JP2018188973A - Cooling device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device for an internal combustion engine capable of inhibiting boiling of cooling water in a water jacket due to execution of automatic stop in a state where a cooling request is made.SOLUTION: A cooling device includes: a heater cooling water path 52 for supplying cooling water that has passed through a water jacket W of an internal combustion engine 10 to a heater core 18; a second pump 20 provided in the heater cooling water path 52 and driven by an electric motor 20M; and a control valve 16 for opening/closing the heater cooling water path 52. Even when a cooling request is made, if an automatic stop condition of engine operation is satisfied and a temperature of the cooling water that has received heat in the water jacket is a predetermined execution temperature or higher, a cooling control device 100 executes circulation processing for circulating the cooling water in the heater cooling water path 52 by opening the control valve 16 and driving the second pump 20.SELECTED DRAWING: Figure 1

Description

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

  The vehicle has an evaporator that cools the air blown into the passenger compartment, and a heater core that is disposed downstream of the evaporator in the air flow direction and warms the air. An air conditioner that adjusts the temperature according to the cooling requirement is provided.

  Further, for example, in Patent Document 1, as a device for cooling an internal combustion engine that automatically stops engine operation when an automatic stop condition is satisfied, a cooling water passage for a radiator that circulates cooling water between a water jacket and a radiator of the internal combustion engine And a heater cooling water path that circulates the cooling water between the water jacket and the heater core. The cooling device also includes a control valve for opening and closing the heater cooling water passage and the radiator cooling water passage, and a control device for controlling the control valve so that the temperature of the cooling water becomes a target temperature. During the execution of the automatic stop, the control valve is maintained in the state immediately before the automatic stop.

JP 2017-8824 A

  By the way, when the pump provided in the cooling water path for the radiator is a pump whose driving is stopped during the automatic stop of the engine operation, for example, a mechanical pump interlocked with the rotation of the crankshaft of the internal combustion engine. During the automatic stop, the circulation of the cooling water between the water jacket and the radiator is stopped.

  On the other hand, when there is a cooling request, it is desirable to stop the supply of cooling water from the water jacket to the heater core in order to suppress the temperature rise of the air by the heater core. Here, in the case of the above-described conventional technology, if the automatic stop of the internal combustion engine is executed in a state where the state of the control valve is controlled so that the cooling water supply to the heater core is stopped, the automatic stop is performed. The control valve is controlled so that the cooling water supply from the water jacket to the heater core is stopped even during execution. Therefore, when the automatic stop is executed when there is a cooling request, the circulation of the cooling water between the water jacket and the heater core is stopped during the execution of the automatic stop.

  When the automatic stop is executed when there is a cooling request in this manner, the circulation of the cooling water in the radiator cooling water path and the heater cooling water path stops, so that the water jacket cooling water does not circulate. Stay in the jacket. Therefore, in some cases, the water jacket cooling water may be boiled due to the temperature rise due to engine heat.

  A cooling device for an internal combustion engine that solves the above problem is a cooling device for an internal combustion engine that automatically stops engine operation when a predetermined automatic stop condition is satisfied. It is mounted on a vehicle including an air conditioner that adjusts the temperature according to a cooling request. The air conditioner includes an evaporator that cools the air blown into the passenger compartment, and a heater core that is disposed downstream of the evaporator in the air flow direction. The cooling device connects a water jacket provided in the internal combustion engine, a radiator, the water jacket, and the radiator, and circulates cooling water between the water jacket and the radiator. And a first pump that is provided in the cooling water passage for the radiator and stops driving during the automatic stop of the engine operation, the water jacket and the heater core are connected, and the water jacket and the heater core are connected to each other. A cooling water path for the heater for circulating the cooling water, a second pump provided in the cooling water path for the heater and driven by an electric motor, a sensor for detecting the temperature of the cooling water received by the water jacket, A control valve for opening and closing the heater coolant path, driving the second pump, and A control device for controlling the opening and closing of the valve, and a. The control device stops driving the second pump when there is a cooling request, while the cooling water detected by the sensor is satisfied even if the cooling request is satisfied. When the temperature is equal to or higher than a predetermined execution temperature, the control valve is opened and the second pump is driven to execute a circulation process for circulating the cooling water in the heater cooling water path.

  In this configuration, when there is a cooling request, the supply of cooling water from the water jacket to the heater core is stopped by stopping the driving of the second pump provided in the heater cooling water path. Therefore, when there is a cooling request, an increase in air temperature due to the heater core can be suppressed.

