JP2011179460A - Control device for engine cooling system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for an engine cooling system which improves knocking resistance even at restarting an engine. <P>SOLUTION: The cooling system 40 for cooling the engine 10 has a head side passage 51. With the operation of a head side water pump 53, cooling water is supplied through the head side passage 51 to a head side water jacket 52 and the cooling water circulating in the head side water jacket 52 returns to the head side passage 51. The head side WP 53 of an electric type is operated using electric power stored in a battery 24. A head side radiator 55 is provided at a position on the way of the head side passage 51. In this case, the operation of the head side water pump 53 is continued even after the engine 10 is stopped. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a control device for an engine cooling system.

  Conventionally, a configuration for cooling a cylinder head and a cylinder block by circulating cooling water is known as an engine cooling system (see, for example, Patent Document 1). For example, a mechanical pump that operates through power transmission from an engine crankshaft is known as a circulation pump. In this case, when the engine is in an operating state, the circulation pump operates and the cooling water flows to the cylinder head side. Or circulates on the cylinder block side. By actively cooling not only the cylinder block but also the cylinder head, the combustion chamber of the engine can be cooled, and the knocking resistance can be improved.

JP-A-8-144758

  Here, when the engine is stopped in a high temperature state, depending on the timing of engine restart, the temperature of the cylinder head at that time may be much higher than the temperature intended to improve knock resistance. is assumed. In this case, since the engine starts from the high state, fuel efficiency is deteriorated.

  In particular, in a vehicle that performs idling stop control that stops idling of an engine when it stops traveling at an intersection or the like, and in a hybrid vehicle that uses an engine and an electric motor as drive sources, the engine is frequently stopped and restarted. Therefore, the above problem is likely to occur.

  The present invention has been made in view of the above circumstances, and a main object of the present invention is to provide a control device for an engine cooling system that can improve knock resistance even when the engine is restarted.

  Hereinafter, means for solving the above-described problems and operational effects will be described.

  The present invention is applied to an engine cooling system that cools a cylinder head of an engine by circulating a fluid based on an operation of the electric pump, and controls the electric pump so as to cool the cylinder head. It is about. According to the first aspect of the present invention, the acquisition means for acquiring the temperature of the fluid at the detection target location in the cylinder head or the outlet portion thereof, and the target temperature of the detection target location are improved in knocking resistance. A temperature determining means for determining a temperature for the operation, and when the temperature acquired by the acquiring means exceeds a target temperature determined by the temperature determining means, the electric pump is operated even after the engine is stopped. Cooling control means for operating and cooling the cylinder head.

  According to this configuration, the cylinder head can be cooled to a temperature intended to improve knock resistance even after the engine is stopped. Thereby, even if the operation of the engine is restarted at an arbitrary timing, the temperature of the cylinder head is likely to become an appropriate temperature by that time. Therefore, the knocking resistance can be improved even when the engine is restarted.

  According to a second aspect of the present invention, in the first aspect of the present invention, the temperature determining means performs a process for determining the target temperature that is being executed during operation of the engine after the engine is stopped. It is also characterized by being continued. As a result, it is possible not only to improve the knocking resistance when the engine is restarted, but also to use the cooling control process during engine operation even after the engine is stopped, as in the case of engine operation. Is possible.

  The invention according to claim 3 is applied to an engine cooling system of a hybrid vehicle having an electric motor in addition to the engine as a power source in the invention according to claim 1 or 2, wherein the cooling control means After the stop, when the vehicle speed is equal to or higher than a predetermined value, the operation of the electric pump is continued even if the temperature acquired by the acquisition means falls below the target temperature. According to this configuration, even if the engine is stopped, if the vehicle speed is equal to or higher than a predetermined value, there is a high possibility that the engine will be restarted. That is, the engine operation is started even if the user's accelerator operation slightly increases. In such a situation, by continuing the operation of the electric pump, it is easier to suppress the occurrence of a rapid temperature rise of the cylinder head than when the operation of the electric pump is started after the engine is restarted.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the cooling control means is configured such that the temperature acquired by the acquisition means during the operation of the engine is equal to the target temperature. If it exceeds, the operating control means for setting the flow rate of the fluid supplied to the cylinder head to a reference flow rate or higher, and the temperature acquired by the acquisition means after the engine is stopped exceeds the target temperature. Even if the temperature difference is within a predetermined value, the flow rate of the fluid supplied to the cylinder head can be lower than the reference flow rate by reducing the energization amount of the electric pump. And a post-stop control means. According to this configuration, the cylinder head is cooled to an appropriate temperature either during operation of the engine or after the engine is stopped, and when the engine is stopped, the fluid temperature exceeds the target temperature. Even if the temperature difference is within a predetermined value, the energization amount of the electric pump is reduced. Thereby, the above excellent effects can be achieved while saving power for operating the electric pump.

