JP6214447B2 - Catalytic converter cooling mechanism - Google Patents

Description

  The present invention relates to a cooling mechanism for a catalytic converter, and more particularly, to a cooling mechanism for a catalytic converter that incorporates a catalyst and has an exhaust inlet and an exhaust outlet.

  A catalytic converter is a device that is generally provided in an exhaust passage of exhaust gas discharged from an internal combustion engine, and purifies harmful components in the exhaust gas by passing the exhaust gas through a catalyst carrier containing a catalyst. .

  Since such a catalytic converter needs to activate the catalytic function by increasing the catalyst temperature, it may be arranged in the vicinity of the internal combustion engine in order to increase the catalyst temperature according to the combustion temperature in the internal combustion engine. is there.

  On the other hand, when the catalyst temperature becomes excessively high, the catalyst is thermally deteriorated. In such a case, it is necessary to lower the catalyst temperature. As such countermeasures, various techniques for cooling the catalyst to lower the catalyst temperature have been proposed.

  Patent Document 1 discloses an air cooling mechanism for a catalytic converter that cools the catalytic converter with running air or cooling air from a radiator fan.

  The air cooling mechanism of the catalytic converter is formed with an outer pipe that covers a part of the outer side of the catalytic converter and introduces cooling air into a space between the outer pipe and the outer side of the catalytic converter. , And control means for controlling the cooling air introduction means. The cooling air introduction means introduces cooling air from the running air and the radiator fan into the space to cool the catalyst via the catalytic converter.

JP 7-279653 A

  By the way, for example, due to misfire due to a malfunction of the ignition device, a large amount of unburned gas flows into the catalytic converter, or the traveling wind introduced at the time of climbing a steep slope decreases, so that the catalyst temperature becomes high. Sometimes.

  In such a case, it is necessary to cool the catalyst. However, depending on the air cooling mechanism as described in Patent Document 1, the catalyst temperature is appropriately controlled in a wide operating range such as when the internal combustion engine is under low load and when under high load. Therefore, when the catalyst temperature rises excessively, there is a concern that the catalyst temperature cannot be lowered efficiently.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a cooling mechanism for a catalytic converter that can efficiently reduce the catalyst temperature and suppress the thermal deterioration of the catalyst.

  The cooling mechanism for a catalytic converter according to the first aspect of the present invention for solving the above-described problem is a cooling of a catalytic converter that cools a catalytic converter that includes a catalyst and includes a catalyst case having an exhaust inlet and an exhaust outlet. In the mechanism, the catalytic converter includes a cooling liquid case that covers a part or the whole of the catalyst case via a gap with an outer surface of the catalyst case, and a cooling source and cooling liquid from the cooling source are supplied to the gap. A supply path to be supplied; a first valve provided in the supply path for communicating or blocking between the cooling source and the gap; and a recovery path for supplying the coolant supplied to the gap to the cooling source. A second valve provided in the recovery path for communicating or blocking between the gap and the cooling source, and the first valve and the second valve based on a preset catalyst temperature of the catalyst. Control to open and close The controller is configured to open both the first valve and the second valve when the catalyst temperature rises to a preset catalyst temperature, and to set the catalyst temperature above the preset catalyst temperature. The first valve is closed when the catalyst temperature is lowered, and the second valve is closed after the first valve is closed.

  According to this configuration, the first valve is opened by the control unit based on the preset catalyst temperature, and the coolant is supplied to the gap of the catalytic converter via the supply path, and the second valve is supplied by the control unit. Is released and the coolant supplied to the gap of the catalytic converter is supplied again to the cooling source.

  By supplying the cooling liquid to the gap of the catalytic converter, the catalyst is cooled, and the cooling liquid that has cooled the catalyst is supplied again to the cooling source through the recovery path.

  As described above, since the catalyst is cooled in the process of repeatedly supplying the coolant from the cooling source and supplying the coolant again to the cooling source, the catalyst temperature can be efficiently reduced. Thermal degradation can be prevented.

  On the other hand, when the catalyst temperature is lower than the preset catalyst temperature, the first valve is closed by the control unit, and the second valve is closed by the control unit after the first valve is closed. Then, the coolant that is heated and steamed by being supplied to the gap of the catalytic converter and cooling the catalyst is sealed in the gap in a sealed state.

