Schematic which shows an internal combustion engine system provided with the exhaust gas recirculation apparatus which concerns on the 2nd Embodiment of this invention. The flowchart which shows operation | movement of the exhaust gas recirculation apparatus shown by FIG. Sectional drawing which expands and shows the opening and opening-and-closing plate which were shown by FIG. Schematic which shows an internal combustion engine system provided with the exhaust gas recirculation apparatus which concerns on the 3rd Embodiment of this invention. Schematic which shows an internal combustion engine system provided with the exhaust gas recirculation apparatus which concerns on the 4th Embodiment of this invention. 12 is a flowchart showing the operation of the exhaust gas recirculation apparatus shown in FIG. Schematic which shows an internal combustion engine system provided with the exhaust gas recirculation apparatus which concerns on the 5th Embodiment of this invention. 14 is a flowchart showing the operation of the exhaust gas recirculation device shown in FIG.

  An exhaust gas recirculation apparatus according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram showing an internal combustion engine system 10. As shown in FIG. 1, the internal combustion engine system 10 includes an internal combustion engine 20, an intake system 30, an exhaust system 40, and an exhaust gas recirculation device 50. The internal combustion engine 20 is mounted on the automobile 1. The automobile 1 is an example of a vehicle including an exhaust gas recirculation device.

  In FIG. 1, the outline of the engine room 2 of the automobile 1 is indicated by a two-dot chain line. The automobile 1 can run by driving the wheels with a rotational force obtained from a crankshaft (not shown) of the internal combustion engine 20. The internal combustion engine 20 is a four-cylinder reciprocating internal combustion engine as an example in the present embodiment, and includes combustion chambers 21 to 24. The internal combustion engine 20 includes a cylinder head 25 and a cylinder block (not shown). In FIG. 1, the combustion chambers 21 to 24 are indicated by dotted lines. Inside the internal combustion engine 20, a refrigerant flow path is formed through which a refrigerant that cools the combustion chambers 21 to 24 flows. In the present embodiment, the cooling water C is used as an example of the refrigerant.

  The intake system 30 includes an intake passage 38 that guides air or a mixture of air and exhaust G that is returned to the intake system 30 by an exhaust gas recirculation device 50 described later, and a throttle valve 31 to the combustion chambers 21 to 24. . The intake passage 38 includes an intake manifold 32. The intake manifold 32 is fixed to the cylinder head 25 and includes branch portions 33 to 36 communicating with the combustion chambers 21 to 24 and a junction portion 37 where the branch portions 33 to 36 merge. The junction part 37 is a part where the branch parts 33 to 36 become one.

  A throttle valve 31 is provided upstream of the intake manifold 32 in the intake passage 38. The throttle valve 31 adjusts the amount of air supplied to the combustion chambers 21 to 24 or a mixture of air and exhaust G by adjusting the opening degree.

  The exhaust system 40 includes an exhaust passage 41 that communicates with the combustion chambers 21 to 24. The exhaust passage 41 includes an exhaust manifold 42. The exhaust manifold 42 communicates with the combustion chambers 21-24. The exhaust manifold 42 includes branch portions 43 to 46 that communicate with the combustion chambers 21 to 24 and a merge portion 48 where the branch portions 43 to 46 merge. The merge part 48 is a part where the branch parts 43 to 46 become one. In FIG. 1, the junction 48 is shown surrounded by a two-dot chain line. Further, in FIG. 1, in the exhaust manifold 42, the joining portion 48 and a range F21 indicated by a two-dot chain line in the vicinity of the joining portion 48 are enlarged. Also in the range 21, the junction 48 is indicated by a two-dot chain line.

  In FIG. 1, only a part of the portion 41 a other than the exhaust manifold 42 in the exhaust passage 41 is shown. The exhaust manifold 42 will be specifically described later.

  The internal combustion engine 20 is disposed and fixed so that the exhaust manifold 42 is positioned on the rear side of the vehicle body with respect to the intake manifold 32 and the direction in which the combustion chambers 21 to 24 are aligned is along the vehicle width direction.

  As shown in FIG. 1, the exhaust gas recirculation device 50 guides a part of the exhaust gas G discharged from the combustion chambers 21 to 24 to the intake system 30. FIG. 2 is a cross-sectional view of the internal combustion engine system 10 taken along line F2-F2 shown in FIG. FIG. 2 shows the inside of the cover member 90 of the exhaust gas recirculation device 50.

  As shown in FIGS. 1 and 2, the exhaust gas recirculation device 50 includes an exhaust manifold 42, an upstream exhaust gas recirculation passage 60, a catalyst device 70, a downstream exhaust gas recirculation passage 80, a cover member 90, and the temperature of the exhaust G. And control means 170 for adjusting.

  The upstream exhaust gas recirculation passage 60 communicates with the exhaust manifold 42 and also communicates with the catalyst device 70. The downstream side exhaust gas recirculation passage 80 communicates with the catalyst device 70 and also communicates with the intake passage 38. The upstream exhaust recirculation passage 60, the catalyst device 70, and the downstream exhaust recirculation passage 80 constitute an exhaust recirculation passage 120 that guides the exhaust G to the intake system 30.

  As shown in FIGS. 1 and 2, the exhaust manifold 42 has branch portions 43 to 46 that are arranged in the vehicle width direction, and therefore has a shape that is long in the vehicle width direction. The merging portion 48 is disposed at the center along the direction in which the branch portions 43 to 46 are arranged in the exhaust manifold 42 (the vehicle width direction in the present embodiment).

  The upstream side exhaust recirculation passage 60 includes a first connection passage portion 61 and an upstream side bellows tube member 62. The 1st connection channel | path part 61 is formed with a pipe member, for example. The upstream end 63 of the first connection passage portion 61 communicates with a branch portion 46 disposed at one end of the plurality of branch portions 43 to 46 of the exhaust manifold 42 in the direction in which the branch portions 43 to 46 are arranged. Further, the first connecting passage portion 61 is fixed to the wall portion on the vehicle body upper side of the branch portion 46.

  Here, the vehicle body vertical direction A will be described. The vehicle body vertical direction A is a direction parallel to the direction in which gravity acts when a vehicle (the automobile 1 in this embodiment) including the exhaust gas recirculation device 50 is arranged on a plane perpendicular to the direction in which gravity acts. . The direction in which the gravity acts is the downward direction, and the direction against the direction in which the gravity works is the upward direction.

  Returning to the description of the exhaust gas recirculation device 50. The first connecting passage portion 61 extends in the direction in which the branch portions 43 to 46 are arranged above the exhaust manifold 42 in the vehicle body. The entire first connecting passage portion 61 overlaps the exhaust manifold 42 in the vehicle body vertical direction A, as shown in FIGS.

  The upstream side bellows tube member 62 communicates with the downstream end of the first connection passage portion 61. The upstream side bellows tube member 62 is disposed above the exhaust manifold 42 along the vertical direction A of the vehicle body. The upstream side bellows tube member 62 extends in the direction in which the branch portions 43 to 46 are arranged. The entire upstream bellows tube member 62 overlaps the exhaust manifold 42 along the vehicle body vertical direction A. Since the upstream side bellows tube member 62 has a bellows shape, the upstream side bellows tube member 62 can expand and contract in the extending direction. The downstream end of the upstream side bellows tube member 62 communicates with the catalyst device 70.

  The catalyst device 70 is disposed above the exhaust manifold 42 along the vertical direction A of the vehicle body. The catalyst device 70 is not in contact with the exhaust manifold 42. The catalyst device 70 includes a housing 71, a catalyst 72, and a plurality of fins 73. The housing 71 includes a main body 71a that houses a catalyst 72 described later, an upstream communication portion 71b that communicates with the upstream bellows tube member 62, and a downstream communication portion 71c that communicates with a downstream exhaust recirculation passage 80 described later. It has. The main body 71a has a cylindrical shape, for example.

  The catalyst 72 is accommodated in the main body 71 a of the housing 71. In FIG. 2, a part of the main body 71a is cut off, and a part of the catalyst 72 accommodated therein is shown. The upstream communication portion 71 b communicates with the downstream end of the upstream side bellows tube member 62. The substantially entire catalyst device 70 (housing 71) overlaps the exhaust manifold 42 along the vehicle body vertical direction A. The entire catalyst device 70 may overlap the exhaust manifold 42 in the vehicle body vertical direction A. The substantially entire catalyst 72 overlaps the exhaust manifold 42 in the vehicle body vertical direction A. The entire catalyst 72 may overlap the exhaust manifold 42 in the vehicle body vertical direction A. The upstream end 74 of the main body 71 a of the housing 71 overlaps the merging portion 48 of the exhaust manifold 42 along the vehicle body vertical direction A. For this reason, the upstream end of the catalyst 72 overlaps the exhaust manifold 42 in the vertical direction A of the vehicle body.

  The plurality of fins 73 have a plurality of through holes into which the housing 71 is fitted. The entire edge of the through hole is in contact with the outer peripheral surface of the housing 71. Each fin 73 extends in the vertical direction A of the vehicle body and is spaced apart from each other in the direction in which the housing 71 extends. The plurality of fins 73 are equally disposed on the main body 71a. Each fin 73 does not contact the exhaust manifold 42.

  A gap between the fin 73 and the exhaust manifold 42 will be described. When the internal combustion engine 20 starts operation and the exhaust gas G flows in the exhaust manifold 42 and the catalyst device 70, the exhaust manifold 42 and the housing 71 are thermally expanded by the heat of the exhaust G. The gaps between the fins 73 and the exhaust manifold 42 when the housing 71 and the exhaust manifold 42 are not thermally expanded cause the fins 73 and the exhaust manifold 42 to thermally expand during operation of the internal combustion engine 20. However, each fin 73 and the exhaust manifold 42 are set so as not to contact each other. This gap can be obtained by experiments or the like.

  As shown in FIG. 1, the downstream side exhaust recirculation passage 80 includes a downstream side bellows tube member 81 and a second connection passage portion 82. As shown in FIG. 2, the upstream end of the downstream side bellows tube member 81 communicates with the downstream side communication portion 71 c of the housing 71 of the catalyst device 70. As shown in FIGS. 1 and 2, the downstream side bellows tube member 81 is disposed above the vehicle body along the vehicle body vertical direction A with respect to the exhaust manifold 42. The substantially entire downstream bellows tube member 81 overlaps the exhaust manifold 42 along the vehicle body vertical direction A. The entire downstream side bellows tube member 81 may overlap the exhaust manifold 42 along the vehicle body vertical direction A, like the upstream side bellows tube member 62. The downstream bellows tube member 81 extends along the direction in which the branch portions 43 to 46 extend. The downstream bellows tube member 81 can be expanded and contracted in the extending direction.

  The 2nd connection channel part 82 is formed with a pipe member, for example. The second connecting passage portion 82 communicates with the downstream end of the downstream side bellows tube member 81. As shown in FIG. 1, the second connecting passage 82 communicates downstream of the throttle valve 31 and upstream of the intake manifold 32 in the intake system 30.

  In FIG. 1, the cover member 90 is indicated by a two-dot chain line. FIG. 3 is a plan view of the cover member 90 as viewed from above along the vehicle body vertical direction A. FIG. As shown in FIGS. 1 to 3, the cover member 90 includes the entire exhaust manifold 42, the entire upstream exhaust recirculation passage 60, the entire downstream bellows tube member 81, and the upstream of the second connection passage portion 82. Covers the end. 4 is a cross-sectional view of the exhaust gas recirculation device 50 taken along line F4-F4 shown in FIG. In FIG. 4, the intake system 30 is omitted.

  As shown in FIGS. 1 to 4, the cover member 90 includes an upper wall portion 92 located on the upper side along the vehicle body vertical direction A, and a peripheral wall portion 93. The cover member 90 is fixed to, for example, the exhaust manifold 42 by a bracket (not shown).

  The peripheral wall portion 93 includes a first vertical wall portion 94 disposed between the catalyst device 70 and the internal combustion engine 20, and a second vertical wall portion disposed on the opposite side of the internal combustion engine 20 across the catalyst device 70. 95, and third and fourth vertical wall portions 96, 97 that connect the first and second vertical wall portions 94, 95 to each other.

  As shown in FIG. 4, the first vertical wall portion 94 extends upward from the upper end along the vehicle body vertical direction A of the exhaust manifold 42. The gap between the lower end of the first vertical wall portion 94 and the exhaust manifold 42 is small. Alternatively, the lower end of the first vertical wall portion 94 may be fixed to the exhaust manifold 42 and have no gap. The second to fourth vertical wall portions 95 to 97 extend along the vehicle body vertical direction A to substantially the same position as the lower end of the exhaust manifold 42. Alternatively, the second to fourth vertical wall portions 95 to 47 may extend along the vehicle body vertical direction A to the same position as the lower end of the exhaust manifold 42 or a position below the lower end of the exhaust manifold 42. The gap between the second vertical wall portion 95 and the exhaust manifold 42 is small. Alternatively, the second vertical wall portion 95 is in contact with the exhaust manifold 42, and therefore there may be no gap between the exhaust manifold and the second vertical wall portion 95.

