JP2010242645A - Cooling device for internal combustion engine - Google Patents

Abstract

A cooling device for an internal combustion engine capable of suppressing overheating of an exhaust device.
In the cooling device, cooling water from the radiator is passed through the engine body as a cooling water passage for circulating cooling water between the radiator, the engine body and the cooling adapter. A fourth cooling water passage 44 that circulates to 33 and a fifth cooling water passage 45 through which the cooling water from the radiator 31 circulates to the cooling adapter 33 without passing through the engine body 10 are provided. When the water temperature of the cooling adapter 33 is higher than the reference temperature, the flow rate of the fifth cooling water passage 45 is increased compared to when the water temperature is lower than the reference temperature.
[Selection] Figure 1

Description

  The present invention relates to a cooling device for an internal combustion engine that supplies refrigerant from a refrigerant cooling device to an engine body and an exhaust device through a refrigerant passage.

As the cooling device, for example, the one described in Patent Document 1 is known.
In this cooling device, the circulation mode of the cooling water is switched according to the temperature of the cooling water that has passed through the engine body (cylinder block), and the manifold is overheated by the supply of the cooling water to the exhaust device (exhaust manifold). I try to suppress that.

JP-A-7-109923

  By the way, in the above-mentioned Patent Document 1, the cooling water cooled by the refrigerant cooling device is supplied to the exhaust manifold after passing through the engine main body. Therefore, when the temperature of the cooling water after passing through the engine main body is excessively high, When it is supplied to the manifold, it is hard to say that the cooling effect is sufficiently obtained.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a cooling device for an internal combustion engine that can suppress overheating of an exhaust device.

In the following, means for achieving the above object and its effects are described.
(1) The invention described in claim 1 is an internal combustion engine cooling device in which a refrigerant is circulated between a refrigerant cooling device, an engine body, and an exhaust device by a refrigerant passage. A first refrigerant passage through which refrigerant flows to the exhaust device via the engine body, and a second refrigerant passage through which refrigerant from the refrigerant cooling device flows to the exhaust device without passing through the engine body. When the temperature of the refrigerant around the exhaust device or the exhaust system temperature, which is the temperature of the exhaust device, is higher than a reference temperature, the temperature of the second refrigerant passage is larger than when the exhaust system temperature is lower than the reference temperature. The gist is that the flow rate of the refrigerant is increased.

  According to the present invention, the flow rate of the refrigerant in the second refrigerant passage is increased when the exhaust system temperature is higher than the reference temperature, that is, the engine body receives heat when the exhaust device is at a relatively high temperature. Since the flow rate of the refrigerant supplied to the exhaust device is increased, overheating of the exhaust device can be suppressed.

  (2) The invention according to claim 2 is the cooling apparatus for an internal combustion engine according to claim 1, wherein when the exhaust system temperature is higher than the reference temperature, the exhaust system temperature is lower than the reference temperature. The gist is that the flow rate of the refrigerant in the first refrigerant passage is reduced.

  According to the present invention, the flow rate of the refrigerant in the first refrigerant passage is reduced when the exhaust system temperature is higher than the reference temperature, that is, after the engine body receives heat when the exhaust device is in a relatively high temperature state. Since the flow rate of the refrigerant supplied to the exhaust device is reduced, overheating of the exhaust device can be more suitably suppressed.

  (3) The invention according to claim 3 is the cooling device for an internal combustion engine according to claim 1 or 2, wherein the refrigerant from the refrigerant cooling device passes through the engine body and does not pass through the exhaust device. A third refrigerant passage that circulates in the cooling device is further provided, and the flow rate of the refrigerant in the third refrigerant passage when the exhaust system temperature is higher than the reference temperature compared to when the exhaust system temperature is lower than the reference temperature. The gist is to increase the amount.

  According to the present invention, the flow rate of the refrigerant in the third refrigerant passage is increased when the exhaust system temperature is higher than the reference temperature, that is, the temperature of the engine body rises to a point where the exhaust device becomes relatively hot. Since the flow rate of the refrigerant passing through the engine body increases when the engine is running, it is possible to suppress overheating of the exhaust device and suppression of overheating of the engine body.

  (4) The invention according to claim 4 is the cooling apparatus for the internal combustion engine according to claim 3, wherein the second refrigerant passage and the third refrigerant passage are opened when the exhaust system temperature is higher than the reference temperature. The gist is that the first refrigerant passage is closed.

  According to this invention, since the first refrigerant passage is closed when the exhaust system temperature is higher than the reference temperature, that is, when the exhaust device is in a relatively high temperature state, it is supplied to the exhaust device after receiving heat in the engine body. Since the flow rate of the refrigerant to be discharged becomes “0”, it is possible to more suitably suppress the occurrence of overheating of the exhaust device.

  (5) The invention according to claim 5 is the cooling apparatus for an internal combustion engine according to any one of claims 1 to 4, wherein the exhaust device includes an exhaust manifold and an exhaust catalyst device. The cooling device supplies the refrigerant from the refrigerant cooling device to the engine body and the exhaust manifold through the refrigerant passage, and the exhaust system temperature is lower than the reference temperature and the exhaust catalyst. The gist is that when the temperature of the apparatus is higher than the catalyst reference temperature, the flow rate of the refrigerant in the second refrigerant passage is reduced compared to when the exhaust system temperature is higher than the reference temperature.

  According to the present invention, the flow rate of the refrigerant in the second refrigerant passage is reduced when the temperature of the exhaust catalyst device is higher than the catalyst reference temperature, that is, when the exhaust catalyst device is sufficiently warmed up, Since the flow rate of the refrigerant that is directly supplied from the refrigerant cooling device to the exhaust catalyst device without being interposed is reduced, the warm-up state of the exhaust catalyst device can be suitably maintained.

  (6) The invention according to claim 6 is the cooling apparatus for an internal combustion engine according to any one of claims 1 to 5, wherein the exhaust device includes an exhaust manifold and an exhaust catalyst device. The cooling device supplies the refrigerant from the refrigerant cooling device to the engine body and the exhaust manifold through the refrigerant passage, and the exhaust system temperature is lower than the reference temperature and the exhaust catalyst. When the temperature of the apparatus is higher than the catalyst reference temperature, the flow rate of the refrigerant in the first refrigerant passage is lower than when the exhaust system temperature is lower than the reference temperature and the temperature of the exhaust catalyst apparatus is lower than the catalyst reference temperature. The gist is to increase the amount.

