JP2015218604A - Internal combustion engine cooling system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure the heat insulation performance of an internal combustion engine while suppressing an excessive increase of refrigerant temperature and degradation in the performance of an air conditioner after the internal combustion engine stops operating.SOLUTION: An internal combustion engine cooling system (50) comprises: a refrigerant-route switching device (60) capable of switching a state over among a first state, a second state, a third state, and a fourth state, the first state being a state in which refrigerant after passing through an internal combustion engine (10) flows into a heater route (91) and a radiator route (92), the second state being a state in which the refrigerant passing through the internal combustion engine (10) flows into the radiator route (92) without flowing into the heater route (91), the third state being a state in which the refrigerant passing through the internal combustion engine (10) flows into the heater route (91) without flowing into the radiator route (92), and the fourth state being a state in which the refrigerant does not pass through the internal combustion engine (10); and a control unit (80) controlling the refrigerant-route switching device (60) so as to switch the state to the fourth state if a temperature of the refrigerant is lower than a predetermined value after the internal combustion engine (10) stops operating, and so as to switch the state over among the first state, the second state, and the third state in response to an output request of an air conditioner (30) if the temperature of the refrigerant is equal to or higher than the predetermined value after the internal combustion engine (10) stops operating.

Description

  The present invention relates to a cooling device for an internal combustion engine.

  As a conventional cooling device for an internal combustion engine, Patent Document 1 discloses a refrigerant in a predetermined region (referred to as an adiabatic region in Patent Document 1) provided in a refrigerant passage of the internal combustion engine when the operation of the internal combustion engine is stopped. A technique is disclosed in which the temperature of the internal combustion engine is maintained by confinement, thereby suppressing the temperature decrease of the internal combustion engine after the operation of the internal combustion engine is stopped. Patent Document 2 discloses a technology that uses the refrigerant of the internal combustion engine as a heat source of the heater by allowing the refrigerant that has passed through the internal combustion engine to pass through the heater of the air conditioner of the vehicle.

JP 2004-218777 A JP-A-9-195768

  In the technique according to Patent Document 1, when the operation of the internal combustion engine is stopped in a state where the refrigerant temperature of the internal combustion engine is high, the refrigerant may be confined in a predetermined region of the refrigerant passage, and as a result, the refrigerant may overheat. In order to effectively use the refrigerant of the internal combustion engine, the technique according to Patent Document 1 may be applied to a vehicle that uses the refrigerant of the internal combustion engine as a heat source of the heater of the air conditioner as in the technique according to Patent Document 2. Conceivable. However, in this case, the refrigerant is confined in a predetermined region of the refrigerant passage after the operation of the internal combustion engine is stopped, so that it becomes difficult for the refrigerant to pass through the heater. In this case, there is a possibility that the performance of the air conditioner will deteriorate after the operation of the internal combustion engine is stopped.

  An object of the present invention is to provide a cooling device for an internal combustion engine capable of ensuring the heat retaining performance of the internal combustion engine while suppressing the excessive temperature rise of the refrigerant and the performance deterioration of the air conditioner after the operation of the internal combustion engine is stopped.

  The cooling apparatus for an internal combustion engine according to the present invention includes a heater path which is a refrigerant path for allowing a refrigerant to pass through a heater of an air conditioner of a vehicle on which the internal combustion engine is mounted after passing through the internal combustion engine, and the refrigerant is the internal combustion engine A radiator path that is a refrigerant path for passing through the radiator of the vehicle after passing through the vehicle, a first state in which the refrigerant after passing through the internal combustion engine flows into the heater path and the radiator path, and passes through the internal combustion engine A second state in which the subsequent refrigerant flows into the radiator path without flowing into the heater path; and a third state in which the refrigerant after passing through the internal combustion engine flows into the heater path without flowing into the radiator path. A refrigerant path switching device capable of switching between a state and a fourth state in which the refrigerant does not pass through the internal combustion engine, and a temperature of the refrigerant after the operation of the internal combustion engine is stopped. When the temperature is lower than the value, the refrigerant path switching device is controlled so that the fourth state is obtained, and when the temperature of the refrigerant is equal to or higher than the predetermined value after the operation stop, an output request of the air conditioner is obtained. And a control device that controls the refrigerant path switching device so that the first state, the second state, and the third state are switched.