  As a result, the heat dissipation of the catalyst is suppressed by the steamed coolant, so that, for example, even when the internal combustion engine is restarted in a cold state, warm-up is hindered by the liquid phase coolant. There is no. Therefore, the vehicle can be driven in a state where the catalytic function is activated early.

  According to a second aspect of the present invention, in the cooling mechanism for the catalytic converter according to the first aspect, the cooling source is a heat radiator that radiates heat of the internal combustion engine of the vehicle.

  According to this configuration, since the radiator that radiates the heat of the internal combustion engine is used as the cooling source of the catalytic converter, the catalyst of the catalytic converter is cooled by the cooling liquid cooled by the radiator, while the cooling of the catalyst The internal combustion engine is warmed up by the heated coolant.

  Accordingly, when the catalyst is cooled according to the cooling request and the internal combustion engine is supercooled, the internal combustion engine is warmed up, so that a good running state of the vehicle is ensured.

  According to a third aspect of the present invention, in the cooling mechanism for the catalytic converter according to the first aspect, the cooling source is a heat exchanger that is provided in a transmission of a vehicle and exchanges heat with the heat of the transmission. It is characterized by that.

  According to this configuration, since the heat exchanger provided in the transmission is used as a cooling source for the catalytic converter, the catalyst of the catalytic converter is cooled by the coolant cooled by the heat exchanger, while the cooling of the catalyst is performed. The transmission is warmed up by the coolant heated by.

  Therefore, when the catalyst is cooled in response to the cooling request and the transmission is supercooled, the transmission is warmed up, so that a good running state of the vehicle is ensured.

  According to the present invention, based on the catalyst temperature, the control unit opens the first valve and supplies the coolant to the gap of the catalytic converter through the supply path, and the control unit opens the second valve. The coolant supplied to the gap of the catalytic converter is supplied again to the cooling source.

  As described above, in the process of repeatedly supplying the coolant from the cooling source and supplying the coolant again to the cooling source, the catalyst is cooled according to the cooling request. Therefore, since the catalyst temperature can be efficiently lowered to prevent thermal deterioration of the catalyst, a good running state of the vehicle is ensured.

  On the other hand, when the first valve is closed and the second valve is subsequently closed, the cooling liquid supplied to the gap of the catalytic converter and heated and vaporized by cooling the catalyst is sealed in the gap in a sealed state. .

  Thereby, since the heat radiation of the catalyst is suppressed by the steamed coolant, for example, even when the internal combustion engine is restarted in a cold state, the catalyst temperature can be increased satisfactorily. Therefore, the vehicle can be run with the catalyst function activated at an early stage.

It is a figure explaining the outline of the cooling mechanism of the catalytic converter which concerns on 1st Embodiment of this invention. Similarly, it is a figure explaining the outline of the cooling process of the catalytic converter by the cooling mechanism of the catalytic converter which concerns on this Embodiment. Similarly, it is a figure explaining the outline of the cooling process of the catalytic converter by the cooling mechanism of the catalytic converter which concerns on this Embodiment. It is a figure explaining the outline of the cooling mechanism of the catalytic converter which concerns on 2nd Embodiment of this invention.

  Next, each embodiment of the present invention will be described with reference to FIGS. In the embodiment, a case where the catalytic converter is a catalytic converter disposed in an exhaust system of an internal combustion engine of a vehicle will be described as an example.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a diagram for explaining the outline of the cooling mechanism of the catalytic converter according to the present embodiment. As illustrated, the catalytic converter cooling mechanism 1 includes a catalytic converter 10 to be cooled and a cooling circuit 20 for cooling the catalytic converter 10.

  The catalytic converter 10 includes a catalyst case 11, a catalyst carrier 12 accommodated in the catalyst case 11, and a coolant case 13 that covers all of the catalyst case 11.

  The catalyst case 11 is an exhaust gas introduction port 11b that is an exhaust gas introduction port that projects and opens toward the upstream side of the catalyst case 11 indicated by an arrow U, and an exhaust gas that projects and opens toward a downstream side indicated by an arrow D. It is formed in a substantially cylindrical shape having an exhaust gas discharge port 11c which is a discharge port.

  The catalyst carrier 12 is formed in a cylindrical shape that fits into the inner surface of the catalyst case 11 and is accommodated in the catalyst case 11, and includes cells 12 a that are partitioned by partition walls that extend from the upstream U to the downstream D. It has a honeycomb shape. The catalyst carrier 12 contains a catalyst such as Pt, Pd, or Rh.