  The invention according to claim 5 is applied to an engine cooling system including a radiator for cooling the fluid through heat exchange with outside air in the invention according to any one of claims 1 to 4, wherein the temperature determination is performed. The means acquires the outside air temperature and determines the target temperature so as to be equal to or higher than the acquired outside air temperature. Thereby, it is possible to prevent the operation of the electric pump from being continued even when the temperature of the fluid supplied to the cylinder head is lower than the outside air temperature or even when the temperature is higher than or equal to the outside air temperature. Therefore, the above-described excellent effects can be achieved while saving power for operating the electric pump.

  The invention according to claim 6 is the invention according to claim 5, wherein the radiator is provided at a position affected by heat radiation of an air conditioner condenser provided for cooling the refrigerant by heat exchange with outside air. When applied to an engine cooling system, the temperature determining means determines the target temperature so as to be equal to or higher than a temperature obtained by adding a numerical value corresponding to the amount of heat dissipation to the outside air temperature when heat dissipation is performed from the air conditioner capacitor. It is a thing to do. As a result, not only the outside air temperature but also the cooling efficiency of the fluid in the radiator is determined in consideration of the influence of heat radiation from the air conditioner capacitor, so that further power saving can be achieved.

  A seventh aspect of the present invention provides the radiator according to any one of the first to sixth aspects, wherein the fluid is cooled through heat exchange with outside air, and the electric fan that blows air toward the radiator. And when the temperature acquired by the acquisition means exceeds the target temperature determined by the temperature determination means, the electric fan is operated even after the engine is stopped. The cooling control unit includes an air blowing control unit that is operated, and the cooling pump control unit is configured to operate the electric pump even when the temperature acquired by the acquiring unit does not exceed the target temperature when the engine starts operating while the electric pump is stopped. Even if the engine starts operating while the electric fan is stopped, the air blowing control means When the temperature acquired by the obtaining means does not exceed the target temperature, the operation of the electric fan is started when the temperature exceeds the target temperature without starting the operation of the electric fan. It is characterized by.

  Compared to starting the operation of the electric pump when the temperature of the fluid exceeds the target temperature by starting the operation of the electric pump when the engine starts operating with the electric pump stopped. It becomes easy to suppress the occurrence of a rapid temperature rise of the cylinder head. On the other hand, even if the fluid is cooled in a situation where the temperature of the fluid does not exceed the target temperature, the cooling effect is low. Therefore, the electric fan does not start even when the engine starts to operate, and starts operation when the fluid temperature exceeds the target temperature, thereby saving power to operate the electric fan. Can be achieved.

The block diagram which shows the whole control system outline. (A) The figure for demonstrating the correspondence of head side water temperature and block side water temperature, and a fuel consumption, (b) In order to demonstrate a mode that the ignition timing corresponding to a trace knock approaches MBT with the fall of head side water temperature. Illustration. The flowchart which shows a cooling control process. The flowchart which shows the control processing of block side WP. The flowchart which shows the control processing of head side WP. The flowchart which shows the control process of the cooling fan. The time chart for demonstrating the mode of operation | movement of the cooling fan, the head side WP, and the block side WP. (A)-(c) The block diagram which shows the outline of another cooling system.

<First Embodiment>
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. In the present embodiment, the present invention is embodied in a so-called hybrid vehicle that travels by using any power of an engine and a motor generator as driving sources. FIG. 1 is a diagram showing a schematic configuration of a control system in a vehicle according to the present embodiment.