  According to the present invention, since the flow rate of the refrigerant in the first refrigerant passage is increased when the temperature of the exhaust catalyst device is higher than the catalyst reference temperature, that is, when the exhaust catalyst device is sufficiently warmed up, Since the flow rate of the refrigerant supplied to the exhaust device after receiving heat increases, the warm-up state of the exhaust catalyst device can be suitably maintained.

  (7) The invention according to claim 7 is the cooling apparatus for an internal combustion engine according to any one of claims 1 to 6, wherein the exhaust device includes an exhaust manifold and an exhaust catalyst device. The cooling device supplies the refrigerant from the refrigerant cooling device to the engine main body and the exhaust manifold through the refrigerant passage, and the refrigerant from the refrigerant cooling device passes through the engine main body and the exhaust device. A third refrigerant passage that circulates through the refrigerant cooling device without passing through the exhaust gas when the exhaust system temperature is lower than the reference temperature and the temperature of the exhaust catalyst device is higher than the catalyst reference temperature. Compared to the case where the system temperature is lower than the reference temperature and the temperature of the exhaust catalyst device is lower than the catalyst reference temperature, the refrigerant flow in the third refrigerant passage There has been a subject matter to be reduced.

  According to this invention, the flow rate of the refrigerant in the third refrigerant passage is reduced when the temperature of the exhaust catalyst device is higher than the catalyst reference temperature, that is, when the exhaust catalyst device is in a sufficiently warm-up state. Since the flow rate of the refrigerant supplied to the refrigerant cooling device is increased through this, the warm-up state of the exhaust catalyst device can be suitably maintained.

  (8) The invention according to claim 8 is the cooling apparatus for an internal combustion engine according to claim 7, wherein the exhaust system temperature is lower than the reference temperature, and the temperature of the exhaust catalyst apparatus is higher than the catalyst reference temperature. In some cases, the second refrigerant passage and the third refrigerant passage are closed and the first refrigerant passage is opened.

  According to the present invention, when the temperature of the exhaust catalyst device is higher than the catalyst reference temperature, the exhaust device is not cooled by the refrigerant from the second refrigerant passage, so that the warm-up state of the exhaust catalyst device is suitably maintained. Will be able to.

  (9) The invention according to claim 9 is the cooling apparatus for an internal combustion engine according to any one of claims 1 to 8, wherein the exhaust system temperature is lower than the reference temperature and the temperature of the engine body is lower. The gist is that the flow rate of the refrigerant in the second refrigerant passage is reduced when the exhaust system temperature is lower than the reference temperature when the temperature is lower than the main body reference temperature.

  According to the present invention, the flow rate of the refrigerant in the second refrigerant passage is reduced when the temperature of the engine main body is lower than the main body reference temperature, that is, a comparison when the engine main body is not sufficiently warmed up. Since the amount of the low-temperature refrigerant supplied to the exhaust device is reduced, it is possible to suppress an excessive temperature drop of the exhaust due to the refrigerant.

  (10) The invention according to claim 10 is the cooling apparatus for an internal combustion engine according to any one of claims 1 to 9, wherein the exhaust system temperature is lower than the reference temperature and the temperature of the engine body is lower. When the temperature is lower than the main body reference temperature, the refrigerant flow rate in the first refrigerant passage is reduced compared to when the exhaust system temperature is lower than the reference temperature and the engine main body temperature is higher than the main body reference temperature. This is the gist.

  According to the present invention, the flow rate of the refrigerant in the first refrigerant passage is reduced when the temperature of the engine main body is lower than the main body reference temperature, that is, comparison when the engine main body is not sufficiently warmed up. Since the amount of the low-temperature refrigerant supplied to the exhaust device is reduced, it is possible to suppress an excessive temperature drop of the exhaust due to the refrigerant.

  (11) The invention according to claim 11 is the cooling apparatus for an internal combustion engine according to any one of claims 1 to 10, wherein the refrigerant from the refrigerant cooling apparatus passes through the engine main body and the exhaust apparatus. A third refrigerant passage that circulates through the refrigerant cooling device without being interposed, and when the exhaust system temperature is lower than the reference temperature and the engine main body temperature is lower than the main body reference temperature, the exhaust system temperature is The gist is that the flow rate of the refrigerant in the third refrigerant passage is increased as compared with a case where the temperature is lower than the reference temperature and the temperature of the engine main body is higher than the main body reference temperature.

  According to this invention, when the temperature of the engine main body is lower than the main body reference temperature, the flow rate of the refrigerant in the third refrigerant passage is increased, and consequently the flow rates of the refrigerant in the first refrigerant passage and the second refrigerant passage are reduced. Thus, it is possible to suppress an excessive temperature drop of the exhaust due to the refrigerant.

  (12) The invention according to claim 12 is the internal combustion engine cooling apparatus according to claim 11, wherein the exhaust system temperature is lower than the reference temperature and the engine body temperature is lower than the body reference temperature. The gist is that the first refrigerant passage and the second refrigerant passage are closed and the third refrigerant passage is opened.

  According to the present invention, the first refrigerant passage and the second refrigerant passage are closed when the temperature of the engine main body is lower than the main body reference temperature, that is, when the engine main body is not sufficiently warmed up. Since the relatively low-temperature refrigerant is not supplied to the exhaust device, it is possible to suppress an excessive temperature drop of the exhaust gas caused by the refrigerant.

The schematic diagram which shows typically the structure of the engine about one Embodiment which actualized the cooling device of the internal combustion engine of this invention. The table which shows an example of the control mode of each control valve about the cooling device of the internal-combustion engine of the embodiment. The schematic diagram which shows the distribution | circulation aspect of the cooling water of a 1st circulation path about the cooling device of the internal combustion engine of the embodiment. The schematic diagram which shows the distribution | circulation aspect of the cooling water of a 2nd circulation path about the cooling device of the internal combustion engine of the embodiment. The schematic diagram which shows the distribution | circulation aspect of the cooling water of a 3rd circulation path about the cooling device of the internal combustion engine of the embodiment. The flowchart which shows the process sequence about the "cooling apparatus control process" performed by the electronic controller of the embodiment. The timing chart which shows an example of the control aspect about the cooling device of the internal combustion engine of the embodiment. The schematic diagram which shows typically the structure of the engine about other embodiment which actualized the cooling device of the internal combustion engine of this invention.