  The coolant case 13 is formed in a substantially cylindrical shape that covers the entire catalyst case 11 via the outer surface 11a of the catalyst case 11 and the gap S.

  The cooling circuit 20 includes a radiator 21 that serves as a cooling source and a radiator that radiates heat from a cooling device 21 that is a cooling source and an engine 30 that is an internal combustion engine of a vehicle.

  The cooling device 21 is a device that cools the coolant (coolant) with the traveling wind W1 introduced into the vehicle through the grill.

  On the other hand, the radiator device 31 is a device that cools the coolant (coolant) with the traveling wind W2 introduced into the vehicle via the grill, and cools the engine 30 with the coolant. In the present embodiment, The cooling device 21 is selectively used as a cooling source for the coolant supplied to the catalytic converter 10.

  In the present embodiment, the coolant of the radiator device 31 is supplied to the water jacket of the engine 30 by the electromagnetic water pump 32 to cool the engine 30.

  Further, the cooling circuit 20 includes a supply path 22 for supplying the coolant from the cooling device 21 or the radiator device 31 to the gap S between the catalyst case 11 and the coolant case 13, and the coolant supplied to the gap S as a cooling device. 21 or a recovery passage 25 for supplying to the radiator device 31 is provided.

  The supply path 22 includes a main supply path 22A between the cooling device 21 and the gap S on the exhaust gas introduction port 11b side of the catalytic converter 10, and a sub supply path 22B between the radiator device 31 and the main supply path 22A. .

  The main supply path 22A of the supply path 22 includes an electromagnetic water pump 23 and a first valve 24 that opens or closes the cooling apparatus 21 and the gap S by opening and closing, and the gap between the cooling apparatus 21 and the catalytic converter 10. They are arranged in order toward S.

  The sub supply path 22B is disposed from the radiator device 31 between the cooling device 21 and the water pump 23 in the main supply path 22A, and allows the coolant from the radiator device 31 to flow into the main supply path 22A.

  The recovery path 25 includes a main recovery path 25 </ b> A between the gap S on the exhaust gas discharge port 11 c side of the catalytic converter 10 and the cooling device 21.

  The main recovery path 25A includes a second valve 26 that opens or closes the gap S and the cooling device 21 by opening and closing, a gas-liquid separation tank 27 that separates the cooling liquid into a liquid phase and a gas phase, and a cooling liquid A three-way valve 28 that selectively switches the recovery path between the cooling device 21 and the radiator device 31 is disposed in order from the gap S of the catalytic converter 10 toward the cooling device 21.

  On the other hand, the recovery path 25 includes a sub-recovery path 25B disposed between the three-way valve 28 and the radiator device 31, and when the coolant recovery path is switched to the radiator device 31 side by the three-way valve 28. The coolant supplied to the gap S is recovered by the radiator device 31 via the sub recovery path 25B.

  In the cooling circuit 20 configured as described above, the supply of the coolant to the catalytic converter 10 and the recovery of the coolant from the catalytic converter 10 are performed by opening and closing the first valve 24 and the second valve 26, and the cooling device 21 or The selective recovery path for the coolant to the radiator device 31 is switched by the three-way valve 28.

  The opening / closing control of the first valve 24 and the second valve 26 and the switching control of the third valve 28 are controlled by a control unit 40 provided in the cooling circuit 20.

  The control unit 40 controls the opening and closing of the first valve 24 and the second valve 26 based on a preset catalyst temperature, and the three-way valve based on the preset catalyst temperature and the operating state of the engine 30. A control program for controlling the switching of 28 is stored.

  In the present embodiment, the catalyst temperature is detected by, for example, a temperature sensor (not shown) provided in the catalytic converter 10, and the operating status of the engine 30 is grasped based on, for example, the rotational speed of the engine 30.

  Next, the cooling process of the catalytic converter 10 by the cooling circuit 20 according to the present embodiment will be described.

  For example, when the vehicle temperature starts and the catalyst temperature detected by the temperature sensor is equal to or lower than a preset catalyst temperature, the first valve 24 and the second valve 26 are closed.