  On the other hand, according to this configuration, even if there is a cooling request, if the automatic stop condition is satisfied and the cooling water temperature detected by the sensor is equal to or higher than the predetermined execution temperature, the heater cooling water path The circulation process for circulating the cooling water is performed. Therefore, the cooling water circulates between the water jacket and the heater core without staying in the water jacket. Here, when there is a cooling request, since the heater core is cooled by the air cooled by the evaporator, the cooling water flowing out from the water jacket is cooled when passing through the heater core. Therefore, it is possible to suppress boiling of the water jacket cooling water by executing the automatic stop in a state where there is a cooling request.

  In the above configuration, the first pump that is stopped during automatic stop is a mechanical pump that interlocks with the rotation of the crankshaft of the internal combustion engine, or is controlled so that the drive stops during automatic stop. And an electric pump.

  Further, in one aspect of the cooling device, when the value set to a temperature lower than the execution temperature is set as the stop temperature, the control device detects the cooling water detected by the sensor during the execution of the circulation process. When the temperature becomes equal to or lower than the stop temperature, the driving of the second pump is stopped and the control valve is closed.

  According to the same configuration, when the cooling water temperature detected by the sensor during the above-described circulation process is equal to or lower than the stop temperature, the driving of the second pump provided in the heater cooling water path is stopped. The circulation of the cooling water in the heater cooling water path is stopped. For this reason, it is difficult to supply the warm cooling water of the water jacket to the heater core, and the temperature rise of the air by the heater core can be suppressed. Therefore, the cooling capacity of the air conditioner when there is a cooling request can be increased.

  Here, even if the driving of the second pump provided in the heater coolant path is stopped, if the control valve provided in the heater coolant path is open, the coolant in the heater coolant path is opened. May circulate between the water jacket and the heater core by convection, and in this case, not a little warm cooling water of the water jacket is supplied to the heater core.

  Therefore, in this configuration, the control valve is closed in addition to stopping the driving of the second pump. Therefore, the convection of the cooling water in the heater cooling water path can be suppressed, and this further suppresses the supply of warm cooling water in the water jacket to the heater core, thereby further improving the cooling capacity of the air conditioner. Can be increased.

  Further, in one aspect of the cooling device, when the value set to a temperature lower than the execution temperature is set as the stop temperature, the control device detects the cooling water detected by the sensor during the execution of the circulation process. When the temperature of the second pump becomes equal to or lower than the stop temperature, the driving of the second pump is stopped while maintaining the open state of the control valve.

  According to the same configuration, when the cooling water temperature detected by the sensor during the above-described circulation process is equal to or lower than the stop temperature, the driving of the second pump provided in the heater cooling water path is stopped. The circulation of the cooling water in the heater cooling water path is stopped. For this reason, it is difficult to supply the warm cooling water of the water jacket to the heater core, and the temperature rise of the air by the heater core can be suppressed. Therefore, the cooling capacity of the air conditioner when there is a cooling request can be increased.

  Further, in this configuration, although the drive of the second pump stops, the control valve is maintained in its open state, so that it is possible to suppress the generation of operation noise when closing the open control valve. Can do.

  On the other hand, as described above, when the cooling water temperature detected by the sensor during the circulation process becomes equal to or lower than the stop temperature, the cooling water temperature exceeds the stop temperature when the driving of the second pump is stopped. If the running time becomes excessively long, the continuous driving time of the second pump also becomes long, so that there is a possibility that seizure occurs in the electric motor that drives the second pump.

  Therefore, in one aspect of the cooling device, the control device uses the sensor during execution of the circulation process when the driving time of the second pump after the circulation process is started is equal to or greater than a predetermined threshold. Even if the detected temperature of the cooling water exceeds the stop temperature, the driving of the second pump may be stopped.

  According to the configuration, when the driving time of the second pump becomes equal to or longer than the threshold value, the driving of the second pump is stopped, so that the electric motor driving the second pump can be prevented from being burned.

The schematic diagram which shows the structure of the cooling system of a vehicle and air-conditioner to which one Embodiment of the cooling device of an internal combustion engine is applied. The graph which shows the relationship between the valve phase of the control valve with which the cooling device of the embodiment is provided, and the opening ratio of each port. 6 is a flowchart showing a processing procedure for setting a circulation processing execution flag in the embodiment. The flowchart which shows a series of processing procedures regarding implementation of a circulation process in the embodiment. The flowchart which shows a part of process sequence in the case of implementing a circulation process in the modification of the embodiment.