  Similarly, there may be no gap between the third and fourth vertical wall portions 96 and 97 and the exhaust manifold 42. In other words, there may be no gap between the cover member 90 and the exhaust manifold 42.

  The upper wall portion 92 is provided at the upper end of the peripheral wall portion 93 and covers the upper end of the peripheral wall portion 93. As shown in FIGS. 2 and 3, the upper wall 92 is provided with an opening 91. The opening 91 has a size that overlaps at least a part of the catalyst 72 of the catalyst device 70 in the vertical direction A of the vehicle body. In the present embodiment, the opening 91 is a long hole that is long in the direction in which the branch portions 43 to 46 are arranged.

  The control means 170 includes a refrigerant temperature detection sensor 180 that detects the temperature of the refrigerant L, an opening / closing device 100 that opens and closes an opening 91 formed in the cover member 90, and a control unit 190. The refrigerant temperature detection sensor 180 is provided in the internal combustion engine 20.

  The opening / closing device 100 opens and closes the opening 91. As an example, the opening / closing device 100 includes an opening / closing plate 101 covering the opening 91, a state in which the opening 91 is opened by changing the posture (position) of the opening / closing plate 101, and a state in which the opening 91 is covered and closed by the opening / closing plate 101. And a switchable drive device 102. The opening / closing plate 101 is an example of an opening / closing door member referred to in the present invention.

  The opening / closing plate 101 has a size slightly smaller than the opening 91 when viewed in the vehicle body vertical direction A. The opening / closing plate 101 is provided with a rotating shaft 103. The rotating shaft 103 extends in the direction in which the branch portions 43 to 46 are arranged. Both end portions 104 and 105 of the rotating shaft 103 come out of the opening 91 when the opening / closing plate 101 is set in the opening 91. The rotation shaft 103 is disposed at the center of the opening / closing plate 101 along a direction orthogonal to the longitudinal direction. Bearing portions 106 and 107 that rotatably support both end portions 104 and 105 of the rotating shaft 103 are provided at the edge portion of the opening 91.

  The opening degree of the opening 91 is adjusted by rotating the opening / closing plate 101 around the rotation shaft 103 in a state where both end portions 104 and 105 of the rotation shaft 103 are supported by the bearing portions 106 and 107. Moreover, the opening 91 switches between the maximum open state P1 and the minimum open state P2. The state shown in FIGS. 3 and 4 shows the minimum open state P <b> 2 of the opening 91. FIG. 5 shows a state in which the exhaust gas recirculation device 50 is cut in the same manner as in FIG. 4, and shows a maximum open state P1 of the opening 91.

  The maximum open state P1 is a state where the area that is not covered by the opening / closing plate 101 in the opening 91 is maximized, and the opening degree of the opening 91 is maximized. In the maximum open state P1, the opening / closing plate 101 is in the vertical direction A of the vehicle body. The minimum open state P2 is a state in which the opening 91 is covered with the opening / closing plate 101 and closed most when the opening / closing plate 101 is in a posture along the longitudinal direction of the vehicle body. In other words, the opening 91 is in a fully closed state. In the minimum opening state P2, the opening degree of the opening 91 is minimum. In the present embodiment, the most closed state is a gap between the opening 91 and the opening / closing plate 101 as shown in FIG. 4, and the opening 91 is not completely sealed but is most covered. Indicates broken state.

  The drive device 102 is an actuator that rotationally drives the rotary shaft 103. In this embodiment, an electric motor is used as an example of an actuator. The rotating shaft 103 is rotated by the driving device 102. Further, the driving device 102 includes a rotation angle detection sensor 102 a that detects the rotation angle of the rotation shaft 103.

  As shown in FIGS. 1 and 2, the control unit 190 is connected to the refrigerant temperature detection sensor 180, the drive device 102, and the rotation angle detection sensor 102 a.

  The control unit 190 transmits the detection result of the refrigerant temperature detection sensor 180. The refrigerant temperature detection sensor 180 is an example of the refrigerant temperature detection means referred to in the present invention. Control unit 190 detects the temperature of cooling water C based on the detection result of refrigerant temperature detection sensor 180 and determines whether the warm-up operation of internal combustion engine 20 has been completed based on the temperature of cooling water C. .

  The control unit 190 and the refrigerant temperature detection sensor 180 determine whether or not the temperature of the catalyst device 70 needs to be increased based on the temperature of the cooling water C. The control unit 190 and the refrigerant temperature detection sensor 180 constitute an example of a temperature rise determination unit referred to in the present invention.

  The threshold value Twh of the cooling water C temperature for determining completion of the warm-up operation is stored in the control unit 190 in advance. The control unit 190 determines that the warm-up operation of the internal combustion engine 20 is not completed when the temperature of the cooling water C is equal to or lower than the threshold value Twh. If the temperature of the internal combustion engine 20 is higher than Twh, it is determined that the warm-up operation of the internal combustion engine 20 has been completed. The temperature threshold value Twh for determining the completion of the warm-up operation can be obtained in advance by experiments or the like. The control part 190 comprises an example of the control means said by this invention.

  The control unit 190 controls the driving device 102 to rotate the opening / closing plate 101. The control unit 190 transmits the detection angle of the rotation angle detection sensor 102a. The control unit 190 detects the attitude of the opening / closing plate 101 based on the result of the rotation angle detection sensor 102a. Thus, the control unit 190 can obtain the opening degree of the opening 91. More specifically, the control unit 190 can obtain whether the opening 91 is in the maximum open state P1 or the minimum open state P2. The opening degree of the opening 91 changes depending on the posture of the opening / closing plate 101. The opening degree of the opening 91 is determined in advance according to the posture of the opening / closing plate 101 and is stored in the control unit 190. The control unit 190 can obtain the opening degree of the opening 91 from the posture of the opening / closing plate 101. Further, the control unit 190 detects the start of operation and the completion of operation of the internal combustion engine 20. The drive device 102a and the rotation angle detection sensor 102a constitute a temperature adjusting means referred to in the present invention.

  Next, the operation of the exhaust gas recirculation device 50 will be described. FIG. 6 is a flowchart showing the operation of the exhaust gas recirculation device 50. First, the operation until the warm-up operation of the internal combustion engine 20 is completed after the internal combustion engine 20 starts operation will be described. Note that the warm-up operation is determined to be completed when the temperature of the cooling water C exceeds a threshold value Twh, which is a temperature at which completion of the warm-up operation is determined. An example of the operation described next is an operation when the temperature of the cooling water C is equal to or lower than the threshold value Twh.

  As shown in FIG. 6, in step ST1, it is determined whether or not the internal combustion engine 20 is driven. The control unit 190 detects the start and completion of the internal combustion engine 20 as described above. In this control, since the internal combustion engine 20 is driven, the control unit 190 determines that the internal combustion engine 20 is driven. Then, the process proceeds to step ST2.

  In step ST2, the control unit 190 determines whether or not the flag is 1. Immediately after the internal combustion engine 20, the flag is set to zero. When step ST2 is reached for the first time after the driving of the internal combustion engine 20 is started, the flag remains 0, so the control unit 190 determines that the flag is not 1. Then, the process proceeds to step ST3. In step ST3, the control unit 190 sets a flag to 1. Then, the process proceeds to step ST4.

  In step ST4, the control unit 190 controls the driving device 102 to rotate the opening / closing plate 101 and adjust the posture of the opening / closing plate 101 based on the detection result of the rotation angle detection sensor 102a to open the opening 91 in the minimum opening state P2. To. Then, the process proceeds to step ST5.

In step ST5, the control unit 190 determines whether or not the temperature of the cooling water C, which is a detection result of the refrigerant temperature detection sensor 180, is greater than a threshold value Twh for determining completion of the warm-up operation. In this state, since the temperature of the cooling water C is equal to or lower than the threshold value Twh, the process proceeds to step ST6. The fact that the temperature of the cooling water C is equal to or lower than the threshold value Twh needs to raise the temperature of the internal combustion engine 20. The controller 190 determines that the temperature of the cooling water C needs to be raised by raising the temperature of the catalyst device 70 and raising the temperature of the exhaust gas G in order to raise the temperature of the internal combustion engine 20. That is, it is determined that the temperature of the catalyst device 70 needs to be increased.

  In step ST6, the control unit 190 controls the driving device 102 and sets the opening 91 to the minimum open state P2 based on the detection result of the rotation angle detection sensor 102a. In the state where the temperature of the cooling water C does not exceed the threshold value Twh after the internal combustion engine 20 is started, the opening 91 is maintained in the minimum open state P2. In other words, the posture of the opening / closing plate 101 is maintained such that the opening 91 is maintained in the minimum open state P2. Then, the process returns to step ST1. Until the warm-up operation of the internal combustion engine 20 is completed, the operations in steps ST1 to ST6 are repeated. When step ST2 is reached for the second time after the start of driving of the internal combustion engine 20, the flag is set to 1 at that time, so the process proceeds from step ST2 to step ST5.

  While steps ST1, ST2, ST5, ST6 are repeated, the temperature of exhaust manifold 42 is increased by the heat of exhaust G. The air around the exhaust manifold 42 is heated by the heated exhaust manifold 42. Since the periphery of the exhaust manifold 42 is surrounded by the cover member 90, the heat of the exhaust manifold 42 is efficiently transferred to the air around the exhaust manifold 42 (air inside the cover member 90). For this reason, even when the temperature of the exhaust G is low, such as when the operation of the internal combustion engine 20 is started, the temperature inside the cover member 90 is quickly raised.

  The heated air flows upward along the vertical direction A of the vehicle body and strikes the catalyst device 70. When the heated air hits, the catalyst device 70 (catalyst 72) is heated. Even when the temperature of the exhaust G is low as at the start of operation, the catalyst 72 is efficiently heated. Further, when the radiant heat radiated from the exhaust manifold 42 reaches the catalyst device 70, the temperature of the catalyst 72 is increased. Moreover, since the surface area which receives the heat | fever in the catalyst apparatus 70 becomes large by providing the several fin 73 in the housing 71, the catalyst 72 is heated up earlier.

  The air heated by the exhaust manifold 42 and the radiant heat radiated from the exhaust manifold 42 raise the temperature of the catalyst 72 as described above, and the upstream exhaust recirculation passage 60 (inside the cover member 90) ( The temperature of the first connection passage portion 61 and the upstream side bellows tube member 62) and the downstream side exhaust gas recirculation passage 80 (a part of the second connection passage portion 82 and the downstream side bellows tube member 81) are increased.

  The upstream side bellows tube member 62 has a large surface area due to the bellows shape. For this reason, since the heat supplied from the exhaust manifold 42 is efficiently transmitted to the upstream side bellows tube member 62, the temperature is raised early. As a result, the temperature of the exhaust G guided to the catalyst 72 can be raised, so that the temperature of the catalyst 72 can be raised early.

  The first connection passage portion 61, the upstream side bellows tube member 62, the housing 71 of the catalyst device 70, the downstream side bellows tube member 81, and the second connection passage portion 82 are heated by being heated. Inflate. The upstream side bellows tube member 62 and the downstream side bellows tube member 81 include the first connection passage portion 61, the upstream side bellows tube member 62, the housing 71 of the catalyst device 70, the downstream side bellows tube member 81, and the second connection passage. The bellows shape can be expanded and contracted in the direction in which the portions 82 are arranged. For this reason, the upstream side bellows tube member 62 and the downstream side bellows tube member 81 expand and contract in accordance with the thermal expansion of each of the above components. This absorbs the thermal expansion of the component.

  A part of the exhaust G flowing through the exhaust manifold 42 is guided to the intake system 30 through the exhaust gas recirculation passage 120. The exhaust gas G flowing through the exhaust gas recirculation passage 120 is heated by passing through the upstream exhaust gas recirculation passage 60, the catalyst device 70, and the downstream exhaust gas recirculation passage 80, and is purified by passing through the catalyst 72. The exhaust gas G that has been heated and purified is guided to the combustion chambers 21 to 24.

  Next, the operation when the temperature of the cooling water C becomes higher than the threshold value Twh for determining the warm-up operation will be described. When the temperature of the cooling water C becomes higher than the threshold value Twh, the control unit 190 determines that the warm-up operation of the internal combustion engine 20 is completed in step ST5. Then, the process proceeds to step ST7.

  Since the internal combustion engine 20 does not need to be heated, the control unit 190 determines that the catalyst device 70 does not need to be heated. In step ST7, the control unit 190 controls the driving device 102 and adjusts the posture of the opening / closing plate 101 based on the detection result of the rotation angle detection sensor 102a, so that the opening 91 is in the maximum open state P1. Then, the process returns to step ST1. While the temperature of the cooling water C is higher than the threshold value Twh for determining completion of the warm-up operation, steps ST1, ST2, ST3, ST5 and ST7 are repeated.