  In this state, the catalyst temperature rises due to the combustion temperature of the engine 30. At this time, since the first valve 24 and the second valve 26 are closed, the gap S of the catalytic converter 10 is sealed. Thereby, the heat dissipation of a catalyst is suppressed and activation of a catalyst function is accelerated | stimulated.

  Next, for example, when unburned gas flows into the catalytic converter 10 due to misfiring due to a malfunction of the ignition device, or when traveling wind introduced when climbing a steep slope decreases, the catalyst temperature rises excessively. To do.

  When the temperature sensor detects a preset catalyst temperature due to an excessive increase in the catalyst temperature, the first valve 24 and the second valve 26 are opened by the controller 40 as shown in FIG.

  On the other hand, in this case, for example, when it is determined that the engine 30 is warmed up by running of the vehicle based on the rotational speed of the engine 30, the three-way valve 28 is set by the control unit 40. The recovery path is selected so that the coolant is supplied to the cooling device 21 by switching.

  When the first valve 24 is opened, the coolant cooled by the cooling device 21 is supplied by the water pump 23 to the gap S between the catalyst case 11 and the coolant case 13 of the catalytic converter 10 via the main supply path 22A. Is done.

  The coolant supplied into the gap S cools the catalyst built in the catalyst carrier 12 via the catalyst case 11 and lowers the catalyst temperature. The coolant supplied to the gap S flows down from the upstream side U of the catalytic converter 10 toward the downstream side D.

  The coolant that has flowed down flows into the gas-liquid separation tank 27 via the main recovery path 25A when the second valve 26 is opened, and is separated into a liquid phase and a gas phase.

  The cooling liquid separated into the liquid phase is supplied to the cooling device 21 via the main recovery path 25A because the recovery path is switched to the cooling device 21 side by the three-way valve 28. Cooled again by the introduced traveling wind W1 and supplied to the gap S of the catalytic converter 10 via the main supply path 22A.

  Next, for example, when the operation of the engine 30 is stopped or during normal driving of the vehicle where the catalyst is cooled by the coolant and the catalyst temperature is equal to or lower than the preset catalyst temperature, as shown in FIG. The first valve 24 is closed by the control unit 40 to shut off the main supply path 22A, the operation of the water pump 23 is stopped, and the supply of the coolant to the gap S is stopped.

  After the elapse of a predetermined time T in which the coolant supplied to the gap S of the catalytic converter 10 cools the catalyst and vaporizes it before the first valve 24 is closed, the second valve 26 is closed by the controller 40 and the main recovery is performed. The passage 25A is blocked and the recovery of the coolant is stopped.

  The predetermined time T is a difference time between the closing timing of the first valve 24 and the closing timing of the second valve 26, and in this embodiment, the cooling supplied to the gap S before the first valve 24 is closed. This is understood as the time required for the liquid to vaporize.

  That is, when the temperature sensor detects a catalyst temperature equal to or lower than a preset catalyst temperature, when the first valve 24 is closed and a predetermined time T after the first valve 24 is closed passes, The second valve 26 is closed because it is determined that the water has been vaporized by cooling.

  Since the first valve 24 is closed and the second valve 26 is subsequently closed, the vaporized coolant is sealed in the gap S between the catalyst case 11 and the coolant case 13 in the catalytic converter 10. The heat dissipation of the catalyst is suppressed by the steamed coolant.

  Next, for example, when the temperature sensor detects a preset catalyst temperature due to an increase in the catalyst temperature, the first valve 24 and the second valve 26 are opened by the control unit 40 as shown in FIG.

  On the other hand, in this case, for example, when it is determined that the engine 30 is supercooled due to the introduction of traveling wind due to high-speed traveling of the vehicle based on the rotational speed of the engine 30, the three-way valve 28 is controlled by the control device 40. The recovery path is selected so that the coolant is supplied to the radiator device 31 by switching.

  When the first valve 24 is opened, the coolant cooled by the radiator device 31 flows into the main supply passage 22A from the sub supply passage 22B, and the catalyst case 11 and the coolant of the catalytic converter 10 are connected to the main supply passage 22A. The coolant is supplied to the gap S with the case 13 by the water pump 23.

  The coolant supplied in the gap S cools the catalyst built in the catalyst carrier 12 through the catalyst case 11 to lower the catalyst temperature and is heated by the heat of the catalyst. The coolant supplied to the gap S flows down from the upstream side U of the catalytic converter 10 toward the downstream side D.