With reference to FIGS. 1 to 7, an embodiment of the internal combustion engine cooling device of the present invention, which is embodied as a cooling device for cooling an engine body and an exhaust manifold, will be described.
As shown in FIG. 1, an internal combustion engine 1 includes an engine body 10 that burns an air-fuel mixture, an exhaust device 20 that purifies exhaust gas from the engine body 10 and sends it to the outside, and cools the engine body 10 and the exhaust device 20 with cooling water There are provided a cooling device 30 for cooling by means of an electronic control device 60 for controlling these devices.

  The engine body 10 is provided with a cylinder block 11 containing a piston, a cylinder head 12 attached to the upper part of the cylinder block 11, and a water pump 13 driven by a crankshaft to discharge cooling water.

  The exhaust device 20 is provided with an exhaust manifold 21 connected to the exhaust port of the engine body 10 and an exhaust catalyst device 22 connected to the exhaust manifold 21. The exhaust catalyst device 22 is maintained in a sufficiently activated state when the temperature of the catalyst (hereinafter referred to as “catalyst temperature TC”) exceeds the catalyst reference temperature TCX.

  The cooling device 30 includes a radiator 31 that cools the cooling water by heat exchange with the outside air, a thermostat 32 that adjusts the flow rate of the cooling water from the engine body 10 to the radiator 31, and a cooling that cools the exhaust manifold 21 with the cooling water. An adapter 33 is provided. In addition to these, the first control valve 34 for controlling the flow rate of the cooling water flowing from the engine body 10 to the cooling adapter 33, and the flow rate of the cooling water flowing from the radiator 31 to the cooling adapter 33 without passing through the engine body 10 And a second control valve 35 for controlling.

  The cooling water circulation passage 40 includes the following first cooling water passage 41 to seventh cooling water passage 47. The first cooling water passage 41 connects the radiator 31 and the water pump 13 (engine body 10). The second cooling water passage 42 connects the engine body 10 and the inlet port 34 </ b> A of the first control valve 34. The third cooling water passage 43 connects the first outlet port 34 </ b> B of the first control valve 34 and the sixth cooling water passage 46. The fourth cooling water passage 44 connects the second outlet port 34 </ b> C of the first control valve 34 and the cooling adapter 33. The fifth cooling water passage 45 connects the water pump 13 and the fourth cooling water passage 44. The sixth cooling water passage 46 connects the cooling adapter 33 and the radiator 31. The seventh cooling water passage 47 connects the thermostat 32 provided in the middle of the first cooling water passage 41 and the sixth cooling water passage 46.

  In the cooling water circulation passage 40 configured as described above, the communication state between the second cooling water passage 42, the third cooling water passage 43, and the fourth cooling water passage 44 is switched by the first control valve 34. The communication state between the first cooling water passage 41 and the fifth cooling water passage 45 is switched by the second control valve 35. The communication state between the first cooling water passage 41 and the seventh cooling water passage 47 is switched by the thermostat 32. The passage formed by the second cooling water passage 42 and the fourth cooling water passage 44 corresponds to the first refrigerant passage, and is located on the downstream side of the fifth cooling water passage 45 and the junction with the passage. The passage formed by the cooling water passage 44 corresponds to the second refrigerant passage, and the passage formed by the second cooling water passage 42 and the third cooling water passage 43 corresponds to the third refrigerant passage.

  The first control valve 34 is in a state where the inlet port 34A and the first outlet port 34B communicate with each other (fully open), and is closed between the inlet port 34A and the second outlet port 34C (fully closed). The second cooling water passage 42 and the third cooling water passage 43 are communicated with each other, and the second cooling water passage 42 and the fourth cooling water passage 44 are blocked. On the other hand, when the inlet port 34A and the second outlet port 34C are in communication (fully open) and the inlet port 34A and the first outlet port 34B are closed (fully closed), The second cooling water passage 42 and the third cooling water passage 43 are blocked, and the second cooling water passage 42 and the fourth cooling water passage 44 are communicated.

  When the second control valve 35 is in the open state (fully open), the fifth cooling water passage 45 is opened to connect the first cooling water passage 41 and the fifth cooling water passage 45. On the other hand, when the valve is closed (fully closed), the fifth cooling water passage 45 is closed and the first cooling water passage 41 and the fifth cooling water passage 45 are shut off.

  The thermostat 32 passes through the seventh coolant passage 47 and the first coolant when the temperature of the coolant before passing through the engine body 10 and flowing into the radiator 31 is lower than a predetermined temperature (hereinafter, “valve opening temperature TAY”). The flow rate of the cooling water that communicates with the cooling water passage 41 and flows into the radiator 31 is set to “0”. On the other hand, when the temperature of the cooling water before passing through the engine body 10 and flowing into the radiator 31 is higher than the valve opening temperature TAY, the flow rate of the cooling water flowing into the radiator 31 is made larger than “0” and the seventh cooling is performed. The flow rate of the cooling water that passes through the water passage 47 and bypasses the radiator 31 is reduced.

  The electronic controller 60 includes a main body water temperature sensor 61 that outputs a signal corresponding to the temperature of the cooling water flowing in the engine main body 10 (hereinafter, “main body cooling water temperature TA”), and the cooling water flowing in the cooling adapter 33. The exhaust water temperature sensor 62 that outputs a signal corresponding to the temperature (hereinafter referred to as “exhaust cooling water temperature TB”), and the oxygen concentration (hereinafter referred to as “oxygen concentration OC”) of the exhaust near the inlet and the outlet of the exhaust catalyst device 22. Various sensors including the first oxygen sensor 63 and the second oxygen sensor 64 that output a signal corresponding to () are connected. Based on signals input from these sensors, the cooling device 30 is controlled, that is, the first control valve 34 and the second control valve 35 are opened and closed.

Details of the control mode of the cooling device 30 by the electronic control device 60 will be described with reference to FIGS.
The electronic control unit 60 is grasped through the warm-up state of the engine body 10 ascertained through the body cooling water temperature TA, the activation state of the catalyst of the exhaust catalyst device 22 as grasped through the oxygen concentration OC, and the exhaust cooling water temperature TB. Based on the overheated state of the exhaust manifold 21, the open / close state of the first control valve 34 and the second control valve 35 is operated as shown in the following (A) to (C).

  (A) Under the condition that the main body cooling water temperature TA is lower than the valve opening temperature TAY of the thermostat 32, the main body cooling water temperature TA is lower than the main body reference temperature TAX set in advance as a value smaller than the valve opening temperature TAY. When it is small (the left column in FIG. 2), that is, before the engine warm-up is completed and when the main body cooling water temperature TA is low enough to cool the exhaust excessively, the first outlet port 34B of the first control valve 34 is opened. The second outlet port 34C of the first control valve 34 is closed, and the second control valve 35 is closed.