  According to the cooling apparatus for an internal combustion engine according to the present invention, the fourth state is obtained when the temperature of the refrigerant is lower than a predetermined value after the operation of the internal combustion engine is stopped, so that the internal combustion engine can be kept warm. In addition, when the temperature of the refrigerant is equal to or higher than the predetermined value after the operation of the internal combustion engine is stopped, the first state, the second state, and the third state are switched according to the output request of the air conditioner. The path and / or the radiator path can be circulated by natural convection. Thereby, since heat dissipation of a refrigerant | coolant can be accelerated | stimulated, the excessive rise of a refrigerant | coolant can be suppressed. Moreover, since the 1st state, the 2nd state, and the 3rd state are switched according to the output request | requirement of an air conditioner, the performance fall of an air conditioner can also be suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the cooling device of the internal combustion engine which can ensure the thermal insulation performance of an internal combustion engine can be provided, suppressing the excessive temperature rise of a refrigerant | coolant after the operation stop of an internal combustion engine, and the performance fall of an air conditioner.

FIG. 1 is a schematic diagram showing the overall configuration of a vehicle equipped with a cooling device for an internal combustion engine. FIG. 2 is a schematic diagram for explaining details of the operation of the refrigerant path switching device. FIG. 3 is an example of a flowchart showing the control of the refrigerant path switching device of the control device after the operation of the internal combustion engine is stopped. FIG. 4A to FIG. 4G are examples of timing charts after the operation of the internal combustion engine is stopped.

  Hereinafter, modes for carrying out the present invention will be described.

  An internal combustion engine cooling device 50 according to an embodiment of the present invention will be described. The cooling device 50 according to the present embodiment is mounted on the vehicle 5. FIG. 1 is a schematic diagram showing an overall configuration of a vehicle 5 on which a cooling device 50 is mounted. The vehicle 5 includes an internal combustion engine 10, a device 20, an air conditioner 30 that adjusts the temperature inside the vehicle 5, a radiator 40, and a cooling device 50. The device 20 includes an EGR cooler 21 that cools EGR gas, a transmission 22, a transmission cooler 23 that cools oil in the transmission 22, and an oil cooler 24 that cools oil for lubricating the internal combustion engine 10. The air conditioner 30 includes a heater 31 that warms the room and a cooler 32 that cools the room. The transmission 22 according to the present embodiment is specifically an automatic transmission (ATM). However, the configuration of the transmission 22 is not limited to this, and various transmissions such as a manual transmission (MT) can be used.

  The cooling device 50 includes a pump 51, a water jacket 52a formed inside the cylinder block of the internal combustion engine 10, a water jacket 52b formed inside the cylinder head of the internal combustion engine 10, a refrigerant path switching device 60, A temperature sensor 70 and a control device 80 are provided. Further, the cooling device 50 has a plurality of refrigerant paths through which the refrigerant returns to the internal combustion engine 10 after passing through the internal combustion engine 10. As the plurality of refrigerant paths, the cooling device 50 includes a device path 90, a heater path 91, and a radiator path 92. Although the cooling device 50 according to the present embodiment includes the device path 90 as described above, the cooling device 50 does not need to include the device path 90 (that is, the cooling device 50 uses the refrigerant to detach the device 20 from the coolant. Need not be cooled). However, in the case where the cooling device 50 includes the device path 90 as in the present embodiment, the EGR gas, the oil of the transmission 22, and the lubrication of the internal combustion engine 10 are more effective than the case where the cooling path 50 does not include the device path 90. It is preferable at the point which can cool oil effectively.

  The pump 51 is a refrigerant pumping device that pumps the refrigerant to the water jacket 52 a of the internal combustion engine 10. The specific configuration of the pump 51 is not particularly limited, and various water pumps such as a mechanical water pump driven by the power of the crankshaft of the internal combustion engine 10 or an electric water pump driven by a motor may be used. Can be used. In this embodiment, a mechanical water pump is used as an example of the pump 51. The refrigerant pumped from the pump 51 passes through the water jacket 52a and the water jacket 52b in this order, and flows into the refrigerant path switching device 60.