  While the steps ST 1, ST 2, ST 3, ST 5, and ST 7 are repeated, the opening 91 is in the maximum open state P 1, whereby the air outside the cover member 90 is guided into the cover member 90 through the opening 91. The catalyst 72 is cooled by the air guided into the cover member 90. When the automobile 1 is traveling, the opening / closing plate 101 is in a posture along the vertical direction A of the vehicle body, so that the traveling wind W supplied from the front of the vehicle body hits the opening / closing plate 101 and enters the cover member 90. Led. Then, after flowing in the cover member 90, it is discharged from the opening 91. The opening / closing plate 101 functions as a guide for guiding the traveling wind into the cover member 90.

  When the temperature in the cover member 90 decreases, the thermal expansion of the components housed in the cover member 90 is released and the cover member 90 contracts. When the components in the cover member 90 are contracted, the upstream side bellows tube member 62 and the downstream side bellows tube member 81 are extended to absorb changes due to thermal expansion.

  Further, since the downstream side bellows tube member 81 has a bellows shape and has a large surface area, the exhaust G heated by the catalytic reaction heat by passing through the catalyst 72 is cooled by opening the opening 91. The exhaust G is led to the combustion chambers 21 to 24 after the density is improved by being cooled. Thus, the exhaust gas recirculation device 50 functions as a cooling device that cools the exhaust gas G when the opening 91 is in the maximum open state P1.

  If the driving of the internal combustion engine 20 is stopped during the operation until the warm-up operation is completed or during the operation after the warm-up operation is completed, the process proceeds from step ST1 to step ST8. In step ST8, the control unit 190 sets a flag to 0. Next, the operation of the control unit 190 is completed.

  In the exhaust gas recirculation device 50 configured as described above, the temperature of the exhaust gas G can be adjusted by adjusting the posture of the opening / closing plate 101. In other words, the exhaust gas recirculation device 50 can easily adjust the temperature of the exhaust gas guided to the intake passage while suppressing deposits.

  Further, the opening 91 is in the minimum open state P2 until the warm-up operation of the internal combustion engine 20 is completed based on the detection result of the refrigerant temperature detection sensor 180, whereby the temperature of the exhaust G is efficiently transferred to the catalyst 72 of the catalyst device 70. Since it can be transmitted, the catalyst 72 can be activated early. Furthermore, when the catalyst 72 is activated at an early stage, the intake system 30 can be prevented from being polluted due to the exhaust G guided to the intake passage 38.

  Even if the warm-up operation of the internal combustion engine 20 is not completed, the temperature of the exhaust gas G is raised by the exhaust gas recirculation device 50, so that the air guided to the combustion chambers 21 to 24 is mixed with the exhaust gas G. The temperature of the gas can be raised. As a result, the warm-up operation of the internal combustion engine 20 can be promoted.

  By promoting the warm-up operation of the internal combustion engine 20 by the exhaust gas recirculation device 50, the amount of fuel supplied to the combustion chambers 21 to 24 to increase the warm-up immediately after the operation of the internal combustion engine 20 is not increased. Alternatively, the amount of increase in fuel can be reduced. As a result, fuel consumption can be improved. Further, by eliminating the increase in the fuel supplied to the combustion chambers 21 to 24 as described above, or by reducing the increase amount of the fuel, the increase in the unburned fuel in the exhaust G is eliminated or the increase amount is reduced. Can be small.

  Further, after the warm-up operation of the internal combustion engine 20 is completed, the exhaust gas recirculation device 50 functions as a cooling device for cooling the exhaust gas G, whereby the density of the exhaust gas G supplied to the combustion chambers 21 to 24 can be increased. As a result, the generation of NOx can be suppressed.

  Further, since the exhaust manifold 42 and the catalyst 72 are accommodated inside the cover member 90, the temperature of the air around the exhaust manifold 42 is efficiently raised. Furthermore, when the catalyst device 70 overlaps the exhaust manifold 42 in the vehicle body vertical direction A, the air heated by the exhaust manifold 42 strikes the catalyst device 70. As a result, the heat of the exhaust manifold 42 can be efficiently used to raise the temperature of the catalyst device 70, so that the temperature of the catalyst 72 can be raised to the activation temperature early. Further, since the catalyst device 70 is not brought into direct contact with the exhaust manifold 42, it is possible to prevent the occurrence of a burden caused by bringing them into contact with each other.

  When the exhaust manifold 42 and the catalyst device 70 are in contact with each other, the burden referred to here is caused by the contact between the exhaust manifold 42 and the catalyst device 70 being pressed against each other by thermal expansion. This is a burden on the device 70.

  Furthermore, since substantially the entire catalyst device 70 overlaps the exhaust manifold 42 along the vehicle body vertical direction A, the heat of the exhaust manifold 42 is efficiently transmitted to the catalyst 72. Note that at least a part of the catalyst device 70 overlaps the exhaust manifold 42 in the vertical direction A of the vehicle body, so that the air heated by the exhaust manifold 42 efficiently hits the catalyst device 70, and the heat of the exhaust manifold 42 efficiently converts the catalyst. 72. Preferably, the entire catalyst device 70 overlaps in the vehicle body vertical direction A, so that the heat of the exhaust manifold 42 is more efficiently transmitted to the catalyst 72.

  Further, when the substantially entire catalyst 72 overlaps the exhaust manifold 42 in the vertical direction A of the vehicle body, the temperature of the catalyst 72 is raised efficiently. Note that at least a portion of the catalyst 72 overlaps the exhaust manifold 42 in the vertical direction A of the vehicle body, so that the heat of the exhaust manifold 42 is efficiently transmitted to the catalyst 72. Preferably, the entire catalyst 72 overlaps the exhaust manifold 42 in the vertical direction A of the vehicle body, so that the heat of the exhaust manifold 42 is transmitted to the catalyst 72 more efficiently.

  Further, by using the upstream side bellows tube member 62, the temperature of the exhaust gas G guided to the catalyst 72 can be raised to raise the temperature of the catalyst 72 early, and the thermal expansion of components in the cover member 90 can be absorbed. Can do.

  Further, by using the downstream side bellows tube member 81, the exhaust G heated by the reaction heat of the catalyst 72 can be cooled by opening the opening 91, and the thermal expansion of components in the cover member 90 can be reduced. Can be absorbed.

  Further, at least a part of the catalyst device 70 (in the present embodiment, the upstream end portion 74) overlaps the merging portion 48 of the exhaust manifold 42 in the vehicle body vertical direction A, whereby the catalyst 72 is efficiently heated. This point will be specifically described. Since the merge portion 48 is a portion where the branch portions 43 to 46 merge, the exhaust gas G always flows through the merge portion 48 during operation of the internal combustion engine 20. For this reason, the temperature of the catalyst 72 is efficiently raised by overlapping with the merging portion 48 in the vertical direction A of the vehicle body. Further, at least a part of the catalyst 72 (in the embodiment, the upstream end portion) overlaps with the merge portion 48 in the vehicle body vertical direction A, whereby the temperature of the catalyst 72 is efficiently increased.

  Further, since the plurality of fins 73 are provided in the housing 71 of the catalyst device 70, the heat of the exhaust manifold 42 is efficiently transmitted to the catalyst 72, so that the temperature of the catalyst 72 is efficiently increased. In the present embodiment, a plurality of fins 73 are provided, but the number of fins 73 may be one, for example. By providing at least one fin 73, the temperature of the catalyst 72 is increased efficiently. If a plurality of fins 73 are provided as in the present embodiment, the temperature of the catalyst 72 is increased more efficiently.

  Since the unburned fuel and CO in the exhaust G are low after the warm-up operation is completed, even if the temperature of the catalyst 72 becomes lower than the activation temperature due to cooling, the exhaust gas recirculation device 50 and the intake system 30 is not contaminated by the exhaust G.

  Next, an exhaust gas recirculation apparatus according to a second embodiment of the present invention will be described with reference to FIGS. In addition, the structure which has the same function as 1st Embodiment attaches | subjects the code | symbol same as 1st Embodiment, and abbreviate | omits description. The exhaust gas recirculation device of this embodiment further includes an air-fuel mixture temperature detection sensor. Furthermore, the operation of the control unit 190 is different from that of the first embodiment. These points are different from the first embodiment. Others are the same as the first embodiment. For this reason, in this embodiment, the exhaust gas recirculation device is denoted by reference numeral 50a. The control unit is denoted by reference numeral 190a.

  FIG. 7 is a schematic view showing the exhaust gas recirculation device 50a. As shown in FIG. 7 and as described above, the exhaust gas recirculation device 50a is provided with an air-fuel mixture temperature detection sensor 200 with respect to the exhaust gas recirculation device 50 described in the first embodiment, and is controlled. The difference is that a control unit 190 a is provided instead of the unit 190. In the present embodiment, instead of the control means 170, the control section 170a, the refrigerant temperature detection sensor 180, the opening / closing device 100, and the mixture temperature detection sensor 200 constitute a control means 170a.

  The mixture temperature detection sensor 200 is provided in the intake manifold 32 and detects the temperature in the intake manifold 32. The mixture temperature detection sensor 200 is an example of the mixture temperature detection means referred to in the present invention.

  The control unit 190 a is connected to the refrigerant temperature detection sensor 180, the drive device 102, the rotation angle detection sensor 102 a, and the mixture temperature detection sensor 200. The control unit 190a transmits the detection result of the refrigerant temperature detection sensor 180. Based on the detection result of the refrigerant temperature detection sensor 180, the controller 190a detects the temperature of the cooling water C and determines whether the warm-up operation of the internal combustion engine 20 has been completed. The threshold value Twh of the temperature of the cooling water C for determining completion of the warm-up operation is stored in advance in the control unit 190a. The controller 190a determines that the warm-up operation of the internal combustion engine 20 has not been completed when the temperature of the cooling water C is equal to or lower than Twh. If the temperature of the cooling water C is higher than Twh, it is determined that the warm-up operation of the internal combustion engine 20 has been completed. The temperature threshold value Twh for determining the completion of the warm-up operation can be obtained in advance by experiments or the like.

  The control unit 190a and the refrigerant temperature detection sensor 180 determine whether or not the temperature of the catalyst device 70 needs to be increased based on the temperature of the cooling water C. The control unit 190a and the refrigerant temperature detection sensor 180 constitute an example of a temperature rise determination unit referred to in the present invention.

  The control unit 190a controls the driving device 102 to rotate the opening / closing plate 101. The control unit 190a transmits the detection angle of the rotation angle detection sensor 102a. The control unit 190a detects the posture of the opening / closing plate 101 based on the result of the rotation angle detection sensor 102a. Thus, the control unit 190a can obtain the opening degree of the opening 91. More specifically, the control unit 190 can obtain whether the opening 91 is in the maximum open state P1 or the minimum open state P2. The opening degree of the opening 91 changes depending on the posture of the opening / closing plate 101. The opening degree of the opening 91 is determined in advance according to the posture of the opening / closing plate 101 and is stored in the control unit 190a. The control unit 190 a can obtain the opening degree of the opening 91 from the posture of the opening / closing plate 101. The control unit 190a detects the operation start and operation completion of the internal combustion engine 20.

  The control unit 190a transmits the detection result of the mixture temperature detection sensor 200. The control unit 190 a detects the temperature of the air-fuel mixture M in the intake manifold 32 based on the detection result of the air-fuel mixture temperature detection sensor 200.

  FIG. 8 is a flowchart showing the operation of the control unit 190a of this embodiment. The operation of the control unit 190a includes an operation until the warm-up operation of the internal combustion engine 20 is completed and an operation after the warm-up operation of the internal combustion engine 20 is completed.

First, an operation until the warm-up operation of the internal combustion engine 20 is completed will be described. As shown in FIG. 8, when the internal combustion engine 20 is driven, the control unit 190a determines that the internal combustion engine 20 has been started in step ST21. Next, the process proceeds to step ST22. In step ST22, the control unit 190a determines whether or not the flag is set to 1. The flag is set to 0 if the internal combustion engine 20 has just been started. Therefore, the control unit 190a determines that the flag is not set to 1. Then, the process proceeds to step ST23.

  The controller 190a sets a flag to 1 in step ST23. Then, the process proceeds to step ST24. In step ST24, the control unit 190a controls the driving device 102 to rotate the opening / closing plate 101 and adjusts the posture of the opening / closing plate 101 based on the result of the rotation angle detection sensor 102a to open the opening 91 in the minimum opening state P2. To. Then, the process proceeds to step ST25.