  Accordingly, as shown in FIG. 3, the cooling water circulation passage 40 includes a first cooling water passage 41, a second cooling water passage 42, a third cooling water passage 43, a sixth cooling water passage 46, and a seventh cooling water passage. 47 is formed. Hereinafter, the control mode of the cooling device 30 in which the first circulation passage 51 is formed by the operation of the first control valve 34 and the second control valve 35 is referred to as “engine warm-up mode”.

  When the cooling device 30 is in the engine warm-up mode, the cooling water discharged by the water pump 13 circulates in the cooling water circulation passage 40 through the engine body 10 and the thermostat 32 and without passing through the cooling adapter 33 and the radiator 31. .

  (B) When the main body cooling water temperature TA is higher than the valve opening temperature TAY of the thermostat 32, the catalyst temperature TC is higher than the catalyst reference temperature TCX (center row in FIG. 2), that is, the engine warm-up is completed. After and when the catalyst of the exhaust catalyst device 22 is in a sufficiently activated state, the first outlet port 34B of the first control valve 34 is closed, and the second outlet port 34C of the first control valve 34 is opened, The second control valve 35 is closed.

  As a result, as shown in FIG. 4, the cooling water circulation passage 40 has a second circulation composed of the first cooling water passage 41, the second cooling water passage 42, the fourth cooling water passage 44, and the sixth cooling water passage 46. A passage 52 is formed. Hereinafter, the control mode of the cooling device 30 in which the second circulation passage 52 is formed by the operation of the first control valve 34 and the second control valve 35 is referred to as “catalyst activation mode”.

  When the cooling device 30 is in the catalyst activation mode, the cooling water discharged by the water pump 13 passes through these elements in the order of the engine body 10, the cooling adapter 33, and the radiator 31 and circulates in the cooling water circulation passage 40.

  (C) Under the condition that the main body cooling water temperature TA is higher than the valve opening temperature TAY of the thermostat 32, when the exhaust cooling water temperature TB is higher than the reference temperature TBX (the right column in FIG. 2), When the cooling water flowing through the cooling adapter 33 is overheated after the completion of the machine, the first outlet port 34B of the first control valve 34 is opened, and the second outlet port 34C of the first control valve 34 is closed, The second control valve 35 is opened.

  Accordingly, as shown in FIG. 5, the cooling water circulation passage 40 includes a first cooling water passage 41, a second cooling water passage 42, a third cooling water passage 43, a fifth cooling water passage 45, and a sixth cooling water passage. A third circulation passage 53 formed of 46 is formed. Hereinafter, the control mode of the cooling device 30 in which the third circulation passage 53 is formed by the operation of the first control valve 34 and the second control valve 35 is referred to as “exhaust cooling mode”.

  When the cooling device 30 is in the exhaust cooling mode, the cooling water discharged by the water pump 13 passes through the engine body 10 and does not pass through the cooling adapter 33, and without passing through the engine body 10. In addition, it is divided into a path that passes through the cooling adapter 33 and circulates in the cooling water circulation passage 40.

  With reference to FIG. 6, the content of the “cooling device control process” that defines a specific processing procedure for controlling the cooling device 30 will be described. This process is repeatedly executed at predetermined calculation cycles through the electronic control device 60 when the internal combustion engine 1 is in an operating state.

  (A) When it is determined in step S110 that the exhaust cooling water temperature TB is higher than the reference temperature TBX, that is, when the exhaust manifold 21 may be overheated, the exhaust cooling mode is executed in step S140. The reference temperature TBX is used to determine that the temperature of the exhaust manifold 21 has risen to a point where the possibility of an overheating state of the exhaust manifold 21 is sufficiently high, from the temperature of the cooling water in the cooling adapter 33. It is preset as a value.

  (B) When it is determined in step S110 that the exhaust cooling water temperature TB is equal to or lower than the reference temperature TBX, and in step S120, it is determined that the catalyst temperature TC is higher than the catalyst reference temperature TCX, that is, the exhaust manifold 21 is overheated. When there is no possibility of the state being generated and the exhaust catalyst device 22 is in a sufficiently activated state, the catalyst activation mode is executed in step S150.

  Here, based on the oxygen concentration OC obtained by the first oxygen sensor 63 and the second oxygen sensor 64, whether or not the exhaust catalyst device 22 is sufficiently activated, that is, the catalyst temperature TC is the catalyst reference temperature TCX. It is determined whether or not it is larger than the above. Accordingly, in step S120, it is confirmed that the exhaust catalyst device 22 is in a sufficiently activated state based on the oxygen concentration OC by each sensor, so that the catalyst temperature TC is higher than the catalyst reference temperature TCX. Judgment is made.

  (C) In step S110, it is determined that the exhaust cooling water temperature TB is lower than the reference temperature TBX, in step S120, it is determined that the catalyst temperature TC is lower than the catalyst reference temperature TCX, and in step S130, the main body is cooled. When it is determined that the water temperature TA is equal to or higher than the main body reference temperature TAX, that is, before the engine warm-up is completed, there is no possibility that the exhaust manifold 21 is overheated, and the cooling water that has passed through the engine main body 10 When there is no possibility that the exhaust gas is excessively cooled, the catalyst activation mode is executed in step S150.

  (D) In step S110, it is determined that the exhaust cooling water temperature TB is lower than the reference temperature TBX, in step S120, it is determined that the catalyst temperature TC is lower than the catalyst reference temperature TCX, and in step S130, the main body is cooled. When it is determined that the water temperature TA is lower than the main body reference temperature TAX, that is, before the engine warm-up is completed, there is no possibility that the exhaust manifold 21 is overheated, and the cooling water that has passed through the engine main body 10 When the exhaust may be excessively cooled, the engine warm-up mode is executed in step S160.

With reference to FIG. 7, an example of the control mode of the cooling device 30 by the cooling device control process will be described based on the transition of various parameters.
At time t1, that is, when the operation of the internal combustion engine 1 is started, circulation of the cooling water in the cooling water circulation passage 40 by the water pump 13 is started. Further, based on the fact that “main body cooling water temperature TA <main body reference temperature TAX”, “exhaust cooling water temperature TB ≦ reference temperature TBX”, and “catalyst temperature TC ≦ catalyst reference temperature TCX” are satisfied, The engine warm-up mode is executed as the control mode of the device 30.