  Hereinafter, an embodiment of a cooling device for an internal combustion engine will be described with reference to FIGS. In addition, the cooling device of this embodiment is applied to the internal combustion engine of the vehicle 1 provided with the air conditioner which adjusts the temperature of the air blown into the vehicle interior.

  As shown in FIG. 1, the cylinder block 11 of the internal combustion engine 10 is provided with a block-side water jacket 14 through which cooling water flows, and the cylinder head 12 of the internal combustion engine 10 has passed through the block-side water jacket 14. A head-side water jacket 15 through which cooling water flows is provided. Hereinafter, both the block-side water jacket 14 and the head-side water jacket 15 are collectively referred to as a water jacket W.

  A drill path 14 </ b> A that connects the block-side water jacket 14 and the head-side water jacket 15 is provided between bores located between adjacent cylinders in the cylinder block 11. A part of the cooling water introduced into the block-side water jacket 14 flows into the head-side water jacket 15 through the drill path 14A. The cooling between the bores is performed by introducing the cooling water into the drill path 14A.

The head-side water jacket 15 is formed with an exhaust port water jacket 15A for cooling the exhaust port provided in the cylinder head 12 with cooling water.
A first pump 13 is connected to the inlet of the block-side water jacket 14. The first pump 13 is a mechanical pump that interlocks with the rotation of the crankshaft of the internal combustion engine 10. Cooling water discharged from the first pump 13 is introduced into the block-side water jacket 14.

A control valve 16 is connected to the outlet of the head-side water jacket 15 to switch the cooling water circulation path and adjust the flow rate of the cooling water flowing through the circulation path.
The control valve 16 is provided with three ports, a radiator port P1, a heater port P2, and a device port P3, as discharge ports serving as cooling water discharge ports.

  The radiator port P1 is connected to a radiator cooling water path 51 provided with a radiator 17 for cooling the cooling water through heat exchange with the outside air. In addition, the heater port P2 is provided with a heater coolant path 52 in which a heater core 18 that warms air blown into the vehicle compartment by heat exchange with the coolant and a second pump 20 that is driven by the electric motor 20M are provided in the middle. Is connected. The device port P3 is connected to a device coolant passage 53 in which another device 19 (for example, an EGR valve, an EGR cooler, an oil cooler, an ATF warmer, etc.) different from the heater core 18 is provided.

  The downstream end of the radiator coolant path 51 is connected to the suction port of the first pump 13. Therefore, the radiator cooling water path 51 is a path through which the cooling water that has passed through the water jacket W returns to the first pump 13 via the radiator port P <b> 1 of the control valve 16 and the radiator 17. That is, the radiator cooling water path 51 is a cooling water path that connects the water jacket W and the radiator 17 and circulates the cooling water between the water jacket W and the radiator 17.

  Further, the downstream end of the heater cooling water passage 52 is connected to a portion of the radiator cooling water passage 51 between the radiator 17 and the first pump 13. Therefore, the heater cooling water path 52 is a path through which the cooling water that has passed through the water jacket W returns to the first pump 13 via the heater port P2, the heater core 18, and the second pump 20 of the control valve 16. . That is, the heater cooling water path 52 is a cooling water path that connects the water jacket W and the heater core 18 and circulates the cooling water between the water jacket W and the heater core 18.

  The downstream end of the device cooling water passage 53 is connected to a portion of the heater cooling water passage 52 downstream of the second pump 20. Therefore, the cooling water path 53 for devices is a path through which the cooling water that has passed through the water jacket W returns to the first pump 13 via the device port P3 and the device 19 of the control valve 16. That is, the device cooling water path 53 is a cooling water path that connects the water jacket W and the device 19 and circulates the cooling water between the water jacket W and the device 19.

  A valve body that is rotated by an electric motor is provided inside the control valve 16. And the opening rate of said three discharge ports P1-P3 with which the control valve 16 is provided changes with the operation position (henceforth, valve phase (theta)) of the valve body. Note that the opening ratio represents the ratio of the opening area when the opening area at the full opening of each of the discharge ports P1 to P3 is “100%”.

  FIG. 2 shows the relationship between the valve phase θ of the control valve 16 and the respective opening ratios of the radiator port P1, the heater port P2, and the device port P3. The valve phase θ represents the rotation angle of the valve body in the plus or minus direction from the position where the valve phase is “0 °” at the position where all the discharge ports P1 to P3 are fully closed. Yes. Here, the plus direction refers to the rotation direction of the valve body in the direction in which the valve phase θ changes on the right side of the graph on the horizontal axis of FIG. 2, and the minus direction refers to the valve phase θ on the left side in the drawing. Refers to the direction of rotation of the valve body in the direction in which.