  The device path 90 is used for the refrigerant that has passed through the internal combustion engine 10 to pass through the device 20 (specifically, through the EGR cooler 21, the transmission cooler 23, and the oil cooler 24 in this order) and return to the internal combustion engine 10. It is a refrigerant path. The heater path 91 is a refrigerant path through which the refrigerant that has passed through the internal combustion engine 10 passes through the heater 31 and returns to the internal combustion engine 10. The radiator path 92 is a refrigerant path through which the refrigerant that has passed through the internal combustion engine 10 passes through the radiator 40 and returns to the internal combustion engine 10.

  The refrigerant path switching device 60 is an apparatus that switches the refrigerant flow path in response to an instruction from the control device 80. The refrigerant path switching device 60 according to the present embodiment includes a device port 61 that supplies refrigerant to the device path 90, a heater port 62 that supplies refrigerant to the heater path 91, and a radiator port 63 that supplies refrigerant to the radiator path 92. And a rotary valve (rotary switching valve) capable of switching the open / closed state of these ports is used. Specifically, as an example of the refrigerant path switching device 60, a DC motor-driven multifunction valve is used. More specifically, this valve has a device port 61, a heater port 62, and a radiator port 63 by switching the rotational position of a rotary valve driven by a DC motor that operates in response to an instruction from the control device 80. Switch the open / close state. When the device port 61 is opened, the refrigerant that has passed through the internal combustion engine 10 flows into the device path 90 and passes through the device path 90. When the heater port 62 is opened, the refrigerant that has passed through the internal combustion engine 10 flows into the heater path 91 and passes through the heater path 91. When the radiator port 63 is opened, the refrigerant that has passed through the internal combustion engine 10 flows into the radiator path 92 and passes through the radiator path 92.

  As long as the refrigerant path can be switched as described above, the specific configuration of the refrigerant path switching device 60 is not limited to the rotary valve. As another example, for example, the refrigerant path switching device 60 includes a device valve that opens and closes the device port 61, a heater valve that opens and closes the heater port 62, and a radiator valve that opens and closes the radiator port 63 (that is, A configuration including three types of opening and closing valves may be used. Even in this case, the device port 61 can be opened and closed by opening and closing the device valve, the heater port 62 can be opened and closed by opening and closing the heater valve, and the radiator port 63 can be opened and closed by opening and closing the radiator valve. Can be opened and closed.

  The temperature sensor 70 detects the temperature of the refrigerant and transmits the detection result to the control device 80. The temperature sensor 70 according to the present embodiment detects the temperature of the coolant in the water jacket of the internal combustion engine 10, specifically, the temperature of the coolant in the water jacket 52b formed on the cylinder head. However, the refrigerant temperature detection location by the temperature sensor 70 is not limited to this. The temperature sensor 70 may detect the refrigerant temperature at any point in the cooling device 50. As another example, for example, the temperature sensor 70 may detect the refrigerant temperature at a predetermined location of any one of the device path 90, the heater path 91, and the radiator path 92. Or the temperature sensor 70 may detect the refrigerant | coolant temperature of the several location in the cooling device 50, and may tell the control apparatus 80 what averaged these detection results.

  The control device 80 controls the refrigerant path switching device 60. Further, the control device 80 according to the present embodiment controls the air conditioner 30 in response to the output request of the air conditioner 30. Further, the control device 80 also controls the operation state (for example, fuel injection amount, fuel injection timing, etc.) of the internal combustion engine 10. That is, in the present embodiment, the control device that integrally controls the operation of the vehicle 5 also serves as the control device 80 of the cooling device 50. In the present embodiment, an electronic control unit (Electronic Control Unit) is used as an example of the control device 80. The electronic control device includes a microcomputer having a CPU (Central Processing Unit) 81, a ROM (Read Only Memory) 82, and a RAM (Random Access Memory) 83. The CPU 81 is a device having a function as a control unit that performs various arithmetic processes and control processes. The CPU 81 executes each step of the flowchart described later. The ROM 82 and the RAM 83 are devices having a function as a storage unit that stores information necessary for the operation of the CPU 81.