  When the condition “main body cooling water temperature TA> main body reference temperature TAX” is satisfied at time t2, that is, due to the temperature rise of the engine main body 10 accompanying the operation of the internal combustion engine 1, “exhaust cooling water temperature TB ≦ reference” The engine warm-up mode is continued as the control mode of the cooling device 30 on the basis that the conditions of “temperature TBX” and “catalyst temperature TC ≦ catalyst reference temperature TCX” are satisfied.

  When the condition “catalyst temperature TC> catalyst reference temperature TCX” is satisfied at time t3, that is, when the temperature of the exhaust catalyst device 22 rises due to the heat received from the exhaust, in addition to the condition, “exhaust cooling water temperature TB ≦ reference temperature TBX” ”Is satisfied, the control mode of the cooling device 30 is switched from the engine warm-up mode to the catalyst activation mode.

  When the condition “main body cooling water temperature TA> valve opening temperature TAY” is satisfied at time t 4, that is, when the temperature of the engine body 10 increases due to the operation of the internal combustion engine 1, the engine body 10 is moved along with the valve opening operation of the thermostat 32. The passing cooling water is discharged by the water pump 13 after passing through the radiator 31.

  When the condition “exhaust cooling water temperature TB> reference temperature TBX” is satisfied at time t5, that is, when the high-load operation of the internal combustion engine 1 is continued, the control mode of the cooling device 30 is determined based on the fact that the condition is satisfied. Is switched from the catalyst activation mode to the exhaust cooling mode. As a result, the cooling water that has passed through the radiator 31 is directly supplied to the cooling adapter 33, so that the exhaust manifold 21 can be rapidly cooled.

  At time t6, that is, when the condition of “exhaust cooling water temperature TB ≦ reference temperature TBX” is satisfied due to the temperature drop of the exhaust manifold 21 due to the execution of the exhaust cooling mode, in addition to the same condition, “catalyst temperature TC> catalyst reference temperature TCX” "Is satisfied, the control mode of the cooling device 30 is switched from the exhaust cooling mode to the catalyst activation mode.

According to the present embodiment, the following effects can be achieved.
(1) In the present embodiment, when the exhaust cooling water temperature TB is higher than the reference temperature TBX, the flow rate of the fifth cooling water passage 45 is increased compared to when the exhaust cooling water temperature TB is lower than the reference temperature TBX. .

  According to this configuration, the flow rate of the fifth cooling water passage 45 is increased when the exhaust cooling water temperature TB is higher than the reference temperature TBX, that is, when the cooling adapter 33 is in a relatively high temperature state, the engine body 10, the flow rate of the cooling water supplied to the cooling adapter 33 without receiving heat increases, so that overheating of the cooling adapter 33 can be suppressed.

  (2) In the present embodiment, when the exhaust cooling water temperature TB is higher than the reference temperature TBX, the flow rate of the fourth cooling water passage 44 is reduced compared to when the exhaust cooling water temperature TB is lower than the reference temperature TBX. .

  According to this configuration, the flow rate of the cooling water in the fourth cooling water passage 44 is reduced when the exhaust cooling water temperature TB is higher than the reference temperature TBX, that is, when the cooling adapter 33 is in a relatively high temperature state. Since the flow rate of the cooling water supplied to the cooling adapter 33 after receiving heat in the engine body 10 is reduced, overheating of the cooling adapter 33 can be more suitably suppressed.

  (3) In the present embodiment, when the exhaust cooling water temperature TB is higher than the reference temperature TBX, the flow rate of the third cooling water passage 43 is increased compared to when the exhaust cooling water temperature TB is lower than the reference temperature TBX. .

  According to this configuration, the flow rate of the third cooling water passage 43 is increased when the exhaust cooling water temperature TB is higher than the reference temperature TBX, that is, the engine main body 10 reaches a place where the cooling adapter 33 becomes relatively high. Since the flow rate of the cooling water that passes through the engine body 10 increases when the temperature of the engine rises, overheating of the cooling adapter 33 and the engine body 10 can be suppressed.

  (4) In the present embodiment, when the cooling adapter 33 is higher than the reference temperature TBX, the fifth cooling water passage 45 and the third cooling water passage 43 are opened, and the fourth cooling water passage 44 is closed.

  According to this configuration, the fifth cooling water passage 45 is closed when the exhaust cooling water temperature TB is higher than the reference temperature TBX, that is, when the cooling adapter 33 is in a relatively high temperature state, the engine body 10 receives heat. After that, the flow rate of the cooling water supplied to the cooling adapter 33 becomes “0”, so that the overheating of the cooling adapter 33 can be more suitably suppressed.

  (5) In the present embodiment, when the exhaust cooling water temperature TB is lower than the reference temperature TBX and the catalyst temperature TC is higher than the catalyst reference temperature TCX, compared to when the exhaust cooling water temperature TB is higher than the reference temperature TBX. The flow rate of the cooling water in the fifth cooling water passage 45 is reduced.

  According to this configuration, when the catalyst temperature TC is higher than the catalyst reference temperature TCX, the flow rate of the cooling water in the fifth cooling water passage 45 is reduced, that is, when the exhaust catalyst device 22 is sufficiently warmed up. In addition, since the flow rate of the cooling water directly supplied from the radiator 31 to the exhaust catalyst device 22 without using the engine body 10 is reduced, the warm-up state of the exhaust catalyst device 22 can be suitably maintained.

  (6) In this embodiment, when the exhaust cooling water temperature TB is lower than the reference temperature TBX and the catalyst temperature TC is higher than the catalyst reference temperature TCX, the exhaust cooling water temperature TB is lower than the reference temperature TBX and the catalyst temperature TC. Compared to when the temperature is lower than the catalyst reference temperature TCX, the flow rate of the fourth cooling water passage 44 is increased.

  According to this configuration, the flow rate of the fourth cooling water passage 44 is increased when the catalyst temperature TC is higher than the catalyst reference temperature TCX, that is, when the exhaust catalyst device 22 is sufficiently warmed up, the engine body 10 Since the flow rate of the cooling water supplied to the exhaust device 20 after receiving heat increases in step 1, the warm-up state of the exhaust catalyst device 22 can be suitably maintained.

  (7) In this embodiment, when the exhaust cooling water temperature TB is lower than the reference temperature TBX and the catalyst temperature TC is higher than the catalyst reference temperature TCX, the exhaust cooling water temperature TB is lower than the reference temperature TBX and the catalyst temperature TC. Compared to when the temperature is lower than the catalyst reference temperature TCX, the flow rate of the third cooling water passage 43 is reduced.