  As shown in FIG. 1, a vehicle to which the present control system is applied is equipped with an engine 10 as an internal combustion engine that generates power by combustion of fuel such as gasoline or light oil as main power generation means. The engine 10 includes a cylinder block 11 and a cylinder head 12. The cylinder block 11 is formed with a cylinder (not shown) that constitutes the cylinder, and a piston (not shown) is disposed in the cylinder. A cylinder head 12 is provided so as to block the inside of each cylinder from above, and the cylinder head 12 defines a combustion chamber at a position above each piston.

  The piston is pushed down by performing combustion using a mixture of fuel and air in the combustion chamber. An output shaft 13 (including a crankshaft) for transmitting torque of the engine 10 is connected to the power distribution unit 14. The power distribution unit 14 includes a planetary gear mechanism, whose planetary gear (not shown) has an output shaft 13 of the engine 10 and whose sun gear (not shown) communicates with a generator 15. The ring gear (not shown) is connected to a second rotating shaft 18 that communicates with the motor generator 17.

  Torque of the engine 10 is distributed to the first rotating shaft 16 and the second rotating shaft 18 via the power distribution unit 14. The second rotating shaft 18 is connected to the wheel 22 via the speed reducer 21, and the torque of the engine 10 distributed to the second rotating shaft 18 is transmitted to the wheel 22. Further, the generator 15 is operated by the torque distributed to the first rotating shaft 16, and the generated energy of the generator 15 is charged to the battery 24 as a DC power source via the inverter 23. The motor generator 17 is operated by the electric power of the battery 24, and the torque of the motor generator 17 is transmitted to the wheels 22 through the second rotating shaft 18.

  In this vehicle, the vehicle can be driven by the torque of both the engine 10 and the motor generator 17 during acceleration or high load, and the vehicle can be driven only by the torque of the motor generator 17 while the engine 10 is stopped during low speed running. Can be run. Further, when the vehicle is decelerated or braked, the engine 10 is stopped, and the motor generator 17 can regenerate travel energy to generate electric power and charge the battery 24. The battery 24 can be charged by setting the engine 10 to an operating state when the vehicle is stopped.

  The vehicle is provided with an air conditioning system 30 for cooling the passenger compartment. In the air conditioning system 30, the refrigerant is compressed and supplied to the condenser 32 by the operation of the variable capacity compressor 31. The condenser 32 is provided at the front portion of the vehicle, and cools the high-temperature / high-pressure refrigerant gas supplied from the compressor 31 using outside air to condense. The condensed and liquefied refrigerant is supplied to the liquid receiver 33. The liquid receiver 33 gas-liquid separates the refrigerant and temporarily stores the liquid refrigerant. The refrigerant in the liquid receiver 33 is rapidly expanded by the temperature type expansion valve 34 into a mist. The mist refrigerant is vaporized by heat exchange with the outside air by the evaporator 35. As a result, the conditioned air blown by a blower (not shown) can be cooled, and finally the passenger compartment can be cooled. Note that the compressor 31 is electrically operated and operates using electric power stored in the battery 24.

  The vehicle is provided with a cooling system 40 for cooling the engine 10. The cooling system 40 includes a block-side passage 41 for cooling the cylinder block 11 and a head-side passage 51 for cooling the cylinder head 12, and cooling water circulating through one of the passages is provided. It is the structure which does not circulate through the other channel | path.

  First, the block side passage 41 will be described. The block side passage 41 is connected to a block side water jacket 42 provided in the cylinder block 11. When the block-side water pump 43 (hereinafter referred to as the block-side WP 43) operates, cooling water is supplied to the block-side water jacket 42 through the block-side passage 41, and the cooling water circulated in the block-side water jacket 42 is It will return to the block side passage 41. The block side WP 43 is electrically operated and operates using the electric power stored in the battery 24. A block-side radiator 44 is provided in the middle of the block-side passage 41, and the cooling water that has reached a high temperature after passing through the block-side water jacket 42 is cooled when passing through the block-side radiator 44. The

  On the other hand, the head side passage 51 is connected to a head side water jacket 52 provided in the cylinder head 12. When the head-side water pump 53 (hereinafter referred to as the head-side WP 53) operates, cooling water is supplied to the head-side water jacket 52 through the head-side passage 51, and the cooling water circulated in the head-side water jacket 52 is The head side passage 51 is returned. The head side WP 53 is an electric type, and operates using electric power stored in the battery 24. A heater core 54 and a head side radiator 55 are provided in the middle of the head side passage 51.