  FIG. 2 is a schematic diagram for explaining details of the operation of the refrigerant path switching device 60. The refrigerant path switching device 60 has six modes A to F as switching modes of paths through which the refrigerant passes. In the A mode, the device port 61, the heater port 62, and the radiator port 63 are all closed, and as a result, the refrigerant does not pass through any of the device path 90, the heater path 91, and the radiator path 92. In this case, the refrigerant does not pass through the internal combustion engine 10. In the B mode, only the heater port 62 is opened. In this case, the refrigerant that has passed through the internal combustion engine 10 passes only through the heater path 91. In the C mode, the device port 61 and the heater port 62 are opened, and the radiator port 63 is closed. In this case, the refrigerant that has passed through the internal combustion engine 10 passes through the device path 90 and the heater path 91. In the D mode, the device port 61, the heater port 62, and the radiator port 63 are all opened. In this case, the refrigerant that has passed through the internal combustion engine 10 passes through all of the device path 90, the heater path 91, and the radiator path 92.

  In the E mode, only the device port 61 is opened. In this case, the refrigerant that has passed through the internal combustion engine 10 passes only through the device path 90. In the F mode, the device port 61 and the radiator port 63 are opened, and the heater port 62 is closed. In this case, the refrigerant that has passed through the internal combustion engine 10 passes through the device path 90 and the radiator path 92.

  As described above, the refrigerant path switching device 60 according to the present embodiment is a refrigerant path switching device capable of switching the A mode to the F mode. As described above, the refrigerant path switching device 60 according to the present embodiment can switch the six modes A to F, but after the operation of the internal combustion engine 10 is stopped, the A mode, the B mode, and the D mode. And F mode selectively. The operation of the refrigerant path switching device 60 after the operation of the internal combustion engine 10 is stopped will be described in detail with reference to FIG.

  The D mode described above corresponds to a first state in which the refrigerant after passing through the internal combustion engine 10 flows into the heater path 91 and the radiator path 92. The F mode described above corresponds to a second state in which the refrigerant after passing through the internal combustion engine 10 does not flow into the heater path 91 but flows into the radiator path 92. The B mode described above corresponds to a third state in which the refrigerant after passing through the internal combustion engine 10 does not flow into the radiator path 92 but flows into the heater path 91. The A mode described above corresponds to a fourth state in which the refrigerant does not pass through the internal combustion engine 10. The refrigerant path switching device 60 corresponds to a refrigerant path switching device that can switch between the first state, the second state, the third state, and the fourth state. In the present embodiment, since the cooling device 50 has the device path 90 in addition to the heater path 91 and the radiator path 92, the refrigerant after passing through the internal combustion engine 10 in the first state and the second state. Also flows into the device path 90.

  Next, control of the refrigerant path switching device 60 by the control device 80 will be described. The control unit (CPU 81) of the control device 80 controls the refrigerant path switching device 60 so that the A mode (fourth state) is obtained when the temperature of the refrigerant is less than a predetermined value after the operation of the internal combustion engine 10 is stopped. Control. In addition, after the operation of the internal combustion engine 10 is stopped, the control unit responds to an output request of the air conditioner 30 in response to an output request from the air conditioner 30 in the D mode (first state) and the F mode (second mode). State) and B mode (third state) are controlled so that the refrigerant path switching device 60 is switched. The details of this process will be described below with reference to a flowchart.

  FIG. 3 is an example of a flowchart illustrating the control of the refrigerant path switching device 60 of the control device 80 after the operation of the internal combustion engine 10 is stopped (Eng stop). Note that the control unit of the control device 80 supplies fuel to the internal combustion engine 10 when receiving a stop command to stop the operation of the internal combustion engine 10 (specifically, when the ignition switch is turned off). To stop the operation of the internal combustion engine 10. And a control part performs the flowchart of FIG. 3, when the driving | operation of the internal combustion engine 10 stops (specifically, when rotation of the crankshaft of the internal combustion engine 10 stops).