  According to this configuration, since the flow rate of the third cooling water passage 43 is reduced when the catalyst temperature TC is higher than the catalyst reference temperature TCX, that is, when the exhaust catalyst device 22 is sufficiently warmed up, the cooling adapter Since the flow rate of the cooling water supplied to the radiator 31 via 33 is increased, the warm-up state of the exhaust catalyst device 22 can be suitably maintained.

  (8) In the present embodiment, when the exhaust cooling water temperature TB is lower than the reference temperature TBX and the catalyst temperature TC is higher than the catalyst reference temperature TCX, the fifth cooling water passage 45 and the third cooling water passage 43 are closed. In addition, the fourth cooling water passage 44 is opened.

  According to this configuration, when the catalyst temperature TC is higher than the catalyst reference temperature TCX, the cooling adapter 33 is not cooled by the cooling water from the fifth cooling water passage 45, so the exhaust catalyst device 22 is warmed up. Can be suitably maintained.

  (9) In this embodiment, when the exhaust cooling water temperature TB is lower than the reference temperature TBX and the main body cooling water temperature TA is lower than the main body reference temperature TAX, the exhaust cooling water temperature TB is higher than the reference temperature TBX. In comparison, the flow rate of the fifth cooling water passage 45 is reduced.

  According to this configuration, when the main body cooling water temperature TA is lower than the main body reference temperature TAX, the flow rate of the fifth cooling water passage 45 is reduced, that is, the engine main body 10 is not sufficiently warmed up. Since the amount of the relatively low-temperature cooling water supplied to the cooling adapter 33 is reduced, excessive temperature reduction of the exhaust due to the cooling water can be suppressed.

  (10) In this embodiment, when the exhaust cooling water temperature TB is lower than the reference temperature TBX and the main body cooling water temperature TA is lower than the main body reference temperature TAX, the exhaust cooling water temperature TB is lower than the reference temperature TBX and the main body The flow rate of the fourth cooling water passage 44 is reduced compared to when the cooling water temperature TA is higher than the main body reference temperature TAX.

  According to this configuration, when the main body cooling water temperature TA is lower than the main body reference temperature TAX, the flow rate of the fourth cooling water passage 44 is reduced, that is, the engine main body 10 is not sufficiently warmed up. Since the amount of the relatively low-temperature cooling water supplied to the cooling adapter 33 is reduced, excessive temperature reduction of the exhaust due to the cooling water can be suppressed.

  (11) In this embodiment, when the exhaust cooling water temperature TB is lower than the reference temperature TBX and the main body cooling water temperature TA is lower than the main body reference temperature TAX, the exhaust cooling water temperature TB is lower than the reference temperature TBX and the main body The flow rate of the third cooling water passage 43 is increased compared to when the cooling water temperature TA is higher than the main body reference temperature TAX.

  According to this configuration, the flow rate of the third cooling water passage 43 is increased when the main body cooling water temperature TA is lower than the main body reference temperature TAX, and consequently the flow rates of the fourth cooling water passage 44 and the fifth cooling water passage 45 are increased. Since the amount is reduced, an excessive temperature drop of the exhaust due to the cooling water can be suppressed.

  (12) In the present embodiment, when the exhaust cooling water temperature TB is lower than the reference temperature TBX and the main body cooling water temperature TA is lower than the main body reference temperature TAX, the fourth cooling water passage 44 and the fifth cooling water passage 45 are While being closed, the third cooling water passage 43 is opened.

  According to this configuration, since the fourth cooling water passage 44 and the fifth cooling water passage 45 are closed, that is, when the engine body 10 is not sufficiently warmed up, the relatively low-temperature cooling water is cooled. Since it is not supplied to the adapter 33, an excessive temperature drop of the exhaust due to the cooling water can be suppressed.

(Other embodiments)
In addition, the embodiment of the present invention is not limited to the embodiment exemplified in the above-described embodiment, and can be implemented by changing it as shown below, for example.

  In the above embodiment, the first control valve 34 is configured to switch the communication state between the third cooling water passage 43 and the fourth cooling water passage 44. However, instead of the first control valve 34, a broken line frame in FIG. Two control valves (a third control valve 36 and a fourth control valve 37) may be provided as shown in FIG. In this case, the communication state between the third cooling water passage 43 and the sixth cooling water passage 46 is switched by the third control valve 36, and the fourth cooling water passage 44 and the cooling adapter 33 are switched by the fourth control valve 37. The communication state of is switched. According to such a configuration, the arrangement location of the control valve for switching the communication state between the third cooling water passage 43 and the fourth cooling water passage 44 can be set differently from the joining portion of these passages. .

  In this case, the arrangement of the third control valve 36 is set in the middle of the third cooling water passage 43 and around the exhaust manifold 21, so that the flow of the flow path around the engine body 10 and other parts The degree of freedom of arrangement can be increased.

  In the above embodiment, it is determined whether or not the catalyst temperature TC is higher than the catalyst reference temperature TCX (whether or not the exhaust catalyst device 22 is in an active state) based on the oxygen concentration OC of the exhaust. The determination mode for the active state of the exhaust catalyst device 22 is not limited to this. For example, the temperature of the exhaust catalyst device 22 is monitored by a sensor or estimated based on the temperature of the exhaust gas, etc., and the active state of the exhaust catalyst device 22 is determined from the comparison result between the catalyst temperature TC and the catalyst reference temperature TCX obtained thereby. It can also be determined.

  In the above embodiment, it is determined whether there is a possibility that the exhaust manifold 21 is overheated based on the temperature of the cooling water of the cooling adapter 33 (exhaust cooling water temperature TB). The mode of determination can also be changed as follows. That is, the temperature of the exhaust manifold 21 is monitored by a sensor, and the exhaust manifold 21 may be overheated based on the comparison result between the temperature of the manifold and the determination value corresponding to the reference temperature TBX obtained thereby. It can also be determined whether or not.

  In the above embodiment, each of the first control valve 34 and the second control valve 35 is switched to either fully open or fully closed, but the opening of these control valves is opened between fully open and fully closed. It can also be set in degrees. According to this configuration, the cooling adapter 33 can be more suitably cooled by more precisely controlling the flow rates of the cooling water in the third cooling water passage 43 and the fourth cooling water passage 44.

  In the above embodiment, when the exhaust cooling water temperature TB is higher than the reference temperature TBX, the second control valve 35 is maintained fully open. However, the operation mode of the second control valve 35 is limited to this. It is not a thing. In short, the flow rate of the cooling water from the first cooling water passage 41 to the fifth cooling water passage 45 when the exhaust cooling water temperature TB is higher than the reference temperature TBX, and the exhaust cooling water temperature TB is lower than the reference temperature TBX. If the operation mode of the second control valve 35 is larger, the effect according to the effect (1) of the above embodiment can be achieved.