  As shown in FIG. 2, the opening ratios of the discharge ports P1 to P3 are set so as to change depending on the valve phase θ of the valve body. The range of the valve phase θ on the plus side of “0 °” is the range of the valve phase θ that is mainly used when the outside air temperature is low and there is a high possibility that heating is used in the passenger compartment. “Winter mode use area”. This “winter mode use area” is used when heating the vehicle interior. Also, the range of the valve phase θ on the minus side from “0 °” is the range of the valve phase θ that is mainly used when the outside air temperature is high and the possibility of cooling being used in the passenger compartment is high. "Summer mode use range". When the cooling is requested, the “summer mode use area” is used.

  When the valve body is rotated in the plus direction from the position where the valve phase θ is “0 °”, the heater port P2 starts to open first, and the opening ratio of the heater port P2 gradually increases as the valve phase θ increases in the plus direction. Become. When the heater port P2 is fully opened, that is, when the opening ratio reaches “100%”, the device port P3 starts to open next, and the opening ratio of the device port P3 gradually increases as the valve phase θ increases in the positive direction. Become. When the device port P3 is fully opened, that is, when the opening ratio reaches “100%”, the radiator port P1 starts to open, and the opening ratio of the radiator port P1 gradually increases as the valve phase θ increases in the positive direction. Eventually, the radiator port P1 is fully opened, that is, its aperture ratio reaches “100%”.

  On the other hand, when the valve body is rotated in the minus direction from the position where the valve phase θ is “0 °”, the device port P3 starts to open first, and the opening ratio of the device port P3 increases according to the increase of the valve phase θ in the minus direction. It grows gradually. Then, the radiator port P1 starts to open from the position where the device port P3 reaches the fully open position, that is, the position where the opening ratio reaches “100%”, and in response to the increase of the valve phase θ in the minus direction. The opening ratio of the radiator port P1 gradually increases, and finally, the radiator port P1 is fully opened, that is, the opening ratio reaches “100%”.

In the region where the valve phase θ is on the minus side of the “0 °” position, the heater port P2 is always fully closed.
As shown in FIG. 1, the air conditioner 70 includes an air conditioning passage 71 for guiding air into the passenger compartment. The air conditioning passage 71 has a blower 76, in order toward the downstream in the air flow direction. An evaporator 72 and the heater core 18 are provided.

  The blower 76 is a device that blows air whose temperature is adjusted from a blower opening 78 provided in the air conditioning passage 71 toward the vehicle interior. The evaporator 72 is a device that cools the air blown into the vehicle interior. The heater core 18 is a device that warms the air blown into the passenger compartment.

  A compressor 75 that compresses and liquefies the refrigerant that has passed through the evaporator 72 is connected to the refrigerant outlet of the evaporator 72. The compressor 75 is connected to an air conditioning control device 300 that controls the refrigerant compression operation and the stop of the compression operation by the compressor 75. An operation panel 310 for a passenger of the vehicle 1 to operate the air conditioner 70 is provided in the passenger compartment, and an air conditioning request (cooling request or heating request) according to the operation state of the operation panel 310 is used for air conditioning. Input to the controller 300. For example, when there is a cooling request, the refrigerant passing through the evaporator 72 is cooled by the refrigerant 75 being compressed by the compressor 75.

  The refrigerant compressed by the compressor 75 is sent to the condenser 74 to be cooled, whereby liquefaction is further advanced. The refrigerant sent to the condenser 74 is liquefied when passing through the expansion valve 73 and sent again into the evaporator 72, and the evaporator 72 is cooled by the heat of vaporization, so that the air passing through the evaporator 72 is changed. To be cooled.

  The heater core 18 is provided with an air mix door 77 that adjusts the amount of air passing through the heater core 18. The temperature of the air blown into the vehicle interior is adjusted by adjusting the amount of air passing through the heater core 18 among the air cooled by the evaporator 72 through the opening adjustment of the air mix door 77.

  A control device for a cooling device that controls the driving of the control valve 16 and the second pump 20 (hereinafter referred to as “cooling control device 100”) includes a central processing unit that performs various calculations related to cooling control of the internal combustion engine 10, The computer unit includes a memory for storing a control program and data. The cooling control device 100 detects the temperature of the cooling water received by the water jacket W, more specifically, the temperature of the cooling water just before flowing out from the head side water jacket 15 (hereinafter referred to as the cooling water temperature THWE). Detection signals from the water temperature sensor 240 and the valve phase sensor 250 that detects the valve phase θ of the control valve 16 are input.