  In step ST25, the control unit 190a determines whether or not the warm-up operation of the internal combustion engine 20 has been completed. Specifically, control unit 190a determines whether or not the temperature of cooling water C is equal to or lower than threshold value Twh based on the detection result of refrigerant temperature detection sensor 180. In this description, since the warm-up operation of the internal combustion engine 20 is not completed, the process proceeds to step ST26.

  In step ST26, the controller 190a determines whether or not the temperature of the air-fuel mixture M is the optimum temperature during the warm-up operation. The optimum temperature during the warm-up operation is a temperature that is considered so that the temperature of the exhaust G supplied to the intake passage 38 is optimum for the intake system 30 during the warm-up operation of the internal combustion engine 20.

  More specifically, the intake system 30 is provided with an air-fuel mixture temperature detection sensor 200, a throttle valve 31, and the like. Some of these devices and components do not have a high maximum allowable temperature. In a state where the temperature of the air-fuel mixture M is the optimum temperature during the warm-up operation, the temperature of the exhaust G guided to the intake system 30 is lower than the upper limit temperature that the intake system 30 can withstand.

  In this embodiment, when the temperature of the air-fuel mixture M is not less than the lower limit temperature TiLc and not more than the upper limit temperature TiHc (including Tilc and TiHc), it is determined that the temperature is the optimum temperature during the warm-up operation. The optimum temperature during warm-up operation is an example of the predetermined temperature referred to in the present invention. If the temperature of the air-fuel mixture M has not reached the optimum temperature during the warm-up operation (less than the lower limit temperature TiLc), the process proceeds to step ST28 via step ST27.

  It is necessary to raise the temperature of the air-fuel mixture M that the temperature of the cooling water C is equal to or lower than the threshold value Twh and lower than the lower limit temperature TiLc. The controller 190a determines that it is necessary to raise the temperature of the exhaust gas G by raising the temperature of the catalyst device 70 in order to raise the temperature of the air-fuel mixture M. That is, the control unit 190a determines that the temperature of the catalyst device 70 needs to be increased.

  In step ST28, the controller 190a determines whether or not the opening degree of the opening 91 is minimum, that is, whether or not it is in the minimum open state P2. Specifically, the control unit 190a detects the attitude of the opening / closing plate 101 based on the detection result of the rotation angle detection sensor 102a, and detects the opening degree of the opening 91. Since the opening 91 is in the minimum opening state P2 in the operation state in which the internal combustion engine 20 has not started to reach the optimum temperature during the warm-up operation, the process returns to step ST21.

  As described above, when the warm-up operation is not completed after the internal combustion engine 20 is started and the temperature of the air-fuel mixture M is lower than the optimum temperature during the warm-up operation, steps ST21 and ST22 are performed as described above. , ST23, ST24, ST25, ST26, ST27, ST28 are repeated, so that the opening 91 is kept in the minimum open state P2. By maintaining the opening 91 in the minimum open state P2, as described in the first embodiment, the temperature of the exhaust G is raised, so that the warm-up operation of the internal combustion engine 20 is promoted. As a result, the temperature of the air-fuel mixture reaches the optimum temperature during the warm-up operation early. If the flag is set to 1 in step ST22 after the driving of the internal combustion engine 20 is started, the process proceeds from step ST22 to step ST25 from the next time.

  Next, an operation in a state where the warm-up operation of the internal combustion engine 20 is not completed and the temperature of the air-fuel mixture M is the optimum temperature during the warm-up operation will be described. When the temperature of the air-fuel mixture M reaches the optimum temperature during the warm-up operation after starting the internal combustion engine 20, the controller 190a does not need to increase the temperature of the air-fuel mixture M. Is determined to be unnecessary. Therefore, the process proceeds from step ST26 to step ST21. When the temperature of the air-fuel mixture M is the optimum temperature during the warm-up operation, steps ST21, ST22, ST25, ST26 are repeated. As a result, the temperature of the air-fuel mixture M further increases as the temperature of the exhaust G increases.

  Next, an operation in a state where the warm-up operation of the internal combustion engine 20 has not been completed and the temperature of the air-fuel mixture M has exceeded the optimum temperature during the warm-up operation will be described. In this state, the process proceeds from step ST27 to step ST29. In this state, the controller 190a determines that it is not necessary to increase the temperature of the catalyst device 70 because it is not necessary to increase the temperature of the mixture M. In step ST29, the control unit 190a detects the opening degree of the opening 91 by detecting the attitude of the opening / closing plate 101 based on the detection result of the rotation angle detection sensor 102a. The controller 190a determines whether or not the opening of the opening 91 is maximum, that is, whether or not the opening 91 is in the maximum open state P1.

  When the internal combustion engine 20 is not warmed up after the start of driving, and the temperature exceeds the optimum temperature for the first time during the warming up operation, the opening 91 is maintained in the minimum open state P2. Therefore, the control unit 190a determines that the opening 91 is not in the maximum open state P1. Then, the process proceeds to step ST30.

  In step ST30, the control unit 190a controls the driving device 102 to open the opening / closing number 101 in the opening direction so that the opening degree of the opening 91 is increased. Here, control of the driving device 102 for increasing the opening degree of the opening 91 will be described.

  FIG. 9 is an enlarged view showing the opening 91 and the opening / closing plate 101. As shown in FIG. 9, when the control unit 190a controls the drive device 102 to increase the opening degree of the opening 91, the opening / closing plate 101 is determined in advance in a direction in which the opening 91 approaches the maximum open state P1. A predetermined angle α is rotated. In FIG. 9, the open / close plate 101 in the minimum open state P2 is indicated by a solid line.

  Returning to the description of the operation in step ST30. The control unit 190a controls the driving device 102 and rotates the opening / closing plate 101 by a predetermined angle α in the opening direction based on the detection result of the rotation angle detection sensor 102a. When the opening / closing plate 101 is rotated by a predetermined angle α in the opening direction, the process returns to step ST21. Preferably, the predetermined angle α is set so that the rotation angle of the opening / closing plate 101 between the minimum open state P2 and the maximum open state P1 is α × K when K is a natural number equal to or greater than 1. In a case where the opening / closing plate 101 is in the maximum open state P1 after rotating the predetermined angle α a plurality of times, K is set to a plurality of times such as 4, 5 for example.

  When the warm-up operation of the internal combustion engine 20 is not completed and the temperature of the air-fuel mixture M is higher than the optimum temperature during the warm-up operation, steps ST21, ST22, ST23, ST25, ST26, ST27, ST29, and ST30 are performed. The operation is repeated. By this operation, the opening degree of the opening 91 gradually increases, so that the exhaust gas recirculation device 50a is cooled. As a result, the exhaust G guided to the intake passage 38 is cooled, so that the temperature of the air-fuel mixture M is cooled.

  If the controller 190a determines in step ST29 that the opening 91 is in the maximum open state P1, in other words, if it is determined that the opening degree of the opening 91 is maximum, the process returns from step ST29 to step ST21.

  Next, after the temperature of the air-fuel mixture M exceeds the optimum temperature during the warm-up operation before the warm-up operation of the internal combustion engine 20 is completed, the optimum during the warm-up operation is again performed as the opening of the opening 91 increases. The operation when the temperature is reached will be described. In this state, the opening degree of the opening 91 increases toward the maximum open state P1 in accordance with the number of times of passing through step ST30.

  In this state, the controller 190a determines in step ST26 that the temperature of the air-fuel mixture M is the optimum temperature during the warm-up operation, and then returns to step ST21. Thus, the opening degree at which the temperature of the air-fuel mixture M is the optimum temperature during the warm-up operation is maintained.

  Next, the warm-up operation of the internal combustion engine 20 is not completed, and the temperature of the mixture M becomes lower than the temperature during the warm-up operation after the temperature of the mixture M becomes equal to or higher than the optimum temperature during the warm-up operation. The operation in the above state will be described.

  In this state, the opening / closing plate 101 has the opening 91 at any position between the maximum opening state P1, the minimum opening state P2, or between the maximum opening state P1 and the minimum opening state P2. In this operation, the process proceeds from step ST27 to step ST28. In step ST28, the controller 190a determines whether or not the opening 91 is in the minimum open state P2, in other words, whether the opening of the opening 91 is minimum. Specifically, the control unit 190a detects the attitude of the opening / closing plate 101 based on the detection result of the rotation angle detection sensor 102a, and detects the opening degree of the opening 91. If the controller 190a determines that the opening 91 is not in the minimum open state P2, the control unit 190a then proceeds to step ST31.

  In step ST31, the control unit 190a rotates by a predetermined angle α in the closing direction of the opening / closing plate 101. As a result, the opening 91 approaches the minimum open state P2. Then, the process proceeds to step ST21.

  In a state where the temperature of the air-fuel mixture M is lower than the optimum temperature during the warm-up operation, the above steps ST21, ST22, ST23, ST24, ST25, ST26, ST27, ST28, ST31 are repeated. If the opening of the opening 91 is minimized during the repetition, in other words, when the opening 91 is in the minimum open state P2, the process returns from step ST28 to step ST21.

  Thus, when the opening degree of the opening 91 rotates in the closing direction, the temperature in the cover member 90 rises, and thus the temperature of the exhaust G is raised. As a result, the temperature of the air-fuel mixture M increases.

  In a state where the warm-up operation of the internal combustion engine 20 has not been completed, the attitude of the opening / closing plate 101 is adjusted as described above, whereby the temperature of the exhaust gas G is raised at an early stage and the temperature of the mixture M is increased. It becomes the optimum temperature during warm-up operation.

  Next, an operation after the warm-up operation of the internal combustion engine 20 is completed will be described. When determining that the temperature of the refrigerant is higher than the threshold value Twh based on the detection result of the refrigerant temperature detection sensor 180 in step ST25, the control unit 190a determines that the warm-up operation of the internal combustion engine 20 has ended, Proceed to step ST32.

  In step ST32, it is determined whether or not the temperature of the air-fuel mixture M is the optimum temperature after completion of the warm-up operation. The optimum temperature after completion of the warm-up operation is set such that the temperature of the exhaust gas G guided to the intake system 30 after the completion of the warm-up operation becomes an optimum temperature for the intake system 30. More specifically, the intake system 30 is provided with an air-fuel mixture temperature detection sensor 200, a throttle valve 31, and the like. Some of these devices and components do not have a high maximum allowable temperature. In a state where the temperature of the air-fuel mixture M is the optimum temperature after completion of the warm-up operation, the temperature of the exhaust G guided to the intake system 30 is lower than the upper limit temperature that the intake system 30 can withstand. In the present embodiment, the optimum temperature after completion of the warm-up operation is not less than the lower limit value TiLh and not more than the upper limit value TiHh (including TiLh and TiHh). The optimum temperature after completion of the warm-up operation is an example of the predetermined temperature referred to in the present invention.

  Here, the temperature Twh for determining the completion of the warm-up operation, the optimum temperature during the warm-up operation, and the optimum temperature after the completion of the warm-up operation will be described. In the first embodiment, the present embodiment, and the embodiments described after the present embodiment, the temperature Twh for determining the completion of the warm-up operation, the optimum temperature during the warm-up operation, and the optimum after the completion of the warm-up operation. The temperature is similar.

  First, the warm-up operation of the internal combustion engine 20 and the temperature for determining completion of warm-up will be described. When the internal combustion engine 20 is warmed, the temperature of the cooling water C circulating in the internal combustion engine 20 rises. Therefore, the cooling water temperature is used as an index for estimating the warming degree of the internal combustion engine 20. The cooling water temperature is controlled to about 80 to 90 ° C. (degrees Celsius) by a radiator or thermostat (not shown).

  The water temperature at the start of the internal combustion engine 20 is substantially the atmospheric temperature. Although atmospheric temperature changes with areas, it is -35 degreeC-50 degreeC. Immediately after the internal combustion engine 20 is started, the combustion stability is poor, and the amount of unburned components HC and CO is large, so the exhaust becomes worse. Further, since the internal combustion engine 20 is cold, clearances of sliding portions such as between the piston and cylinder, between the crank bearing and the crankshaft, and between the cam bearing and the camshaft are narrow. For this reason, there is a lot of friction, and the fuel consumption deteriorates.

  In order to improve these problems at an early stage, warming up of the internal combustion engine 20 is promoted. The cooling water temperature is approximately 65 ° C. when the water temperature rises after the internal combustion engine 20 is started and the above-mentioned problems in the cold state are solved. In the present embodiment, the temperature Twh, which is the cooling water temperature when the warm-up of the internal combustion engine 20 is completed, is 65 ° C. (degrees Centigrade) as an example. Note that the temperature at which completion of warm-up operation is determined may vary depending on the vehicle type.

  Next, the optimum temperature during warm-up operation and the optimum temperature after completion of warm-up operation will be described. The optimum temperature during warm-up operation is not less than TiLc and not more than TiHc. The optimum temperature after completion of the warm-up operation is not less than TiLh and not more than TiHh.