  Cooling water that has passed through the head-side water jacket 52 is supplied to the heater core 54 before flowing into the head-side radiator 55. The conditioned air blown by the blower is sent to the heater core 54, and the conditioned air that has passed through the region where the heater core 54 is provided is generated using the cooling water supplied to the heater core 54 as a heat source. Finally, it becomes possible to warm the passenger compartment. Note that an air mix door (not shown) for adjusting the ratio of the amount of air passing through the heater core 54 and the amount of air bypassing the heater core 54 is provided between the evaporator 35 and the heater core 54 as part of the air conditioning system 30. Is provided.

  Cooling water that has passed through the head-side water jacket 52 and has reached a high temperature and has passed through the heater core 54 is cooled when it passes through the head-side radiator 55. Here, the head-side radiator 55 is provided in the front portion of the vehicle in an integrated state with the block-side radiator 44, but is provided closer to the outside air inflow side than the condenser 32 of the air conditioning system 30. Therefore, in the situation where heat is radiated in the condenser 32, the outside air heated by the heat exchange passes through the block-side radiator 44 and the head-side radiator 55.

  More specifically, the head-side radiator 55 is provided closer to the outside air inflow side than the block-side radiator 44. However, the present invention is not limited to this configuration, and the head-side radiator 55 may be provided closer to the outside air inflow side than the block-side radiator 44, and both the radiators 44 and 55 are aligned in the inflow direction of outside air. There may be no configuration.

  When the traveling speed (vehicle speed) of the vehicle is equal to or higher than a predetermined value, the outside air flows into the radiators 44 and 55 as described above, so that the cooling water flowing into the radiators 44 and 55 is naturally cooled. . On the other hand, when the vehicle speed becomes less than a predetermined value or when the vehicle is stopped, the cooling effect due to the inflow of outside air is reduced. Therefore, a cooling fan 56 is provided to supplement the cooling effect. . The cooling fan 56 is electrically operated and operates by using electric power stored in the battery 24. The cooling fan 56 is provided so as to blow air toward the head-side radiator 55 and the block-side radiator 44 at a destination of outside air from the head-side radiator 55, but is not limited thereto. For example, in a configuration in which the radiators 44 and 55 are provided so as not to line up in the inflow direction of the outside air, a cooling fan 56 may be provided individually for each of the radiators 44 and 55. Good.

  This control system includes an ECU 61 and an air conditioner ECU 62. The ECU 61 and the air conditioner ECU 62 are mainly configured by a microcomputer including a CPU, a ROM, a RAM, a backup area, and the like.

  The air conditioner ECU 62 drives and controls the compressor 31 based on various information acquired from the room temperature sensor 63 and the user interface 64 that detects the temperature in the vehicle interior, so that the vehicle in response to a request from the user made through the user interface 64. Keep room temperature.

  On the other hand, the ECU 61 executes fuel injection control by an injector, ignition timing control by an ignition device, and the like in the engine 10 and controls the operating state and regenerative state of the generator 15 and the motor generator 17. In addition to this, the ECU 61 detects the temperature of the cooling water at the outlet portion of the head-side water jacket 52 (hereinafter referred to as the head-side water temperature), and the temperature of the cooling water at the outlet portion of the block-side water jacket 42 ( Hereinafter, various detection results are fetched from the block water temperature sensor 66 for detecting the block side water temperature), the vehicle speed sensor 67 for detecting the vehicle speed, and the outside air temperature sensor 68 for detecting the outside air temperature. Based on the detection results, the block side WP43, the head side WP53, The cooling control of the cylinder block 11 and the cylinder head 12 is executed by controlling the driving of the cooling fan 56. Further, when executing such cooling control, the ECU 61 performs bidirectional communication with the air conditioner ECU 62 and takes in various information from the air conditioner ECU 62.

  Incidentally, the outside air temperature sensor 68 is provided so as to detect the temperature of the outside air flowing into the position where the condenser 32 and the radiators 44 and 55 are provided. Further, an ECU for controlling the engine 10 and an ECU for controlling the generator 15 and the motor generator 17 may be provided separately, and the former ECU may perform cooling control. The latter ECU Alternatively, the cooling control may be executed.