  The engine control device 200 is configured as a computer unit that includes a central processing unit that performs various calculations related to operation control of the internal combustion engine 10 and a memory that stores a control program and data. The engine control device 200 includes various information relating to the operating state of the internal combustion engine 10 and the vehicle 1, for example, a signal of the crank angle sensor 210 for detecting the engine rotational speed NE, and an accelerator sensor 220 for detecting the operating state of the accelerator pedal. And a signal from the vehicle speed sensor 230 that detects the vehicle speed SP of the vehicle 1 are input. Further, the engine control device 200 acquires an air conditioning request from the air conditioning control device 300. This engine control apparatus 200 is one of operation controls, and automatically stops the operation of the internal combustion engine 10 when a predetermined automatic stop condition is satisfied, and restarts the internal combustion engine 10 when a predetermined automatic start condition is satisfied. The automatic stop and automatic start control are executed.

Then, the cooling control device 100 acquires information about whether or not the above-described automatic stop condition is satisfied from the engine control device 200.
The cooling control device 100 performs the following water temperature control in order to set the cooling water temperature to the target water temperature set based on the engine operating state through the adjustment of the valve phase θ of the control valve 16.

  The cooling control device 100 that executes this water temperature control is based on the deviation between the cooling water temperature THWE detected by the water temperature sensor 240 and the target water temperature, and the control valve 16 necessary for setting the cooling water temperature THWE to the target water temperature. The valve phase θ is set as the required valve phase.

  The requested valve phase is set to the valve phase θ within the range A shown in FIG. 2 when there is no heating request to the air conditioner 70. In the range A, the heater port P2 is maintained in the fully closed state and the device port P3 is maintained in the fully open state with respect to the change of the valve phase θ, while only the opening ratio of the radiator port P1 changes. It is the range. When there is a heating request, the valve phase θ is set within the range B shown in FIG. The range B is a range of the valve phase θ in which only the opening ratio of the radiator port P1 changes while the heater port P2 and the device port P3 are both kept fully open with respect to the change in the valve phase θ. When the cooling water temperature THWE is higher than the target water temperature, the cooling control device 100 sets the required valve phase so that the opening ratio of the radiator port P1 is larger than the current state, and the cooling water temperature THWE is lower than the target water temperature. Sometimes, the required valve phase is set so that the opening ratio of the radiator port P1 is larger than the current state. Then, the cooling control device 100 performs drive control of the control valve 16 so that the actual valve phase detected by the valve phase sensor 250 becomes the required valve phase.

  In addition, when there is a heating request, the cooling control device 100 causes the electric motor 20M to increase the discharge amount of the second pump 20 as the target temperature of the air blown from the air outlet 78 toward the vehicle interior is higher. By variably setting the rotational speed, the temperature rise amount of the air warmed by the heater core 18 is increased. As described above, when there is a cooling request, the heater port P2 is fully closed by using the “summer mode use area”. Further, when there is a cooling request, the cooling control device 100 stops driving the second pump 20. When there is a cooling request through the fully closing of the heater port P2 and the driving stop of the second pump 20, the cooling water supply from the water jacket W to the heater core 18 is stopped. Therefore, when there is a cooling request, an increase in the temperature of the air by the heater core 18 can be suppressed.

  By the way, when cooling is requested, the heater port P2 is fully closed and the driving of the second pump 20 is stopped, so that the circulation of the cooling water between the water jacket W and the heater core 18 is stopped. Here, since the first pump 13 is driven during engine operation, the cooling water circulates between the water jacket W and the radiator 17. On the other hand, when the automatic stop of the internal combustion engine 10 is executed, the first pump 13 stops driving, so that the cooling water circulation between the water jacket W and the radiator 17 is also stopped.

  In such a situation where the cooling request overlaps with the automatic engine stop, the cooling water circulation stops in both the radiator cooling water path 51 and the heater cooling water path 52, and therefore the cooling water in the water jacket W circulates. Stay in the water jacket W without any problems. Therefore, in some cases, the cooling water of the water jacket W may be boiled by being heated by the engine heat. In the internal combustion engine 10 of the present embodiment, the cooling water in the exhaust port water jacket 15A for cooling the exhaust port and the cooling water in the drill path 14A for cooling between the bores are particularly easily boiled. .