  The heated coolant flows into the gas-liquid separation tank 27 through the main recovery path 25A by opening the second valve 26, and is separated into a liquid phase and a gas phase.

  The coolant separated into the liquid phase is switched to the radiator device 31 side by the three-way valve 28, and therefore flows into the water jacket of the engine 30 via the sub-recovery passage 25 </ b> B. Circulate.

  Since the coolant flowing into the water jacket is heated to a high temperature, the coolant 30 circulates in the engine 30 to warm up the supercooled engine 30.

  The coolant that warms up the engine 30 is supplied to the radiator device 31 by the water pump 32, and is cooled again by the traveling air W2 introduced from the grill in the radiator device 31, and the catalytic converter 10 is supplied via the sub supply path 22B. To the gap S.

  In the cooling mechanism 1 of the catalytic converter 10 configured as described above, when the catalyst temperature rises and the temperature sensor detects a preset catalyst temperature, the first valve 24 is opened by the control unit 40 via the main supply path 22A. Then, the coolant is supplied to the gap S of the catalytic converter 10 to cool the catalyst.

  Since the second valve 26 is opened by the control unit 40, the coolant that has cooled the catalyst is supplied to the cooling device 21 or the radiator device 31 via the recovery path 25 and cooled again, and again for cooling the catalyst. Provided.

  As described above, by repeating the cooling and re-cooling steps, the cooling liquid cools the catalyst built in the catalyst carrier 12 via the catalyst case 11, so that the catalyst temperature can be lowered efficiently. The thermal deterioration of the catalyst can be prevented.

  When the radiator device 31 is used as a cooling source for the catalytic converter 10 selectively with the cooling device 21, the catalyst of the catalytic converter 10 is cooled by the coolant cooled by the radiator device 31, while being heated by cooling the catalyst. The engine 30 is warmed up by the cooled coolant.

  Therefore, the catalyst is cooled according to the cooling request, and, for example, when the engine 30 is supercooled due to high-speed running of the vehicle, the engine 30 is warmed up, so that a good running state of the vehicle is ensured. Is done.

  On the other hand, for example, when the operation of the engine 30 is stopped, when the catalyst temperature is equal to or lower than a preset temperature, the first valve 24 is closed by the control unit 40, and after the predetermined time T has elapsed, the control unit 40 As a result, the second valve 26 is closed.

  As a result, the cooling liquid heated by the catalyst by cooling the catalyst is vaporized, and the vaporized cooling liquid is sealed in the gap S in a sealed state, so that the heat dissipation of the catalyst is suppressed by the vaporized cooling liquid. The

  Therefore, since the catalyst temperature rises favorably immediately after the engine 30 is restarted, the vehicle can be run with the catalyst function activated.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG.

  In the present embodiment, only the configuration of the cooling source different from that of the first embodiment will be described, and the rest of the configuration is the same as that of the first embodiment. Detailed description thereof is omitted.

  As shown in the figure, in the present embodiment, in the cooling circuit 20, a heat exchanger 51 that is provided in the transmission 50 of the vehicle and exchanges heat with the transmission 50 is used as a cooling source.

  The heat exchanger 51 is a device that cools the coolant (coolant) with traveling wind introduced into the vehicle through the grill and cools the transmission 50 with the coolant. In the present embodiment, The cooling device 21 is selectively used as a cooling source for the coolant supplied to the catalytic converter 10.

  In the present embodiment, the coolant of the heat exchanger 51 is supplied to the water jacket of the transmission 50 by the electromagnetic water pump 52 to cool the transmission 50.

  Next, the cooling process of the catalytic converter 10 by the cooling circuit 20 according to the present embodiment will be described.

  For example, when the temperature sensor detects a preset catalyst temperature due to an increase in the catalyst temperature, the first valve 24 and the second valve 26 are opened by the control unit 40.

  On the other hand, in this case, for example, when it is determined that the transmission 50 is supercooled due to the introduction of traveling wind due to high-speed traveling of the vehicle based on the number of rotations of the transmission 50, the three-way valve is controlled by the controller 40. 28 is switched, and the recovery path is selected so that the coolant is supplied to the heat exchanger 51.

  When the first valve 24 is opened, the coolant cooled by the heat exchanger 51 flows into the main supply passage 22A from the sub supply passage 22B, and the water pump 23 causes the catalyst case 11 and the coolant case 13 of the catalytic converter 10 to The gap S is supplied via the main supply path 22A.