  In the above embodiment, a configuration is adopted in which the second outlet port 34C of the first control valve 34 is kept fully closed when the exhaust cooling water temperature TB is higher than the reference temperature TBX. The embodiment is not limited to this. In short, the flow rate of the cooling water from the second cooling water passage 42 to the fourth cooling water passage 44 when the exhaust cooling water temperature TB is higher than the reference temperature TBX, and the exhaust cooling water temperature TB is lower than the reference temperature TBX. If the operation mode of the first control valve 34 is smaller when compared with the same flow rate, the effect according to the effect (2) of the above embodiment can be achieved.

  In the above embodiment, a configuration is adopted in which the first outlet port 34B of the first control valve 34 is kept fully open when the exhaust cooling water temperature TB is higher than the reference temperature TBX. Is not limited to this. In short, the flow rate of the cooling water from the second cooling water passage 42 to the third cooling water passage 43 when the exhaust cooling water temperature TB is higher than the reference temperature TBX, and the exhaust cooling water temperature TB is lower than the reference temperature TBX. If the operation mode of the first control valve 34 in which the former is larger when compared with the same flow rate, the effect according to the effect (3) of the above embodiment can be achieved.

  In the above embodiment, the second control valve 35 is kept fully closed when the catalyst temperature TC is higher than the catalyst reference temperature TCX. However, the operation mode of the second control valve 35 is limited to this. is not. In short, the flow rate of the cooling water from the first cooling water passage 41 to the fifth cooling water passage 45 when the catalyst temperature TC is higher than the catalyst reference temperature TCX, and when the exhaust cooling water temperature TB is higher than the reference temperature TBX. If the operation mode of the second control valve 35 is smaller when compared with the same flow rate, the effect according to the effect (5) of the above embodiment can be achieved.

  In the above embodiment, a configuration is adopted in which the second outlet port 34C of the first control valve 34 is kept fully open when the catalyst temperature TC is higher than the catalyst reference temperature TCX. However, the operation mode of the first control valve 34 is as follows. It is not limited to this. In short, the flow rate of the cooling water from the second cooling water passage 42 to the fourth cooling water passage 44 when the catalyst temperature TC is higher than the catalyst reference temperature TCX is the same as when the catalyst temperature TC is lower than the catalyst reference temperature TCX. If the operation mode of the first control valve 34 is larger when compared with the flow rate, the effect according to the effect (6) of the above embodiment can be achieved.

  In the above embodiment, the configuration is adopted in which the first outlet port 34B of the first control valve 34 is kept fully closed when the catalyst temperature TC is higher than the catalyst reference temperature TCX. Is not limited to this. In short, the flow rate of the cooling water from the second cooling water passage 42 to the third cooling water passage 43 when the catalyst temperature TC is higher than the catalyst reference temperature TCX and the same when the catalyst temperature TC is lower than the catalyst reference temperature TCX. If the operation mode of the first control valve 34 is smaller when compared with the flow rate, the effect according to the effect (7) of the above embodiment can be achieved.

  In the above embodiment, when the main body cooling water temperature TA is lower than the main body reference temperature TAX, a configuration is adopted in which the second control valve 35 is kept fully closed. However, the operation mode of the second control valve 35 is limited to this. It is not something that can be done. In short, the flow rate of the cooling water from the first cooling water passage 41 to the fifth cooling water passage 45 when the main body cooling water temperature TA is lower than the main body reference temperature TAX, and the exhaust cooling water temperature TB are larger than the reference temperature TBX. If the operation mode of the second control valve 35 is smaller when the same flow rate is compared, an effect according to the effect (9) of the above embodiment can be achieved.

  In the above embodiment, when the main body cooling water temperature TA is lower than the main body reference temperature TAX, the second outlet port 34C of the first control valve 34 is maintained fully closed. The operation mode is not limited to this. In short, the flow rate of the cooling water from the second cooling water passage 42 to the fourth cooling water passage 44 when the main body cooling water temperature TA is lower than the main body reference temperature TAX, and the main body cooling water temperature TA is lower than the main body reference temperature TAX. If the operation mode of the first control valve 34 is smaller when compared with the same flow rate when the flow rate is large, the effect according to the effect (10) of the above embodiment can be achieved.

  In the above embodiment, the configuration is adopted in which the first outlet port 34B of the first control valve 34 is kept fully open when the main body cooling water temperature TA is lower than the main body reference temperature TAX. The embodiment is not limited to this. In short, the flow rate of cooling water from the second cooling water passage 42 to the third cooling water passage 43 when the main body cooling water temperature TA is lower than the main body reference temperature TAX, and the main body cooling water temperature TA is lower than the main body reference temperature TAX. If the operation mode of the first control valve 34 in which the former is larger when compared with the same flow rate when it is larger, the effect according to the effect (11) of the above embodiment can be achieved.

  In the above embodiment, the internal combustion engine 1 including the cooling adapter 33 that cools the exhaust manifold 21 is assumed. However, the internal combustion engine that includes a cooling adapter that cools other parts of the exhaust device 20 (for example, a part of the exhaust pipe). The present invention can also be implemented as a cooling device for an engine.

  In the above-described embodiment, the present invention is applied to the cooling device 30 having a structure in which the exhaust manifold 21 of the exhaust device 20 is cooled by the cooling adapter 33, but is different from the cooling adapter 33 that performs cooling with cooling water in the exhaust device. The present invention can also be applied to a cooling device provided with a device (for example, an EGR device).

  In addition, the configuration of the cooling device including the configuration of the cooling water circulation passage is not limited to the configuration exemplified in the above embodiment, and the cooling water is circulated between the radiator, the engine body, and the exhaust device by the cooling water circulation passage. If it is a cooling device to be used, the present invention can be applied to cooling devices having other configurations in a manner similar to the above embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 10 ... Engine main body, 11 ... Cylinder block, 12 ... Cylinder head, 13 ... Water pump, 20 ... Exhaust device, 21 ... Exhaust manifold, 22 ... Exhaust catalyst device, 23 ... Exhaust pipe, 30 ... Cooling device 31 ... Radiator (refrigerant cooling device), 32 ... Thermostat, 33 ... Cooling adapter, 34 ... First control valve, 34A ... Inlet port, 34B ... First outlet port, 34C ... Second outlet port, 35 ... Second control A valve, 36 ... a third control valve, 37 ... a fourth control valve, 40 ... a cooling water circulation passage (refrigerant passage), 41 ... a first cooling water passage, 42 ... a second cooling water passage, 43 ... a third cooling water passage, 44 ... 4th cooling water passage, 45 ... 5th cooling water passage, 46 ... 6th cooling water passage, 47 ... 7th cooling water passage, 51 ... 1st circulation passage, 52 ... 2nd circulation passage, 53 ... 3rd Circulation path, 60 ... Electronic system Apparatus, 61 ... main body temperature sensor, 62 ... exhaust temperature sensor, 63 ... first oxygen sensor, 64 ... second oxygen sensor.