  Therefore, in order to suppress the boiling of the cooling water in the water jacket W, the cooling control device 100 according to the present embodiment satisfies the conditions described later in a situation where the cooling request and the automatic engine stop overlap, and the cooling water for heater A circulation process for circulating the cooling water in the path 52 is executed.

Hereinafter, various processing procedures relating to such circulation processing will be described.
FIG. 3 shows a processing procedure for setting the cyclic processing execution flag F. This process is repeatedly executed by the cooling control device 100 at predetermined intervals.

  When this process is started, the cooling control device 100 determines whether or not there is a cooling request (S100). And when there exists a cooling request | requirement (S100: YES), it is determined whether the automatic stop conditions of the internal combustion engine 10 are satisfied (S110). When the automatic stop condition is satisfied (S110: YES), the cooling control device 100 determines whether or not the coolant temperature THWE is equal to or higher than a predetermined execution temperature α (S120). The effective temperature α is based on the fact that the cooling water temperature THWE is higher than the effective temperature α, and the current temperature of the cooling water in the water jacket W is a circulation that suppresses boiling of the cooling water in the water jacket W. The size of the value is set so that it can be accurately determined that the necessity of processing is high to some extent.

  When the cooling water temperature THWE is lower than the execution temperature α (S120: NO), the cooling control device 100 once ends this process. On the other hand, when the coolant temperature THWE is equal to or higher than the execution temperature α (S120: YES), the cooling control device 100 sets the circulation process execution flag F to “1” (S130), and ends this process once. .

  On the other hand, when it is determined in step S100 that there is no cooling request (S100: NO), or when it is determined in step S110 that the automatic stop condition is not satisfied (S110: NO), the cooling control device 100 is selected. Sets the circulation process execution flag F to “0” (S140), and terminates this process once.

FIG. 4 shows a series of processing procedures for executing the circulation processing. This process is also repeatedly executed at predetermined intervals by the cooling control device 100.
When this processing is started, the cooling control device 100 determines whether or not the circulation processing execution flag is “1” (S200). When the circulation processing execution flag is “1” (S200: YES), the cooling control device 100 adjusts the valve phase θ of the control valve 16 so that the heater port P2 of the control valve 16 is opened and By driving the pump 20, the above-described circulation process is executed (S210). In this embodiment, the valve phase θ of the control valve 16 is controlled so that the opening rate of the heater port P2 during the circulation process executed in step S210 is “100%”. The aperture ratio of the heater port P2 during execution may be changed as appropriate. Further, while the circulation process is being executed, the rotation speed of the electric motor 20M is controlled so that the discharge amount of the second pump 20 becomes the maximum discharge amount, but such a discharge amount may be changed as appropriate.

  Next, the cooling control device 100 determines whether or not the coolant temperature THWE is equal to or lower than the stop temperature β (S220). In the present embodiment, a temperature slightly lower than the execution temperature α is set as the stop temperature β.

  When the cooling water temperature THWE is equal to or lower than the stop temperature β (S220: YES), the cooling control device 100 adjusts the valve phase θ of the control valve 16 so that the heater port P2 of the control valve 16 is closed. The circulation processing is stopped by stopping the driving of the two pumps 20 (S230). Then, the cooling control device 100 sets the circulation process execution flag F to “0” (S240), and once ends this process.

  When it is determined in step S220 that the cooling water temperature THWE exceeds the stop temperature β (S220: NO), the cooling control device 100 determines the second pump 20 after the current circulation process is started. It is determined whether or not the drive time (continuous drive time) is equal to or greater than a threshold value γ (S250). As this threshold value γ, based on the fact that the driving time of the second pump 20 is longer than the threshold value γ, the electric motor 20M is stopped so that the electric motor 20M that drives the second pump 20 does not burn. The magnitude of the value is set so that it can be accurately determined that the driving time of the second pump 20 has become long enough.

And when the drive time (continuous drive time) of the 2nd pump 20 is less than threshold value (gamma) (S250: NO), the control apparatus 100 for cooling once complete | finishes this process.
On the other hand, when the drive time (continuous drive time) of the second pump 20 is greater than or equal to the threshold value γ (S250: YES), the cooling control device 100 executes the processes of step S230 and step S240, and then The process is temporarily terminated.

  When it is determined in step S200 that the circulation process execution flag is not “1” (S200: NO), the cooling control device 100 executes the processes in steps S230 and S240, and then The process is temporarily terminated.