  During the warm-up operation of the internal combustion engine 20, unburned components HC and CO are often discharged due to the reason that combustion stability is low, combustion temperature is low, and misfire and partial flame extinction easily occur. For this reason, in order to promote warm air promotion by introducing the warm air-fuel mixture M into the cylinder and reduce the discharge amount of the unburned components HC and CO, the optimum temperature of the air-fuel mixture M is set higher. As a result, the amount of fuel is not increased to promote warm-up operation of the internal combustion engine 20, or the amount to be increased can be reduced even when the amount of fuel is increased.

  On the other hand, after the warm-up operation of the internal combustion engine 20 is completed, if the combustion temperature is high, the NOx emission amount increases, so the temperature of the air-fuel mixture sucked into the cylinder is lowered, and NOx is reduced. NOx increases with an exponential function of combustion temperature. For this reason, the amount of generation increases explosively at temperatures from around 1200 ° C. and beyond.

  For this reason, in the present embodiment, the optimum temperature during warm-up operation is set higher than the optimum temperature after completion of warm-up operation. In this embodiment, TiLc is 50 ° C. and TiHc is 70 ° C. In this embodiment, TiLh is 25 ° C. and TiHh is 45 ° C.

  Returning to the description of the operation of the exhaust gas recirculation device 50. Here, first, an operation in a state where the temperature of the air-fuel mixture M is lower than the optimum temperature after completion of the warm-up operation will be described. In this case, the process proceeds from step ST32 to step ST34 via step ST33. Since the temperature of the air-fuel mixture M is lower than the lower limit value TiLh, the control unit 190a determines that the temperature of the catalyst device 70 needs to be increased in order to increase the temperature of the exhaust gas G. The mixture temperature detection sensor 200 is an example of a temperature rise determination means referred to in the present invention.

  In step ST34, the control unit 190a determines whether or not the opening 91 is in the minimum open state P2. Specifically, the control unit 190a detects the attitude of the opening / closing plate 101 based on the detection result of the rotation angle detection sensor 102a, and detects the opening degree of the opening 91. If the control part 190a determines with the opening 91 being the minimum open state P2, it will return to step ST21. If it is determined that the opening degree of the opening 91 is not the minimum, that is, the minimum opening state P2, the process proceeds to step ST35.

  In step ST <b> 35, the control unit 190 a rotates the opening / closing plate 101 by a predetermined angle α in the closing direction in order to reduce the opening degree of the opening 91. Then, the process returns to step ST21.

  After the warm-up operation is completed, if the temperature of the exhaust G is lower than the optimum temperature after the warm-up operation is completed, the opening of the opening 91 is reduced by repeating the operations of steps ST25, ST32, ST34, and ST35. The temperature in 90 rises. As a result, the temperature of the air-fuel mixture M increases as the temperature of the exhaust G increases.

  Next, the operation in a state where the temperature of the air-fuel mixture M has reached the optimum temperature after the completion of the warm-up operation after the completion of the warm-up operation of the internal combustion engine 20 will be described. If the controller 190a determines in step ST32 that the temperature of the mixture M is the optimum temperature after completion of the warm-up operation based on the detection result of the mixture temperature detection sensor 200, the temperature increase of the mixture M is not required. Therefore, it is determined that it is not necessary to raise the temperature of the catalyst device 70. Then, the process returns to step ST21. As described above, after the warm-up operation is completed, when it is determined that the temperature of the air-fuel mixture M is the optimum temperature after the warm-up operation is completed, the opening degree of the opening 91 is maintained as it is. In other words, the posture of the opening / closing plate 101 is maintained.

  Next, the operation in a state in which the temperature of the air-fuel mixture M exceeds the optimum temperature after completion of the warm-up operation after completion of the warm-up operation of the internal combustion engine 20 will be described. When determining that the detected temperature of the mixture M has exceeded the optimum temperature after completion of the warm-up operation based on the detection result of the mixture temperature detection sensor 200, the control unit 190a proceeds from step ST33 to step ST36. Since the temperature of the air-fuel mixture M is higher than the upper limit value TiHh, the controller 190a determines that the temperature of the air-fuel mixture M does not need to be increased, and therefore the temperature of the catalyst device 70 does not need to be increased.

  In step ST36, the control unit 190a determines whether or not the opening 91 is in the maximum open state P1, based on the detection result of the rotation angle detection sensor 102a, in other words, whether or not the opening of the opening 91 is maximum. . If the control part 190a determines with the opening degree of the opening 91 being the maximum, it will return to step ST21 then. Moreover, when the opening degree of the opening 91 is not the maximum in step ST36, it progresses to step ST37. In step ST37, the control unit 190a controls the driving device 102 based on the detection result of the rotation angle detection sensor 102a to rotate the opening / closing plate 101 by a predetermined angle α in the opening direction.

  When the temperature of the air-fuel mixture M is higher than the optimum temperature after completion of the warm-up operation, the exhaust G supplied to the intake passage 38 is adjusted by adjusting the posture of the opening / closing plate 101 so that the opening degree of the opening 91 is increased. Since it is cooled, the temperature of the air-fuel mixture M decreases. After the warm-up operation of the internal combustion engine 20 is completed, the attitude of the opening / closing plate 101 is adjusted as described above, so that the temperature of the air-fuel mixture M is maintained at the optimum temperature after the warm-up operation is completed.

  If the driving of the internal combustion engine 20 is stopped during the operation according to the flowchart shown in FIG. 8, the process proceeds from step ST21 to step S8. In step ST38, the control unit 190a sets a flag to 0. Next, the operation is completed.

  In the present embodiment, the same effect as in the first embodiment can be obtained. Further, in the present embodiment, before and after the warm-up operation is completed, the posture of the opening / closing plate 101 is adjusted, and the temperature of the mixture M is set to the optimum temperature during the warm-up operation or the optimum temperature after the completion of the warm-up operation. maintain. For this reason, it is suppressed that a malfunction occurs in the intake system 30 due to the temperature of the exhaust G that is guided.

  Next, an exhaust gas recirculation apparatus according to a third embodiment of the present invention will be described with reference to FIG. In addition, the structure which has the same function as 1st Embodiment attaches | subjects the code | symbol same as 1st Embodiment, and abbreviate | omits description. In this embodiment, the point provided with the cooler 130 for exhaust gas recirculation apparatuses differs from 1st Embodiment. Other structures are the same as those in the first embodiment. The different points will be specifically described.

  In addition, the code | symbol 50b is attached | subjected to the exhaust gas recirculation apparatus of this embodiment. As described above, the exhaust gas recirculation device 50b differs from the exhaust gas recirculation device 50 described in the first embodiment only in that the exhaust gas recirculation device cooler 130 is provided. The other structure is the same as that of the exhaust gas recirculation device 50.

  FIG. 10 is a plan view showing the exhaust gas recirculation device 50b. As shown in FIG. The exhaust gas recirculation device 50b further includes an exhaust gas recirculation device cooler 130 in addition to the exhaust gas recirculation device 50 described in the first embodiment.

  The exhaust gas recirculation device cooler 130 is incorporated in the second connection passage portion 82, downstream of the downstream side bellows tube member 81, and upstream of the junction between the exhaust gas recirculation passage 120 and the intake passage 38. It is arranged at the position. The exhaust G flows in the cooler 130 for the exhaust gas recirculation device. The exhaust gas recirculation device cooler 130 is disposed outside the cover member 90. The exhaust gas recirculation device cooler 130 cools the exhaust gas G flowing in the exhaust gas recirculation device cooler 130. The cooler 130 for the exhaust gas recirculation device is an example of the cooling device referred to in the present invention.

  The exhaust gas recirculation device cooler 130 cools the exhaust gas G flowing inside by using a common refrigerant for cooling the internal combustion engine 20. In the present embodiment, the cooling water C is used as the refrigerant. The cooling water C circulates in the exhaust gas recirculation device cooler 130 and the internal combustion engine 20, and cools the exhaust gas G flowing in the exhaust gas recirculation device cooler 130 and the internal combustion engine 20.

  In the present embodiment, the same effect as in the first embodiment can be obtained. Further, in the cold state, the exhaust gas G that has been efficiently heated by the cover member 90 flows through the exhaust gas recirculation device cooler 130. For this reason, since the temperature of the cooling water C flowing through the exhaust gas recirculation device cooler 130 is increased by the exhaust G, the warm-up operation of the internal combustion engine 20 can be promoted.

  Further, when the internal combustion engine 20 is in a warm state, the exhaust gas G, which has been heated by the catalytic reaction when passing through the catalyst 72, is cooled by the exhaust gas recirculation device cooler 130, whereby a large amount of the exhaust gas G is combusted. Can be supplied to.

  Note that the exhaust gas recirculation device 50a described in the second embodiment may include the exhaust gas recirculation device cooler 130 as in the present embodiment. In this case, in addition to the effects of the second embodiment, the effects of the above-described exhaust gas recirculation device cooler 130 can be obtained.

  Next, an exhaust gas recirculation apparatus according to a fourth embodiment of the present invention will be described with reference to FIGS. In addition, the structure which has the same function as 1st Embodiment attaches | subjects the code | symbol same as 1st Embodiment, and abbreviate | omits description.

  In this embodiment, the point provided with the exhaust gas recirculation device cooler 130, the exhaust gas recirculation device cooler bypass passage 140, and the flow path switching valve device 150, and the point provided with a control unit 190c instead of the control unit 190, Different from the first embodiment. Other structures are the same as those in the first embodiment. The different points will be specifically described.

  For this reason, the reference numeral 50c is given to the exhaust gas recirculation device of the present embodiment. As described above, the exhaust gas recirculation device 50c is different from the exhaust gas recirculation device 50 described in the first embodiment in that the exhaust gas recirculation device cooler 130, the exhaust gas recirculation device cooler bypass passage 140, and the flow path switching valve. Only the point provided with the device 150 and the point provided with the control unit 190c instead of the control unit 190 are different. Other structures are the same as those of the exhaust gas recirculation apparatus 50 of the first embodiment.

  In the present embodiment, instead of the control means 170, the controller 190c, the switching device 100, the refrigerant temperature detection sensor 180, the exhaust gas recirculation device cooler 130, the exhaust gas recirculation device cooler bypass passage 140, and the flow path switching. The valve device 150 constitutes the control means 170c.

  FIG. 11 is a schematic view showing the exhaust gas recirculation device 50c. As shown in FIG. 11, the exhaust recirculation device cooler 130 is incorporated in the second connecting passage portion 82, is downstream of the downstream side bellows tube member 81, and is connected to the exhaust recirculation passage 120 and the intake passage. 38 is arranged at a position upstream of the junction with 38. The exhaust G flows in the cooler 130 for the exhaust gas recirculation device. The exhaust gas recirculation device cooler 130 is disposed outside the cover member 90. The exhaust gas recirculation device cooler 130 cools the exhaust gas G passing through the exhaust gas recirculation device cooler 130. The cooler 130 for the exhaust gas recirculation device is an example of the cooling device referred to in the present invention.

  The exhaust gas recirculation device cooler 130 cools the exhaust gas G flowing inside by using a common refrigerant for cooling the internal combustion engine 20. In the present embodiment, the cooling water C is used as the refrigerant. The cooling water C circulates in the exhaust gas recirculation device cooler 130 and the internal combustion engine 20, and cools the exhaust gas G flowing in the exhaust gas recirculation device cooler 130 and the internal combustion engine 20.

  The cooler bypass passage 140 for the exhaust gas recirculation device constitutes a part of the downstream exhaust gas recirculation passage 80. The exhaust gas recirculation device cooler bypass passage 140 bypasses the exhaust gas recirculation device cooler 130. Specifically, the upstream end of the exhaust gas recirculation device cooler bypass passage 140 communicates upstream of the exhaust gas recirculation device cooler 130 in the second connection passage portion 82. The downstream end of the exhaust gas recirculation device cooler bypass passage 140 communicates downstream of the exhaust gas recirculation device cooler 130 in the second connection passage portion 82. The cooler bypass passage 140 for the exhaust gas recirculation device is an example of a bypass passage in the present invention.

  The flow path switching valve device 150 includes a drive device 151, a first valve 152, a second valve 153, and a rotation angle detection sensor 157.

  The first valve 152 is a butterfly valve, and includes a valve body 154 and a rotating shaft 155. The valve body 154 is provided integrally with the rotary shaft 155 and rotates in accordance with the rotation of the rotary shaft 155. The valve body 154 is disposed in the cooler bypass passage 140 for the exhaust gas recirculation device.

  The rotation of the rotating shaft 155 causes the valve body 154 to rotate in the exhaust gas recirculation device cooler bypass passage 140, and thus the posture of the valve body 154 changes. As a result, the first valve 152 is opened and closed. When the first valve 152 is opened and closed, the exhaust gas recirculation device cooler bypass passage 140 is opened and closed, and the opening degree of the exhaust gas recirculation device cooler bypass passage 140 can be adjusted.