  In step S1, the control unit determines whether or not the refrigerant temperature acquired based on the detection result of the temperature sensor 70 is equal to or higher than a predetermined value stored in advance in the storage unit (ROM 82). Although the specific value of the predetermined value is not particularly limited, in the present embodiment, when the refrigerant is passed through the heater 31, the temperature of the refrigerant considered that the heater 31 can sufficiently exhibit performance. Is used. In other words, even if the refrigerant having a temperature lower than the predetermined value is passed through the heater 31 as the predetermined value in step S1, the heater 31 cannot sufficiently perform the performance, and the refrigerant having a temperature equal to or higher than the predetermined value is not supplied to the heater 31. When the temperature of the refrigerant is passed, the temperature of the refrigerant considered to be able to sufficiently exhibit the performance of the heater 31 is used. In this embodiment, 70 ° C. is used as an example of the predetermined value in step S1. When it determines with No by step S1 (namely, when refrigerant | coolant temperature is less than 70 degreeC), a control part controls the refrigerant | coolant path | route switching apparatus 60 so that A mode (4th state) may be obtained (step S2).

  By performing step S2, cooling of the internal combustion engine 10 by the refrigerant is suppressed, so that the internal combustion engine 10 can be kept warm. Specifically, since the refrigerant does not pass through the internal combustion engine 10 by executing step S2, the refrigerant passes through the internal combustion engine 10 by natural convection after the operation of the internal combustion engine 10 is stopped, and a plurality of refrigerant paths (device paths 90, The cooling of the internal combustion engine 10 can be suppressed and the internal combustion engine 10 can be kept warm as compared with the case of flowing into the heater path 91 and the radiator path 92). As a result, the temperature drop of the internal combustion engine 10 can be effectively suppressed. After step S2, the control unit ends the execution of the flowchart.

  When it is determined Yes in step S1 (that is, when the refrigerant temperature is 70 ° C. or higher), the control unit uses a predetermined time (10 seconds as an example in the present embodiment) from the time when the operation of the internal combustion engine 10 stops. ) It is determined whether the load factor (KL) of the internal combustion engine 10 in the previous state is equal to or greater than a predetermined value (50% is used as an example in the present embodiment) (step S3). Specifically, when there is a command to stop the operation of the internal combustion engine 10, the control unit sequentially acquires the load factor of the internal combustion engine 10 over time and stores it in a storage unit (for example, the RAM 83). In step S3, the control unit acquires from the storage unit the load factor at a time point 10 seconds before the time point when the operation of the internal combustion engine 10 actually stopped (the time point when the rotation of the crankshaft stopped). It is determined whether or not the applied load factor (KL) is 50% or more.

  The load factor of the internal combustion engine 10 refers to the ratio (%) of the actual intake air amount (actual intake air amount) per rotation to the reference maximum intake air amount per rotation of the internal combustion engine 10. It means that the load of the internal combustion engine 10 is larger as the load factor is higher. Therefore, when it is determined Yes in step S3 according to the present embodiment, this corresponds to a case where the operation of the internal combustion engine 10 is stopped in a state where the load of the internal combustion engine 10 is equal to or higher than a predetermined value (that is, a high load state). When it is determined No in S3, it corresponds to a case where the operation of the internal combustion engine 10 is stopped in a state where the load of the internal combustion engine 10 is less than a predetermined value (that is, a low load state).

  When it determines with No by step S3, a control part determines whether there exists an output request | requirement of the heater 31 of the air conditioner 30 (step S4). When it determines with No by step S4, a control part performs step S2 mentioned above. When it determines with Yes by step S4, a control part controls the refrigerant | coolant path | route switching apparatus 60 so that B mode (3rd state) may be acquired (step S5). After step S5, the control unit executes step S4. That is, the control unit maintains the B mode until the output request of the heater 31 is eliminated.