  The coolant supplied in the gap S cools the catalyst built in the catalyst carrier 12 through the catalyst case 11 to lower the catalyst temperature and is heated by the heat of the catalyst. The coolant supplied to the gap S flows down from the upstream side U of the catalytic converter 10 toward the downstream side D.

  The heated coolant flows into the gas-liquid separation tank 27 through the main recovery path 25A by opening the second valve 26, and is separated into a liquid phase and a gas phase.

  Since the recovery path is switched to the heat exchanger 51 side by the three-way valve 28, the coolant separated into the liquid phase flows into the water jacket of the transmission 50 through the sub-recovery path 25B, and the transmission 50 Circulate inside.

  Since the coolant that has flowed into the water jacket is heated to a high temperature, the coolant 50 circulates in the transmission 50, whereby the overcooled transmission 50 is warmed up.

  The coolant that warms up the transmission 50 is supplied to the heat exchanger 51 by the water pump 52, and is cooled again by the traveling air introduced from the grill in the heat exchanger 51, and the catalyst is passed through the sub supply path 22B. It is supplied to the gap S of the converter 10.

  In the cooling mechanism 1 of the catalytic converter 10 having the above configuration, when the heat exchanger 51 is selectively used as the cooling source of the catalytic converter 10 with the cooling device 21, the catalytic converter is cooled by the cooling liquid cooled by the heat exchanger 51. While the ten catalysts are cooled, the transmission 50 is warmed up by the coolant heated by the cooling of the catalyst.

  Therefore, the catalyst is cooled in response to the cooling request, and the transmission device 50 is warmed up when the transmission device 50 is supercooled due to high-speed traveling of the vehicle. Is secured.

  In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning of invention. In the above embodiment, the case where the cooling water case 13 covers the entire catalyst case 11 has been described. However, the cooling water case 13 may be configured to cover only a part of the catalyst case 11.

  In the above embodiment, the case where the first valve 24 and the second valve 26 are controlled to be opened and closed by the control unit 40 based on the catalyst temperature detected by the temperature sensor that detects the temperature of the catalyst has been described. The catalyst temperature may be estimated based on an exhaust gas sensor that detects the temperature or a pressure sensor that detects the pressure of the exhaust gas. Further, the catalyst temperature may be estimated based on the accelerator opening or the engine speed. .

DESCRIPTION OF SYMBOLS 1 Cooling mechanism of catalytic converter 10 Catalytic converter 11 Catalyst case 12 Catalyst carrier 13 Coolant case 20 Cooling circuit 21 Cooling device (cooling source)
22 supply path 22A main supply path 22B sub supply path 24 first valve 25 recovery path 25A main recovery path 25B sub recovery path 26 second valve 28 three-way valve 30 engine (internal combustion engine)
31 Radiator device (heat radiator)
40 Control Unit 50 Transmission 51 Heat Exchanger

Claims (3)

In the catalytic converter cooling mechanism for cooling the catalytic converter with the catalyst built-in and having a catalyst case having an exhaust inlet and an exhaust outlet,
The catalytic converter includes a coolant case that covers a part or all of the catalyst case through a gap with an outer surface of the catalyst case,
A cooling source;
A supply path for supplying the coolant from the cooling source to the gap;
A first valve provided in the supply path for communicating or blocking between the cooling source and the gap;
A recovery path for supplying the cooling liquid supplied to the gap to the cooling source;
A second valve provided in the recovery path to communicate or block between the gap and the cooling source;
A controller that opens and closes the first valve and the second valve based on a preset catalyst temperature of the catalyst,
The control unit
When the catalyst temperature rises to a preset catalyst temperature, both the first valve and the second valve are opened, and when the catalyst temperature falls below the preset catalyst temperature, the first valve is opened. A catalytic converter cooling mechanism characterized in that the valve is closed and the second valve is closed after the first valve is closed. The cooling source is
The cooling mechanism for a catalytic converter according to claim 1, wherein the cooling mechanism is a radiator that dissipates heat from an internal combustion engine of a vehicle. The cooling source is
2. The cooling mechanism for a catalytic converter according to claim 1, wherein the cooling mechanism is a heat exchanger that is provided in a transmission of a vehicle and exchanges heat with the transmission.

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