  Opening the first valve 152 means adjusting the posture of the valve main body 154 so that the exhaust G passes through the cooler bypass passage 140 for the exhaust gas recirculation device. The state in which the first valve 152 is opened to the maximum is a state in which the opening degree is maximized by adjusting the posture of the valve body 154. When the first valve 152 is fully closed, the opening is minimized and the exhaust G does not pass through the cooler bypass passage 140 for the exhaust gas recirculation device. That is, the flow rate of the exhaust gas G flowing through the exhaust gas recirculation device cooler bypass passage 140 is 0 (zero).

  The second valve 153 is a butterfly valve, and includes a valve body 156 and a rotating shaft 155. The rotating shaft 155 is used in common by the first and second valves 152 and 153. The valve body 156 is provided integrally with the rotation shaft 155 and rotates in accordance with the rotation of the rotation shaft 155.

  The valve body 156 is disposed in the downstream side exhaust gas recirculation passage 80 at a position downstream of the exhaust gas recirculation device cooler 130 and upstream of the junction 160 with the exhaust gas recirculation device cooler bypass passage 140. The rotation of the rotary shaft 155 causes the valve body 156 to rotate in the downstream exhaust gas recirculation passage 80, and thus the posture of the valve body 156 changes. As a result, the second valve 153 is opened and closed. By opening and closing the second valve 153, the downstream side exhaust gas recirculation passage 80 can be opened and closed, and the opening degree of the downstream side exhaust gas recirculation passage 80 can be adjusted.

  To open the second valve 153 is to adjust the posture of the valve body 156 so that the exhaust G passes through the exhaust recirculation cooler 130. The fully opened state of the second valve 153 is a state where the opening degree of the second valve 153 is maximized. The fully closed state of the second valve 153 is a state in which the opening is minimized and the exhaust G does not pass through the exhaust recirculation cooler 130.

  Here, the posture of the valve bodies 154 and 156 on the rotating shaft 155 will be described. The first and second valves 152 and 153 are provided such that when one of them is fully closed and the passage is closed to stop the flow of the exhaust G, the other is fully open and the passage is opened and the exhaust G is allowed to flow. . Specifically, as shown in FIG. 11, when the valve main body 154 is in a fully closed posture in which the exhaust gas recirculation device cooler bypass passage 140 is closed, the valve main body 156 is in a posture to open the downstream side exhaust gas recirculation passage 80 to the maximum. . In this state, all the exhaust gas G that has passed through the catalyst device 70 passes through the cooler 130 for the exhaust gas recirculation device. This state is the second state in the present invention.

  Similarly, when the rotary shaft 155 is rotated and the valve main body 156 is in a fully closed posture in which the downstream exhaust gas recirculation passage 80 is blocked, the valve main body 154 is in a posture to open the exhaust gas recirculation device cooler bypass passage 140 to the maximum. . In this state, all the exhaust gas G that has passed through the catalyst device 70 bypasses the exhaust gas recirculation device cooler 130 and passes through the exhaust gas recirculation device cooler bypass passage 140.

  The driving device 151 rotates the rotation shaft 155. The rotation angle detection sensor 157 detects the rotation angle of the rotation shaft 155.

  The control unit 190c is connected to the refrigerant temperature detection sensor 180, the drive device 102, the rotation angle detection sensor 102a, the drive device 151, and the rotation angle detection sensor 157.

  The control unit 190c transmits the detection result of the refrigerant temperature detection sensor 180. Based on the detection result of the refrigerant temperature detection sensor 180, the controller 190c detects the temperature of the cooling water C and determines whether the warm-up operation of the internal combustion engine 20 has been completed.

  The controller 190c and the refrigerant temperature detection sensor 180 determine whether or not the temperature of the catalyst device 70 needs to be increased based on the temperature of the cooling water C. The control unit 190c and the refrigerant temperature detection sensor 180 constitute an example of a temperature rise determination unit referred to in the present invention.

  The control unit 190c controls the driving device 102 to rotate the opening / closing plate 101. The control unit 190c transmits the detection angle of the rotation angle detection sensor 102a. The control unit 190c detects the attitude of the opening / closing plate 101 based on the result of the rotation angle detection sensor 102a. Thus, the control unit 190c can obtain the opening degree of the opening 91. More specifically, the control unit 190c can obtain whether the opening 91 is in the maximum open state P1 or the minimum open state P2. The opening degree of the opening 91 changes depending on the posture of the opening / closing plate 101. The opening degree of the opening 91 is determined in advance according to the posture of the opening / closing plate 101 and stored in the control unit 10c. The control unit 190c can determine the opening degree of the opening 91 from the posture of the opening / closing plate 101. The control unit 190 detects the start of operation and the completion of operation of the internal combustion engine 20.

  The control unit 190c controls the driving device 151 to rotate the rotating shaft 155. The control unit 190c transmits the detection result of the rotation angle detection sensor 157. The control unit 190c detects the postures of the valve bodies 154 and 156 based on the detection result of the rotation angle detection sensor 157. By detecting the postures of the valve bodies 154 and 156, the opening degrees of the first and second valves 152 and 153, in other words, the opening degrees of the exhaust gas recirculation device cooler bypass passage 140 and the downstream exhaust gas recirculation passage 80 are detected. And detect.

  Next, the operation of the exhaust gas recirculation device 50c will be described. FIG. 12 is a flowchart showing the operation of the exhaust gas recirculation device 50c. First, the operation until the warm-up operation of the internal combustion engine 20 is completed will be described. As shown in FIG. 12, the controller 190c determines whether or not the internal combustion engine 20 has started driving in step ST41. In this state, since the internal combustion engine 20 is driven, the process proceeds to step ST42.

  In step ST42, the control unit 190c determines whether or not the flag is set to 1. Immediately after driving of the internal combustion engine 20 is started, the flag remains 0 and is not set to 1. Therefore, the control unit 190c determines that the flag is not 1. Then, the process proceeds to step ST43. In step ST43, the control unit 190c sets a flag to 1. Then, the process proceeds to step ST44.

  In step ST44, the control unit 190c controls the driving device 102 and maximizes the opening degree of the opening 91 based on the detection result of the rotation angle detection sensor 102a. In other words, the opening 91 is set to the maximum open state P1. Then, the control unit 190c controls the driving device 151, opens the first valve 152 to the maximum based on the detection result of the rotation angle detection sensor 157, and fully closes the second valve 153. Thus, the exhaust gas G passes through the exhaust gas recirculation device cooler bypass passage 140 without passing through the exhaust gas recirculation device cooler 130. This state is described as cooler bypass ON in step ST44 of FIG. Then, the process proceeds to step ST45.

  In step ST45, the control unit 190c determines whether or not the warm-up operation of the internal combustion engine 20 has been completed. Specifically, control unit 190c determines whether or not cooling water C is greater than threshold value Twh based on the detection result of refrigerant temperature detection sensor 180. In this description, since the warm-up operation is not completed, the control unit 190c determines that the temperature of the cooling water C is equal to or lower than the threshold value Twh. Then, the process proceeds to step ST46.

  If the temperature of the cooling water C is equal to or lower than the threshold value Twh, it is necessary to raise the temperature of the internal combustion engine 20, and therefore the controller 190c determines that the temperature of the catalyst device 70 needs to be raised in order to raise the temperature of the exhaust G. . In step ST46, the control unit 190c controls the driving device 102 and sets the opening of the opening 91 to the minimum, that is, sets the opening 91 to the minimum open state P2 based on the detection result of the rotation angle detection sensor 102a. Then, the control unit 190c controls the driving device 151, and based on the detection result of the rotation angle detection sensor 157, the first valve 152 is fully opened and the second valve 153 is fully closed. As a result, the exhaust G passes through the exhaust gas recirculation device cooler bypass passage 140 without passing through the exhaust gas recirculation device cooler 130. In step ST46 of FIG. 12, the state of the first and second valves 152 and 153 is represented as cooler bypass ON. Then, the process returns to step ST41.

  Until the warm-up operation of the internal combustion engine 20 is completed, steps ST41, ST42, ST43, ST44, ST45, and ST46 are repeated. Note that after the flag is set to 1, the process proceeds from step ST42 to step ST45. By repeating steps ST41, ST42, ST43, ST44, ST45, and ST45, the opening of the opening 91 is minimized and the cooler bypass ON state is maintained. When the opening 91 is minimized, the temperature of the exhaust G is raised quickly. Furthermore, since the cooler bypass is turned OFF, the exhaust G does not pass around the exhaust recirculation device cooler 130, so that the exhaust G is not cooled by the exhaust recirculation device cooler 130. From the above, the warm-up operation of the internal combustion engine 20 is promoted.

  Next, an operation after the warm-up operation of the internal combustion engine 20 is completed will be described. When determining that the temperature of the cooling water C has exceeded the threshold value Twh based on the detection result of the refrigerant temperature detection sensor 180 in step ST45, the control unit 190c proceeds to step ST47.

  If the temperature of the cooling water C is higher than the threshold value Twh, it is not necessary to raise the temperature of the internal combustion engine 20, and therefore the controller 190c determines that the temperature of the catalyst device 70 is not required to be raised. In step ST47, the control unit 190c controls the drive device 102 and maximizes the opening of the opening 91 based on the detection result of the rotation angle detection sensor 102a. Then, the control unit 190c controls the driving device 151, and based on the detection result of the rotation angle detection sensor 157, the first valve 152 is fully closed and the second valve 153 is fully opened. Thus, the exhaust gas G passes through the exhaust gas recirculation device cooler 130 without passing through the exhaust gas recirculation device cooler bypass passage 140. In step ST47 of FIG. 12, the state of the first and second valves 152 and 153 is represented as cooler bypass OFF.

  After the warm-up operation is completed, the operations of steps ST41, ST42, ST43, ST44, ST45, ST47 are repeated. The exhaust G is cooled when the opening 91 is maximized. Further, the exhaust gas G is cooled by passing through the exhaust gas recirculation device cooler 130.

  If the control part 190c determines with the drive of the internal combustion engine 20 being stopped by step ST41, it will progress to step ST48. In step ST48, the control unit 190c sets a flag to 0. Next, the operation of the exhaust gas recirculation device 50c ends.

  In the present embodiment, the same effect as in the first embodiment can be obtained. Further, by providing the exhaust gas recirculation device cooler bypass passage 140, the exhaust gas recirculation device cooler 130 can be bypassed when the internal combustion engine 20 is in a cold state such as when the warm-up operation is not completed. A high-temperature mixture M can be supplied. As a result, the generation of NOx can be suppressed.

  Next, an exhaust gas recirculation apparatus according to a fifth embodiment of the present invention will be described with reference to FIGS. In addition, the structure which has a function similar to 4th Embodiment attaches | subjects the same code | symbol as 4th Embodiment, and abbreviate | omits description. The exhaust gas recirculation apparatus of the present embodiment is only provided with an air-fuel mixture temperature detection sensor 200 for detecting the temperature of the air-fuel mixture M, and only provided with a control unit 190d instead of the control unit 190c. Different from the device 50c. The other structure is the same as that of the exhaust gas recirculation device 50c. For this reason, reference numeral 50d is given to the exhaust gas recirculation device of the present embodiment. Only the different points will be described specifically.

  FIG. 13 is a plan view showing the exhaust gas recirculation device 50d. As shown in FIG. 13 and as described above, the exhaust gas recirculation device 50d has the fourth feature only in that it includes the mixture temperature detection sensor 200 and a point provided with a control unit 190d instead of the control unit 190c. Different from the exhaust gas recirculation device 50c of the embodiment.

  In the present embodiment, instead of the control means 170c, the control unit 190d, the refrigerant temperature detection sensor 180, the switching device 100, the mixture temperature detection sensor 200, the exhaust gas recirculation device cooler 130, and the exhaust gas recirculation device cooler. The bypass passage 140 and the flow path switching valve device 150 constitute a control means 170d.

  The mixture temperature detection sensor 200 detects the temperature of the mixture M of air and exhaust G supplied to the combustion chambers 21 to 24. The mixture temperature detection sensor 200 is provided in the intake manifold 32.

  The control unit 190d is connected to the refrigerant temperature detection sensor 180, the drive device 102, the rotation angle detection sensor 102a, the drive device 151, the rotation angle detection sensor 157, and the mixture temperature detection sensor 200.

  The detection result of the refrigerant temperature detection sensor 180 is transmitted to the control unit 190d. Based on the detection result of the refrigerant temperature detection sensor 180, the control unit 190 detects the temperature of the cooling water C and determines whether the warm-up operation of the internal combustion engine 20 has been completed.