According to this embodiment described above, the following effects can be obtained.
(1) As shown in FIG. 3 above, even if there is a cooling request (S100: YES), the automatic stop condition is satisfied (S110: YES), and the cooling water temperature THWE is equal to the execution temperature α. If this is the case (S120: YES), the circulation process execution flag F is set to “1” (S130). As shown in FIG. 4, when the circulation process execution flag F is set to “1” (S200: YES), the circulation process for circulating the cooling water in the heater cooling water path 52 is performed. Is executed (S210). Therefore, the cooling water circulates between the water jacket W and the heater core 18 without staying in the water jacket W of the internal combustion engine 10.

  Here, when there is a cooling request, the heater core 18 is cooled by the air cooled by the evaporator 72, so that the cooling water flowing out of the water jacket W is cooled when passing through the heater core 18. Therefore, when the internal combustion engine 10 is automatically stopped in a state where there is a cooling request, it is possible to suppress boiling of the cooling water in the water jacket W.

  (2) When the coolant temperature THWE during the circulation process is equal to or lower than the stop temperature β (S220: YES in FIG. 4), the heater port P2 of the control valve 16 is closed and the driving of the second pump 20 is stopped. Thus, the circulation process is stopped (S230 in FIG. 4). Therefore, the warm cooling water of the water jacket W is not supplied to the heater core 18, and the temperature rise of the air by the heater core 18 is suppressed. Therefore, the cooling capacity of the air conditioner 70 when there is a cooling request can be increased.

  Here, if the driving of the second pump 20 is stopped without closing the heater port P2, the cooling water in the heater cooling water path 52 may circulate between the water jacket W and the heater core 18 by convection. In this case, the warm cooling water of the water jacket W is supplied to the heater core 18 not a little.

  In this regard, in the present embodiment, when the circulation process is stopped as described above, the heater port P2 is closed and the driving of the second pump 20 is stopped. Therefore, the convection of the cooling water in the heater cooling water passage 52 can be suppressed, and thereby the supply of the warm cooling water of the water jacket W to the heater core 18 can be further suppressed. The cooling capacity can be further increased.

  (3) In the present embodiment, as described above, when the coolant temperature THWE becomes equal to or lower than the stop temperature β during the execution of the circulation process, the driving of the second pump 20 is stopped. However, if the time during which the coolant temperature THWE exceeds the stop temperature β becomes excessively long, the continuous drive time of the second pump 20 also becomes long, and the electric motor 20M that drives the second pump 20 may be seized. is there.

  Therefore, in the present embodiment, even when the coolant temperature THWE during the circulation process exceeds the stop temperature β (S220: NO in FIG. 4), when the driving time of the second pump 20 is equal to or greater than the threshold γ (FIG. 4 S250: YES), the driving of the second pump 20 is stopped (S230 in FIG. 4). Therefore, the burn-in of the electric motor 20M can be suppressed.

In addition, the said embodiment can also be changed and implemented as follows.
In the above embodiment, when the circulation process is stopped in step S230 shown in FIG. 4, the heater port P2 is closed and the driving of the second pump 20 is stopped. In addition, instead of the process in step S230 shown in FIG. 4, the process in step S300 shown in FIG. 5 may be performed. That is, when the circulation process is stopped, the driving of the second pump 20 may be stopped while the valve opening state of the heater port P2 is maintained.

  Also in this modified example, when the cooling water temperature THWE becomes equal to or lower than the stop temperature β during the above-described circulation process (S220: YES), the driving of the second pump 20 provided in the heater cooling water path 52 is stopped. Therefore, the circulation of the cooling water in the heater cooling water path 52 is stopped. Therefore, the warm cooling water of the water jacket W becomes difficult to be supplied to the heater core 18, and the temperature rise of the air by the heater core 18 is suppressed. Therefore, the cooling capacity of the air conditioner 70 when there is a cooling request can be increased.

  On the other hand, when the opened heater port P2 is closed, an operation sound is generated from the control valve 16. In this modification, when the circulation process is stopped, the driving of the second pump 20 is stopped. However, the heater port P2 of the control valve 16 is kept open. Therefore, it is possible to suppress the generation of operation noise from the control valve 16 when the circulation process is stopped.

  Each process of step S250 and step S260 shown in FIG. 4 is omitted. When a negative determination is made in step S220, the series of processes shown in FIG. 4 may be temporarily terminated, and the processes after step S220 may be executed again in the next execution cycle. Even in this case, the effects described in the above (1) and (2) can be obtained.