  By executing step S5, the refrigerant that has passed through the internal combustion engine 10 can flow in the heater path 91 by natural convection. Thereby, since the heat dissipation of the refrigerant can be promoted, the excessive temperature rise of the refrigerant after the operation of the internal combustion engine 10 is stopped can be suppressed as compared with, for example, the case where the mode is changed to the A mode in step S5. Further, since the refrigerant can flow through the heater path 91 by natural convection, it is possible to suppress the performance degradation of the air conditioner 30 (specifically, the performance degradation of the heater 31) after the operation of the internal combustion engine 10 is stopped. Further, for example, the heat retention performance of the internal combustion engine 10 can be ensured as compared with the case where the D mode is set in step S5.

  When it determines with Yes by step S3, a control part determines whether there exists an output request | requirement of the cooler 32 of the air conditioner 30 (step S6). When it is determined Yes in step S6 (in this case, the cooler 32 operates and the heater 31 does not operate), the control unit controls the refrigerant path switching device 60 so that the F mode (second state) is obtained. (Step S7).

  By executing step S7, the refrigerant that has passed through the internal combustion engine 10 can flow at least in the radiator path 92 by natural convection without flowing into the heater path 91 (in the present embodiment, By performing step S7, the refrigerant can also flow in the device path 90 by natural convection). Thereby, since the heat release of the refrigerant can be promoted, the excessive temperature rise of the refrigerant after the operation of the internal combustion engine 10 is stopped can be suppressed as compared with, for example, the case where the A mode is set in step S7. Further, since the refrigerant does not flow into the heater path 91 in step S7, it is possible to suppress the deterioration of the air conditioning performance (specifically, the deterioration of the performance of the cooler 32).

  After step S7, the control unit determines whether or not the refrigerant temperature acquired based on the detection result of the temperature sensor 70 is equal to or lower than a predetermined value stored in the storage unit (ROM 82) in advance (step S8). The predetermined value in step S8 is not particularly limited as long as the temperature is higher than the predetermined value in step S1, but in this embodiment, 100 ° C. is used as an example of the predetermined value in step S8. When it determines with No by step S8, a control part performs step S6 mentioned above. When it determines with Yes by step S8, a control part performs step S4 mentioned above.

  When it determines with No by step S6 (namely, when there is no output request of the cooler 32), a control part controls the refrigerant | coolant path | route switching apparatus 60 so that D mode (1st state) may be obtained (step S9). By executing step S9, the refrigerant that has passed through the internal combustion engine 10 can flow by natural convection at least in the heater path 91 and the radiator path 92 (in this embodiment, in step S9, the refrigerant is The device path 90 can also flow by natural convection). Thereby, heat dissipation of the refrigerant can be performed effectively. As a result, it is possible to effectively suppress the excessive temperature rise of the refrigerant after the operation of the internal combustion engine 10 is stopped. After step S9, the control unit executes step S8 described above.

  4A to 4G are examples of timing charts after the operation of the internal combustion engine 10 is stopped. Specifically, FIG. 4A shows an example of a timing chart of the rotational speed of the internal combustion engine 10, FIG. 4B shows an example of a timing chart of the load factor (KL) of the internal combustion engine 10, and FIG. (C) has shown an example of the timing chart of the refrigerant | coolant temperature acquired based on the detection result of the temperature sensor 70. FIG. FIG. 4D shows an example of a timing chart of the air conditioner 30, and FIG. 4E shows an example of a timing chart of the opening degree of the device port 61. FIG. 4F shows an example of a timing chart of the opening degree of the heater port 62, and FIG. 4G shows an example of a timing chart of the opening degree of the radiator port 63. Moreover, the horizontal axis of Fig.4 (a)-FIG.4 (g) is time.

As shown in FIG. 4 (a), the time _{t 1} - time _{t 2,} time _{t 3} ~ Time _{t 4,} at time _{t 5} during the ~ Time _{t 6,} and time _{t 7} after, the rotational speed of the internal combustion engine 10 It is zero and the operation of the internal combustion engine 10 is stopped. When the time _{t 1} ~ time _{t 2,} the coolant temperature, as shown in FIG. 4 (c) is less than 70 ° C.. In this case, the device port 61 shown in FIG. 4 (e) is closed, the heater port 62 shown in FIG. 4 (f) is also closed, and the radiator port 63 shown in FIG. 4 (g) is also closed. Therefore, in this case, the A mode (fourth state) is obtained (corresponding to step S2 in FIG. 3).