  The controller 190d and the refrigerant temperature detection sensor 180 determine whether or not the temperature of the catalyst device 70 needs to be increased based on the temperature of the cooling water C. The control unit 190d and the refrigerant temperature detection sensor 180 constitute an example of a temperature rise determination unit referred to in the present invention.

  The control unit 190d controls the driving device 102 to rotate the opening / closing plate 101. The control unit 190d transmits the detection angle of the rotation angle detection sensor 102a. The control unit 190d detects the attitude of the opening / closing plate 101 based on the result of the rotation angle detection sensor 102a. Thus, the control unit 190d can obtain the opening degree of the opening 91. More specifically, the control unit 190d can obtain whether the opening 91 is in the maximum open state P1 or the minimum open state P2. The opening degree of the opening 91 is determined in advance according to the posture of the opening / closing plate 101 and is stored in the control unit 190d. The control unit 190d can obtain the opening degree of the opening 91 from the posture of the opening / closing plate 101. Further, the control unit 190d detects the start and end of the operation of the internal combustion engine 20.

  The control unit 190d controls the driving device 151 to rotate the rotation shaft 155. The control unit 190d transmits the detection result of the rotation angle detection sensor 157. The control unit 190d detects the postures of the valve bodies 154 and 156 based on the detection result of the rotation angle detection sensor 157. The opening degrees of the first and second valves 152 and 153 are determined in advance according to the attitude of the rotating shaft 155 and stored in the control unit 190d. The control unit 190d detects the positions of the valve bodies 154 and 156, thereby opening the first and second valves 152 and 153, in other words, the opening of the exhaust gas recirculation device cooler bypass passage 140 and the downstream exhaust gas recirculation. The opening with the passage 80 is detected.

  Further, by detecting the opening degree of the first and second valves 152 and 153, the flow rate of the exhaust gas G flowing through the exhaust gas recirculation device cooler 130 and the flow rate of the exhaust gas G flowing through the exhaust gas recirculation device cooler bypass passage 140 are calculated. The ratio of the flow rate of the exhaust gas G flowing through the exhaust gas recirculation device cooler bypass passage 140 with respect to the total is detected. The ratio of the flow rate of the exhaust gas G flowing through the exhaust gas recirculation device cooler bypass passage 140 is determined in advance according to the opening degree of the first and second valves 152 and 153 and stored in the control unit 190d. The control unit 190d can determine the ratio of the flow rate of the exhaust gas G flowing through the exhaust gas recirculation device cooler bypass passage 140 based on the opening degree of the first and second valves 152 and 153.

  In this way, the control unit 190d can control the flow rate of the exhaust gas G flowing through the exhaust gas recirculation device cooler bypass passage 140 by controlling the rotation of the rotating shaft 155.

  The control unit 190d transmits the detection result of the mixture temperature detection sensor 200. The control unit 190d detects the temperature of the air-fuel mixture M in the intake manifold 32 based on the detection result of the air-fuel mixture temperature detection sensor 200.

  Next, the operation of the exhaust gas recirculation device 50d will be described. FIG. 14 is a flowchart showing the operation of the exhaust gas recirculation device 50d.

  First, the operation after the start of driving of the internal combustion engine 20 until the warm-up operation is completed will be described. As shown in FIG. 14, if the control part 190d determines with the internal combustion engine 20 having been driven by step ST51, it will progress to step ST52.

  In step ST52, the control unit 190d determines whether or not the flag is set to 1. Immediately after the start of driving of the internal combustion engine 20, the flag is set to 0 and not 1. For this reason, the controller 190d determines that the flag is not set to 1, and then proceeds to step ST53. In step ST53, the control unit 190d sets a flag to 1. Then, the process proceeds to step ST54.

  In step ST54, the control unit 190d controls the drive device 102 and minimizes the opening degree of the opening 91 based on the detection result of the rotation angle detection sensor 102a. In other words, the opening 91 is set to the minimum open state P2. Then, the control unit 190d controls the driving device 151, and based on the detection result of the rotation angle detection sensor 157, the first valve 152 is fully opened and the second valve 153 is fully closed. Thus, the exhaust gas G passes through the exhaust gas recirculation device cooler bypass passage 140 without passing through the exhaust gas recirculation device cooler 130. In step ST54 in FIG. 14, the state in which the exhaust gas recirculation device cooler bypass passage 140 is open and the downstream exhaust gas recirculation passage 80 is closed is represented as a bypass rate of 100%. The bypass rate is the ratio of the flow rate of the exhaust gas G passing through the first valve 152 to the total value of the flow rate of the exhaust gas G passing through the first valve 152 and the flow rate of the exhaust gas G passing through the second valve 153. It is expressed as a percentage. When the first valve 152 is fully open and the second valve 153 is fully closed, the bypass rate is 100%. When the first valve 152 is fully closed and the second valve 153 is fully open, the bypass rate is 0%. The bypass rate is determined in advance according to the attitude of the rotating shaft 155 and is stored in the control unit 190d. The control unit 190d can obtain the bypass rate based on the attitude of the rotating shaft 155. Then, the process proceeds to step ST55.

  In step ST55, the control unit 190d determines whether or not the temperature of the cooling water C is higher than the threshold value Twh based on the detection result of the refrigerant temperature detection sensor 180. Since this state is a state where the warm-up operation of the internal combustion engine 20 is not completed, the control unit 190d determines that the temperature of the cooling water C is equal to or lower than the threshold value Twh. Then, the process proceeds to step ST56.

  When the temperature of the cooling water C is equal to or lower than the threshold value Twh, it is necessary to raise the temperature of the internal combustion engine 20, and therefore the control unit 190d determines that the temperature of the catalyst device 70 needs to be raised in order to raise the temperature of the exhaust G. . In step ST56, the control unit 190d controls the drive device 102 and sets the opening of the opening 91 to the minimum, in other words, sets the opening 91 to the minimum open state P2 based on the detection result of the rotation angle detection sensor 102a. Then, the control unit 190d controls the driving device 151 and, based on the detection result of the rotation angle detection sensor 157, fully opens the first valve 152 and sets the second valve 135 to make the bypass rate 100%. Fully closed. Then, the process returns to step ST51.

  Until the warm-up operation of the internal combustion engine 20 is completed, steps ST51, ST52, ST53, ST54, ST55, ST56 are repeated. As a result, the opening degree of the opening 91 is minimized, so that the temperature of the exhaust gas G is raised quickly, the catalyst device 70 is activated early, and the exhaust gas G bypasses the cooler 130 for the exhaust gas recirculation device. Is supplied to the combustion chambers 21 to 24 to suppress the generation of NOx. After the flag is set to 1, the process proceeds from step ST52 to step ST55.

  Next, after the warm-up operation of the internal combustion engine 20 is completed, an operation in a state where the temperature of the air-fuel mixture M is lower than the optimum temperature after the warm-up operation is completed will be described. In this state, the opening degree of the opening 91 is the minimum, and the bypass rate is 100%. The optimum temperature after completion of the warm-up operation referred to here is the same as that described in the second embodiment, and is an example of the predetermined temperature referred to in the present invention.

  When determining that the temperature of the cooling water C is higher than the threshold value Twh based on the detection result of the refrigerant temperature detection sensor 180 in step ST55, the control unit 190d determines that the warm-up operation of the internal combustion engine 20 is completed, and then Proceed to step ST57.

  In step ST57, the control unit 190d determines whether or not the temperature of the air-fuel mixture M is the optimum temperature after completion of the warm-up operation based on the detection result of the air-fuel mixture temperature detection sensor 200. In this description, since the temperature of the air-fuel mixture M is lower than the optimum temperature after completion of the warm-up operation, the control unit 190d determines that the air-fuel mixture M is lower than the optimum temperature after completion of the warm-up operation, and then goes through step ST58. Proceed to step ST59.

  Since the temperature of the air-fuel mixture M is lower than the lower limit value TiLh, the control unit 190d determines that the temperature of the catalyst device 70 needs to be raised in order to raise the temperature of the exhaust G. In step ST59, the control unit 190d determines whether or not the opening degree of the opening 91 is minimum based on the detection result of the rotation angle detection sensor 102a. Immediately after the warm-up operation is completed, since the opening degree of the opening 91 is the minimum, the process proceeds to step ST60. The mixture temperature detection sensor 200 is an example of a temperature rise determination means referred to in the present invention.

  In step ST60, the control unit 190d determines whether or not the bypass rate is 100% based on the detection result of the rotation angle detection sensor 157. Specifically, the control unit 190d determines whether or not the first valve 152 is fully opened and the second valve 153 is fully closed.

  Immediately after the warm-up operation is completed, since the opening degree of the first valve 152 is in the maximum state and the opening degree of the second valve 153 is in the minimum state, the process returns to step ST51. After the warm-up operation is completed, the operations of steps ST51, ST52, ST55, ST57, ST58, ST59, and ST60 are repeated until the temperature of the air-fuel mixture M reaches the optimum temperature after completion of the warm-up operation. As a result, the opening of the opening 91 is kept to a minimum, the first valve 152 is fully opened, and the second valve 153 is fully closed, so that the temperature of the exhaust G increases, Therefore, the temperature of the air-fuel mixture M increases.

  Next, the operation in a state where the temperature of the air-fuel mixture M has reached the optimum temperature after the completion of the warm-up operation after the completion of the warm-up operation of the internal combustion engine 20 will be described. In step ST57, the control unit 190d determines whether or not the temperature of the air-fuel mixture M is the optimum temperature after completion of the warm-up operation based on the detection result of the air-fuel mixture temperature detection sensor 200. In this description, since the temperature of the air-fuel mixture M is the optimum temperature after completion of the warm-up operation, the control unit 190d determines that it is not necessary to raise the temperature of the catalyst device 70. Then, the process returns to step ST51.

  After the warm-up operation of the internal combustion engine 20 is completed, when the temperature of the air-fuel mixture M is the optimum temperature after the warm-up operation is completed, steps ST51, ST52, ST55, and ST57 are repeated. As a result, the opening degree of the opening 91 and the bypass rate are maintained, so that the temperature of the air-fuel mixture M is maintained at the optimum temperature after the warm-up operation is completed.

  Next, the operation in the state where the temperature of the air-fuel mixture M exceeds the optimum temperature after completion of the warm-up operation after completion of the warm-up operation of the internal combustion engine 20 will be described. In this state, the opening degree of the opening 91 is minimum and the bypass rate is 100%.

  If the controller 190d determines in step ST58 that the temperature of the mixture M has become higher than the optimum temperature after completion of the warm-up operation based on the detection result of the mixture temperature detection sensor 200, the control unit 190d then proceeds to step ST61.

  Since the temperature of the air-fuel mixture M is higher than the upper limit value TiHh, it is not necessary to raise the temperature of the exhaust G. Therefore, the control unit 190d determines that it is not necessary to raise the temperature of the catalyst device 70. In step ST61, the control unit 190d determines whether or not the bypass rate is zero. Specifically, the control unit 190d detects the bypass rate based on the detection result of the rotation angle detection sensor 157. In this state, since the bypass rate is 100%, the process proceeds to step ST62.

  In step ST62, the control unit 190d controls the drive device 102 and maintains the opening of the opening 91 based on the detection result of the rotation angle detection sensor 102a. Then, the control unit 190d decreases the opening degree of the first valve 152 and increases the opening degree of the second valve 153 so that the bypass rate decreases.

  Specifically, the control unit 190d controls the driving device 151 to rotate the rotating shaft 155 in the direction in which the first valve 152 is closed and the second valve 153 is opened. At this time, the rotation shaft 155 is rotated by a predetermined angle β. The predetermined angle β is a value determined in advance. Preferably, when the predetermined angle β is a natural number equal to or greater than L = 1, the rotation of the rotary shaft 155 between the maximum opening (fully opened state) and the minimum opening (fully closed state) of the first valve 152 is performed. The angle is a value at which L × β. In the case where the minimum opening degree is changed to the maximum opening degree after the operation of rotating the rotation shaft 155 by a predetermined angle β is performed a plurality of times, L is set to a plurality of times such as 4, 5 times. When the rotation shaft 155 is rotated by a predetermined angle β in the direction in which the first valve 152 is opened and the second valve 153 is closed, the process returns to step ST51.

  After the warm-up operation of the internal combustion engine 20 is completed, in a state where the temperature of the air-fuel mixture M exceeds the optimum temperature after the warm-up operation is completed, the operations of steps ST51, ST52, ST53, ST54, ST55, ST57, ST58, ST61, ST62 are performed. By being repeated, the opening degree of the opening 91 is maintained, and the bypass rate gradually decreases. As a result, the proportion of the exhaust gas G that passes through the exhaust gas recirculation device cooler 130 increases, so the temperature of the exhaust gas G that reaches the intake passage 38 gradually decreases. As the temperature of the exhaust G decreases, the temperature of the exhaust G approaches the optimum temperature after the warm-up operation is completed.