  The opening / closing of the cooling water passage 51 for the radiator, the opening / closing of the cooling water passage 52 for the heater, and the opening / closing of the cooling water passage 53 for the device are performed by one control valve 16. In addition, a control valve for opening and closing the cooling water path may be provided in each of the radiator cooling water path 51, the heater cooling water path 52, and the device cooling water path 53.

The device 19 and the device cooling water path 53 may be omitted.
In order to detect the temperature of the cooling water received by the water jacket W, the temperature of the cooling water just before flowing out from the head side water jacket 15 is detected by the water temperature sensor 240, but the cooling water temperature of other parts May be detected. For example, the temperature of the cooling water immediately after flowing out of the head-side water jacket 15 may be detected by the water temperature sensor 240.

  The first pump 13 was a mechanical pump that interlocks with the rotation of the crankshaft of the internal combustion engine 10. In addition, as the first pump 13, an electric pump that is controlled to stop driving while the internal combustion engine 10 is automatically stopped may be employed.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 10 ... Internal combustion engine, 11 ... Cylinder block, 12 ... Cylinder head, 13 ... 1st pump, 14 ... Block side water jacket, 14A ... Drill path, 15 ... Head side water jacket, 15A ... Water jacket for exhaust port , 16 ... Control valve, 17 ... Radiator, 18 ... Heater core, 19 ... Device, 20 ... Second pump, 20M ... Electric motor, 51 ... Radiator cooling water path, 52 ... Heater cooling water path, 53 ... Device cooling Water path, 70 ... Air conditioner, 71 ... Air conditioning passage, 72 ... Evaporator, 73 ... Expansion valve, 74 ... Condenser, 75 ... Compressor, 76 ... Blower, 77 ... Air mix door, 78 ... Air outlet, 100 ... For cooling Control device 200 ... Engine control device 210 ... Crank angle sensor 220 ... Accelerator sensor 230 ... Car Sensor, 240 ... temperature sensor, 250 ... valve phase sensor, 300 ... control unit for air-conditioning, 310 ... control panel, W ... water jacket, P1 ... radiator port, P2 ... heater port, P3 ... device port.

Claims (4)

A cooling device for an internal combustion engine in which engine operation is automatically stopped when a predetermined automatic stop condition is satisfied,
The internal combustion engine is mounted on a vehicle including an air conditioner that adjusts the temperature of air blown into the vehicle interior according to a cooling request,
The air conditioner includes an evaporator that cools air that is blown into a vehicle interior, and a heater core that is disposed downstream of the evaporator in the air flow direction,
The cooling device is
A water jacket provided in the internal combustion engine;
A radiator cooling water path for connecting a radiator, the water jacket and the radiator, and circulating cooling water between the water jacket and the radiator;
A first pump that is provided in the radiator cooling water path and stops driving during the automatic stop of the engine operation;
A cooling water path for the heater that connects the water jacket and the heater core and circulates the cooling water between the water jacket and the heater core;
A second pump provided in the heater coolant path and driven by an electric motor;
A sensor for detecting the temperature of the cooling water received by the water jacket;
A control valve for opening and closing the heater coolant path;
A control device for controlling the drive of the second pump and the opening and closing of the control valve,
The control device includes:
While there is a cooling request, the driving of the second pump is stopped. On the other hand, even if the cooling request is received, the automatic stop condition is satisfied, and the temperature of the cooling water detected by the sensor is a predetermined execution temperature. When it is above, the cooling device of the internal combustion engine that executes the circulation process of circulating the cooling water in the heater cooling water path by opening the control valve and driving the second pump. When a value set to a temperature lower than the execution temperature is set as a stop temperature,
The control device stops driving of the second pump and closes the control valve when the temperature of the cooling water detected by the sensor during the execution of the circulation process becomes equal to or lower than the stop temperature. Item 2. The cooling apparatus for an internal combustion engine according to Item 1. When a value set to a temperature lower than the execution temperature is set as a stop temperature,
When the temperature of the cooling water detected by the sensor becomes equal to or lower than the stop temperature during execution of the circulation process, the control device drives the second pump while maintaining the open state of the control valve. The cooling device for an internal combustion engine according to claim 1, which stops. When the driving time of the second pump after the start of the circulation process is equal to or greater than a predetermined threshold, the temperature of the cooling water detected by the sensor during the execution of the circulation process is stopped. The cooling device for an internal combustion engine according to claim 2 or 3, wherein the driving of the second pump is stopped even if the temperature is exceeded.