For time _{t 3} ~ time _{t 4,} as shown in FIG. 4 (c), the refrigerant temperature is in a 70 ° C. or higher. FIG. 4 (b) as shown in, for 10 seconds before the time _{t 3} the load rate was less than 50%. Further, as shown in FIG. 4D, there is an output request of the heater 31 (heater ON). In this case, only the heater port 62 shown in FIG. 4 (f) is open. Therefore, in this case, the B mode (third state) is obtained (corresponding to step S5 in FIG. 3).

For time _{t 5} ~ time _{t 6,} as shown in FIG. 4 (c), the refrigerant temperature is in a 70 ° C. or higher. Further, as shown in FIG. 4 (b), the load factor of 10 seconds before the time _{t 5} is 50% or more. Further, as shown in FIG. 4D, there is no output request of the cooler 32. In this case, the device port 61 shown in FIG. 4 (e), the heater port 62 shown in FIG. 4 (f), and the radiator port 63 shown in FIG. 4 (g) are all open. Therefore, in this case, the D mode (first state) is obtained (corresponding to step S9 in FIG. 3).

At time t ₇ after, as shown in FIG. 4 (c), the refrigerant temperature is in a 70 ° C. or higher. Further, as shown in FIG. 4 (b), the load factor of 10 seconds before the time _{t 7} is 50% or more. Further, as shown in FIG. 4D, there is an output request of the cooler 32 (cooler ON). In this case, the heater port 62 shown in FIG. 4 (f) is closed, and the device port 61 shown in FIG. 4 (e) and the radiator port 63 shown in FIG. 4 (g) are opened. Therefore, in this case, the F mode (second state) is obtained (corresponding to step S7 in FIG. 3).

  As described above, according to the cooling device 50 according to the present embodiment, the fourth state (step S2) is obtained when the temperature of the refrigerant is lower than the predetermined value after the operation of the internal combustion engine 10 is stopped. The internal combustion engine 10 can be kept warm. Thereby, the temperature fall of the internal combustion engine 10 can be suppressed. Further, when the temperature of the refrigerant is equal to or higher than the predetermined value after the operation of the internal combustion engine 10 is stopped, the first state, the second state, and the third state are switched according to the output request of the air conditioner 30 (step S9). , Step S7, Step S5). Thereby, since heat dissipation of a refrigerant | coolant can be accelerated | stimulated, the excessive rise of a refrigerant | coolant can be suppressed. Moreover, since the 1st state, the 2nd state, and the 3rd state are switched according to the output request | requirement of the air conditioner 30, the performance fall of the air conditioner 30 can also be suppressed.

  Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. It can be changed.

DESCRIPTION OF SYMBOLS 5 Vehicle 10 Internal combustion engine 30 Air conditioning apparatus 50 Cooling apparatus 60 Refrigerant path switching apparatus 80 Control apparatus 90 Device path 91 Heater path 92 Radiator path

Claims (1)

A heater path which is a refrigerant path for passing through a heater of an air conditioner of a vehicle on which the internal combustion engine is mounted after the refrigerant passes through the internal combustion engine;
A radiator path that is a refrigerant path for the refrigerant to pass through the vehicle radiator after passing through the internal combustion engine;
A first state in which the refrigerant after passing through the internal combustion engine flows into the heater path and the radiator path, and a state in which the refrigerant after passing through the internal combustion engine flows into the radiator path without flowing into the heater path. It is possible to switch between two states, a third state in which the refrigerant after passing through the internal combustion engine does not flow into the radiator path but flows into the heater path, and a fourth state in which the refrigerant does not pass through the internal combustion engine. A refrigerant path switching device,
When the temperature of the refrigerant is less than a predetermined value after the operation of the internal combustion engine is stopped, the refrigerant path switching device is controlled so that the fourth state is obtained, and the temperature of the refrigerant after the operation is stopped A control device that controls the refrigerant path switching device so that the first state, the second state, and the third state are switched in response to an output request of the air conditioner when the predetermined value is exceeded; A cooling apparatus for an internal combustion engine.

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