  Next, as a result of repeating the operations of steps ST51, ST52, ST53, ST54, ST55, ST57, ST58, ST61, ST62 as described above, the bypass rate is 0, that is, the first valve 152 is fully closed and the second The operation in a state where the valve 153 is fully opened but the temperature of the air-fuel mixture M exceeds the optimum temperature after the warm-up operation is completed will be described.

  In this state, since the bypass rate is 0%, the opening degree of the opening 91 is minimum, and the temperature of the air-fuel mixture M exceeds the optimum temperature after completion of the warm-up operation, the control unit 190d The process proceeds from ST61 to step ST63.

  In step ST63, the control unit 190d determines whether or not the opening degree of the opening 91 is the maximum. Specifically, the control unit 190d detects the opening degree of the opening 91 based on the detection result of the rotation angle detection sensor 102a. In this description, since the opening degree of the opening 91 is minimum, the control unit 190d detects that the opening degree of the opening 91 is minimum, and determines that the opening degree of the opening 91 is not maximum. Then, the process proceeds to step ST64.

  In step ST64, the control unit 190d maintains the bypass rate. Then, the control unit 10d increases the opening degree of the opening 91 based on the detection result of the rotation angle detection sensor 102a while controlling the driving device 102. Specifically, the control unit 190d rotates the predetermined angle α in the direction of opening the rotation shaft 103 based on the detection result of the rotation angle detection sensor 102a while controlling the driving device 102. Since the predetermined angle α is the same as that described in the second embodiment, a description thereof will be omitted. Then, the process returns to step ST51.

  After the warm-up operation is completed, when the temperature of the air-fuel mixture M exceeds the optimum temperature after the completion of the warm-up operation and the bypass rate is 0%, as described above, steps ST51, ST52, ST53, ST54, ST55, ST56 are performed. , ST57, ST58, ST61, ST63, ST64 are repeated, so that the opening degree of the opening 91 gradually increases. As a result, the exhaust G is cooled.

  Next, in the state where the temperature of the air-fuel mixture M becomes lower than the optimum temperature for completion of warm-up operation by the above operation, that is, after the completion of warm-up operation of the internal combustion engine 20, the temperature of the air-fuel mixture M is optimum after completion of warm-up operation. After exceeding the temperature, the operation in a state where the temperature is cooled by the above operation and becomes lower than the optimum temperature for completing the warm-up operation will be described.

  In this state, the opening degree of the opening 91 is not the minimum, and the bypass rate is 0%. For this reason, the control unit 190d proceeds from step ST58 to step ST59. In step ST59, the control unit 190d determines that the opening degree of the opening 91 is not the minimum, and proceeds to step ST65.

  In step ST65, the control unit 190d controls the drive device 102 to reduce the opening degree of the opening 91 while maintaining the bypass rate. Specifically, the control unit 190d rotates the predetermined angle α in a direction to close the rotation shaft 103 based on the detection result of the rotation angle detection sensor 102a while controlling the driving device 102. Then, the process returns to step ST51.

  After the warm-up operation of the internal combustion engine 20 is completed, after the temperature of the air-fuel mixture M has exceeded the optimum temperature after the completion of the warm-up operation, and is cooled by the above operation to become less than the optimum temperature for completion of the warm-up operation, the above steps are performed. By repeating the operations of ST51, ST52, ST53, ST54, ST55, ST57, ST58, ST59, and ST65, the opening degree of the opening 91 is gradually reduced, so that the exhaust gas G is heated. As a result, the temperature of the air-fuel mixture M is raised.

  Next, the operation in a state where the temperature of the air-fuel mixture M has not been raised to the optimum temperature after completion of the warm-up operation although the opening degree of the opening 91 is minimized by the above operation will be described. In this state, the bypass rate is 0%, and the opening degree of the opening 91 is minimum.

  In this state, in step ST59, the control unit 190d determines that the opening degree of the opening 91 is the minimum, and proceeds to step ST60. In step ST60, the control unit 190d determines whether or not the bypass rate is 100%. Specifically, the control unit 190d detects the bypass rate based on the detection result of the rotation angle detection sensor 157. In this description, since the bypass rate is 0%, the control unit 190d determines that the bypass rate is not 100%, and proceeds to step ST66.

  In step ST66, the control unit 190d maintains the opening degree of the opening 91 based on the detection result of the rotation angle detection sensor 102a while controlling the driving device 102. The control unit 190d controls the first and second valves 152 and 153 so that the bypass rate increases. Specifically, the control unit 190d controls the driving device 151 and, based on the detection result of the rotation angle detection sensor 157, opens the rotating shaft 155 in the direction in which the first valve 152 opens and the second valve 153 closes. It rotates by a predetermined angle β. When the rotation shaft 155 is rotated by a predetermined angle β, the process returns to step ST51.

  The operation of steps ST51, ST52, ST53, ST54, ST55, ST57, ST58, ST59, ST60, ST67 is repeated until the temperature of the air-fuel mixture M is raised to the minimum temperature after completion of the warm-up operation. As a result, the exhaust gas G is heated by gradually increasing the bypass rate, so that the air-fuel mixture M is heated to the optimum temperature after the warm-up operation is completed.

  When the driving of the internal combustion engine 20 is stopped, the process proceeds from step ST51 to step ST67. In step ST67, the control unit 190d sets the flag to 0, and the control ends.

  In this embodiment, the same effects as those of the second and fourth embodiments can be obtained. Further, the temperature of the air-fuel mixture M can be adjusted to the optimum temperature after the warm-up operation is completed after the warm-up operation of the internal combustion engine 20 is completed.

  Further, by using the exhaust gas recirculation device cooling device 130 and the exhaust gas recirculation device cooling device bypass passage 140 in order to adjust the temperature of the air mixture M, the temperature of the air mixture M can be adjusted efficiently. .

  Further, when the temperature of the air-fuel mixture M is lower than a predetermined temperature, the opening 91 is closed with priority over the increase of the bypass rate, so that the temperature of the catalyst 72 is increased to an active state earlier when the air-fuel mixture M is heated. This is advantageous in terms of exhaust purification.

  Further, when the temperature of the air-fuel mixture M is higher than a predetermined temperature, the opportunity to open the opening 91 is reduced by giving priority to the reduction of the bypass rate, and the temperature of the catalyst 72 is not lowered as much as possible when cooling the air-fuel mixture M. Since the active state can be maintained, it is more advantageous in terms of exhaust purification.

  In addition, said predetermined temperature is the predetermined temperature said by this invention, and in this embodiment, it is the optimal temperature after completion of warming-up operation as an example.

  In each of the above embodiments, the internal combustion engine 20 has a structure including four cylinders as an example of a plurality of cylinders. However, in each of the above embodiments, the internal combustion engine 20 may have a structure including only a single cylinder (one cylinder). In this case, the exhaust system 40 does not include an exhaust manifold.

  In the case of this structure, a part of the exhaust passage 41 is used similarly to the exhaust manifold described in the above embodiments. A part of the exhaust passage 41 is preferably a position in the vicinity of the combustion chamber in the exhaust passage 41. For example, the exhaust passage 41 is a portion connected to the combustion chamber.

  The catalyst device 70 is disposed at a position spaced apart from a part of the exhaust passage 41 and at a position where at least a part overlaps the part of the exhaust passage in the vertical direction of the vehicle body. A cover member 90 covers the part of the exhaust passage 41 and the catalyst device 70. The positional relationship between the part of the exhaust passage 41 used in place of the exhaust manifold 42 and the catalytic device 70 may be the same as the positional relationship between the exhaust manifold 42 and the catalytic device 70 described in the above embodiments. Similarly, the positional relationship between the part of the exhaust passage 41 used instead of the exhaust manifold 42 and the cover member 90 is the same as the positional relationship between the exhaust manifold 42 and the cover member 90 described in the above embodiments. Good. As a result, even if the internal combustion engine 20 has a single cylinder structure in each of the above-described embodiments, the same operations and effects as those of the respective embodiments can be obtained.

  When the internal combustion engine 20 has a single cylinder structure and is not provided with an exhaust manifold, the exhaust G discharged from one combustion chamber flows in the exhaust passage 41. For this reason, the exhaust gas G flows through the exhaust passage 41 almost always, but not always. In other words, the exhaust passage 41 has an action similar to that obtained by the merging portion 48 of the exhaust manifold 42.

  In the first to fifth embodiments, the control units 190, 190c, and 190d have two functions of a control unit and a temperature rise determination unit in the present invention. However, it is not limited to this. Even if there is a determination unit different from the control units 190, 190 c, and 190 d that determines whether or not the temperature of the catalyst device 70 needs to be increased based on the detection result of the refrigerant temperature detection sensor 180 as the temperature increase determination unit. Good.

  In the first to fifth embodiments, the optimum temperature during warm-up operation and the optimum temperature after completion of warm-up operation are used as examples of the predetermined temperature referred to in the present invention. An example of the optimum temperature during the warm-up operation and the optimum temperature after the completion of the warm-up operation are described in detail in the second embodiment. However, the predetermined temperature may be one temperature having no range, for example.

  The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments. For example, you may delete some components from all the components shown by embodiment mentioned above. Furthermore, you may combine the component covering different embodiment suitably.

  DESCRIPTION OF SYMBOLS 20 ... Internal combustion engine, 21-24 ... Combustion chamber, 40 ... Exhaust system, 41 ... Exhaust passage, 42 ... Exhaust manifold (a part of exhaust passage), 50, 50a, 50b, 50c, 50d ... Exhaust recirculation device, 70 ... Catalytic device, 90 ... cover member, 91 ... opening, 101 ... opening / closing plate (opening / closing door member), 102 ... driving device (temperature adjusting means), 102a ... rotation angle detection sensor (temperature adjusting means), 120 ... exhaust gas recirculation passage, DESCRIPTION OF SYMBOLS 130 ... Exhaust gas recirculation device cooler (cooling device), 140: Exhaust gas recirculation device cooler bypass (detour passage), 170, 170a, 170c, 70d ... Control means, 180 ... Refrigerant temperature detection sensor (temperature rise determination means, refrigerant temperature) Detection means), 190, 190a, 190c, 190d ... control unit (temperature rise determination means), 200 ... mixture temperature detection sensor (mixture temperature detection means), C ... cooling water (cooling) ), G ... exhaust, M ... the air-fuel mixture.

Claims (7)

An exhaust passage communicating with the combustion chamber of the internal combustion engine and constituting a part of the exhaust system;
An exhaust gas recirculation passage for leading a part of the exhaust gas from the exhaust system to the intake passage;
A catalyst device formed in the exhaust gas recirculation passage;
A cover member covering a part of the exhaust passage and the catalyst device;
An opening and closing door member that adjusts the opening of the opening by opening and closing the opening formed in the cover member;
Temperature adjusting means for controlling the opening / closing door member to adjust the temperature of the exhaust gas led to the intake passage;
An exhaust gas recirculation apparatus comprising: control means for controlling the temperature adjusting means. Comprising a temperature increase determination means for determining whether or not the catalyst apparatus needs to be heated;
The said control means controls the said opening-and-closing door member and makes the opening degree of the said opening small, when the said temperature rising determination means determines that the temperature rising of the said catalyst apparatus is required. The exhaust gas recirculation apparatus according to 1. The temperature increase determination means includes refrigerant temperature detection means for detecting the temperature of the refrigerant that cools the combustion chamber, and the temperature of the catalyst device is increased based on the temperature of the refrigerant detected by the refrigerant temperature detection means. The exhaust gas recirculation apparatus according to claim 2, wherein it is determined whether it is necessary or unnecessary. An air-fuel mixture temperature detecting means for detecting the temperature of the air-fuel mixture of the air supplied to the combustion chamber and the exhaust,
The exhaust gas recirculation apparatus according to any one of claims 1 to 3, wherein the control means controls the opening degree of the opening so that the temperature of the air-fuel mixture becomes a predetermined temperature. . A cooling device provided downstream of the catalyst device in the exhaust gas recirculation passage for cooling the exhaust gas;
A bypass passage that is provided downstream of the catalyst device in the exhaust gas recirculation passage and bypasses the cooling device,
The exhaust gas according to claim 4, wherein the control means controls the opening degree of the opening and the flow rate of the exhaust gas flowing through the bypass passage so that the temperature of the air-fuel mixture becomes the predetermined temperature. Reflux apparatus. The said control means changes the flow volume of the said exhaust gas which flows through the said bypass path, after making the opening degree of the said opening into the minimum, when the temperature of the said air-fuel mixture is smaller than the said predetermined temperature. The exhaust gas recirculation device described. The said control means changes the opening degree of the said opening, after making the flow volume of the said exhaust_gas | exhaustion which flows through the said bypass path into 0, when the temperature of the said air-fuel mixture is larger than the said predetermined temperature. The exhaust gas recirculation device according to claim 6.

Images