Claims (12)

In a cooling device for an internal combustion engine that circulates a refrigerant between a refrigerant cooling device and an engine body and an exhaust device by a refrigerant passage,
As the refrigerant passage, a first refrigerant passage through which the refrigerant from the refrigerant cooling device flows to the exhaust device via the engine body, and the refrigerant from the refrigerant cooling device to the exhaust device without passing through the engine body A second refrigerant passage that circulates, and when the temperature of the refrigerant around the exhaust device or the exhaust system temperature, which is the temperature of the exhaust device, is higher than a reference temperature, the exhaust system temperature is higher than the reference temperature. The cooling device for an internal combustion engine, wherein the flow rate of the refrigerant in the second refrigerant passage is increased as compared with when the refrigerant is small. The cooling apparatus for an internal combustion engine according to claim 1,
The internal combustion engine cooling device, wherein the flow rate of the refrigerant in the first refrigerant passage is reduced when the exhaust system temperature is higher than the reference temperature compared to when the exhaust system temperature is lower than the reference temperature. . The cooling device for an internal combustion engine according to claim 1 or 2,
There is further provided a third refrigerant passage through which the refrigerant from the refrigerant cooling device flows to the refrigerant cooling device without passing through the engine body and the exhaust device,
The internal combustion engine cooling device, wherein the flow rate of the refrigerant in the third refrigerant passage is increased when the exhaust system temperature is higher than the reference temperature compared to when the exhaust system temperature is lower than the reference temperature. . The cooling apparatus for an internal combustion engine according to claim 3,
The cooling apparatus for an internal combustion engine, wherein when the exhaust system temperature is higher than the reference temperature, the second refrigerant passage and the third refrigerant passage are opened and the first refrigerant passage is closed. The cooling apparatus for an internal combustion engine according to any one of claims 1 to 4,
The exhaust device includes an exhaust manifold and an exhaust catalyst device,
The cooling device supplies the refrigerant from the refrigerant cooling device to the engine body and the exhaust manifold through the refrigerant passage,
When the exhaust system temperature is lower than the reference temperature and the temperature of the exhaust catalyst device is higher than the catalyst reference temperature, the refrigerant flow rate in the second refrigerant passage is larger than when the exhaust system temperature is higher than the reference temperature. A cooling device for an internal combustion engine, characterized in that the amount is reduced. In the cooling device of the internal combustion engine according to any one of claims 1 to 5,
The exhaust device includes an exhaust manifold and an exhaust catalyst device,
The cooling device supplies the refrigerant from the refrigerant cooling device to the engine body and the exhaust manifold through the refrigerant passage,
When the exhaust system temperature is lower than the reference temperature and the temperature of the exhaust catalyst device is higher than the catalyst reference temperature, the exhaust system temperature is lower than the reference temperature and the temperature of the exhaust catalyst device is higher than the catalyst reference temperature. The cooling device for an internal combustion engine, wherein the flow rate of the refrigerant in the first refrigerant passage is increased as compared with the case where the value is smaller. The internal combustion engine cooling device according to any one of claims 1 to 6,
The exhaust device includes an exhaust manifold and an exhaust catalyst device,
The cooling device supplies the refrigerant from the refrigerant cooling device to the engine main body and the exhaust manifold through the refrigerant passage, and the refrigerant from the refrigerant cooling device passes through the engine main body and not through the exhaust device. A third refrigerant passage that circulates in the refrigerant cooling device;
When the exhaust system temperature is lower than the reference temperature and the temperature of the exhaust catalyst device is higher than the catalyst reference temperature, the exhaust system temperature is lower than the reference temperature and the temperature of the exhaust catalyst device is higher than the catalyst reference temperature. A cooling device for an internal combustion engine, characterized in that the flow rate of the refrigerant in the third refrigerant passage is reduced compared to when the value is smaller. The cooling apparatus for an internal combustion engine according to claim 7,
When the exhaust system temperature is lower than the reference temperature and the temperature of the exhaust catalyst device is higher than the catalyst reference temperature, the second refrigerant passage and the third refrigerant passage are closed and the first refrigerant passage is opened. A cooling device for an internal combustion engine. The internal combustion engine cooling device according to any one of claims 1 to 8,
When the exhaust system temperature is lower than the reference temperature and the engine main body temperature is lower than the main body reference temperature, the refrigerant flow rate in the second refrigerant passage is larger than when the exhaust system temperature is higher than the reference temperature. A cooling device for an internal combustion engine, characterized in that the amount is reduced. The cooling apparatus for an internal combustion engine according to any one of claims 1 to 9,
When the exhaust system temperature is lower than the reference temperature and the engine main body temperature is lower than the main body reference temperature, the exhaust system temperature is lower than the reference temperature and the engine main body temperature is higher than the main body reference temperature. The cooling device for an internal combustion engine, wherein the flow rate of the refrigerant in the first refrigerant passage is reduced as compared with the case. The cooling apparatus for an internal combustion engine according to any one of claims 1 to 10,
There is further provided a third refrigerant passage through which the refrigerant from the refrigerant cooling device flows to the refrigerant cooling device without passing through the engine body and the exhaust device,
When the exhaust system temperature is lower than the reference temperature and the engine main body temperature is lower than the main body reference temperature, the exhaust system temperature is lower than the reference temperature and the engine main body temperature is higher than the main body reference temperature. The cooling device for an internal combustion engine, wherein the flow rate of the refrigerant in the third refrigerant passage is increased as compared with the case. The cooling apparatus for an internal combustion engine according to claim 11,
When the exhaust system temperature is lower than the reference temperature and the temperature of the engine main body is lower than the main body reference temperature, the first refrigerant passage and the second refrigerant passage are closed and the third refrigerant passage is opened. A cooling device for an internal combustion engine, characterized in that:

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