  Here, as shown in FIG. 2A, since the friction increases when the block side water temperature is low, the block side water temperature is preferably kept at a predetermined temperature (specifically, 85 ° C.). On the other hand, the head side water temperature is preferably lower because the knocking resistance is improved as the temperature of the combustion chamber is lowered. In particular, as shown in FIG. 2B, as the head side water temperature is lowered, the ignition timing at the time of the trace knock operation can be advanced, and the ignition timing can be brought closer to the MBT.

  Hereinafter, in a vehicle in which the engine 10 is stopped even when the ignition is on, such as a hybrid vehicle, the procedure of the cooling control process executed to suitably control the block side water temperature and the head side water temperature is as follows: This will be described with reference to the flowchart of FIG.

  The cooling control process is periodically executed in the ECU 61. Further, the cooling control process is not executed after the ignition OFF operation is performed. However, the present cooling control process is not limited to this. Even if the ignition OFF operation is performed, the cooling control process is periodically performed until the vehicle system is turned OFF. It is good also as a structure performed automatically.

  First, in step S101, various information is read. Specifically, the detection values of the head water temperature sensor 65, the block water temperature sensor 66, the vehicle speed sensor 67, and the outside air temperature sensor 68 are read. Further, information on the presence / absence of a cooling request from the air conditioner ECU 62 and information on the heat radiation amount of the capacitor 32 are acquired when there is a cooling request. The method of deriving the heat radiation amount of the capacitor 32 is arbitrary. For example, the heat radiation amount corresponding to the air conditioner load is prepared as a data table, and calculated from the detection result of the room temperature sensor 63 and the cooling request level for the user interface 64. For example, the amount of heat release may be derived in accordance with the cooling load (air conditioner load) to be performed, or the amount of heat release may be derived using, for example, the operating state of the compressor 31, the pressure of the refrigerant, the required cooling level, and the like. Good.

  In step S101, information on the presence / absence of a heating request is acquired from the air conditioner ECU 62, and if there is a heating request, information on the lower limit water temperature corresponding to the request is acquired. The method for deriving the information on the lower limit water temperature is arbitrary. For example, the lower limit water temperature corresponding to the heating load is prepared as a data table, and is calculated from the detection result of the room temperature sensor 63 and the heating request level for the user interface 64. The lower limit water temperature according to the heating load may be derived. Note that the function of executing the process of step S101 corresponds to an acquisition unit in this system.

  Thereafter, the water temperature threshold value α is calculated in steps S102 to S110. Note that the function of executing the calculation process corresponds to the temperature determining means in this system. The water temperature threshold value α is switched when the drive level of the head side WP 53 is switched by switching the energization amount to the head side WP 53, or when the drive level of the cooling fan 56 is switched by switching the energization amount of the cooling fan 56. This is a parameter used as a reference for the case. When the head side water temperature is higher than the water temperature threshold value α, the driving level of the head side WP 53 and the cooling fan 56 is higher than that when the head side water temperature is lower (that is, the level is higher). , A larger energization amount).

  Specifically, in step S102, it is determined whether or not there is a cooling request. If there is no cooling request, the water temperature threshold value α is set as “the outside air temperature detected by the outside air temperature sensor 68 +10” in step S103. Here, by determining the water temperature threshold value α corresponding to the outside air temperature in this way, the head side WP 53 and the cooling are performed regardless of whether the head side water temperature is lower than the outside air temperature or the outside air temperature is close to the outside air temperature. It can be prevented that the driving level of the fan 56 is maintained at a high level.

  On the other hand, if there is a cooling request, an additional temperature β for cooling is calculated in step S104. The calculation of the addition temperature β is performed using the heat radiation amount of the capacitor 32 acquired in step S101 and the inflow air velocity to the front portion of the vehicle provided with the capacitor 32 and the radiators 44 and 55. The inflow wind speed is calculated from the vehicle speed detected by the vehicle speed sensor 67 and the driving level of the cooling fan 56. Thereafter, in step S105, the water temperature threshold value α is set as “the outside air temperature detected by the outside air temperature sensor 68 + 10 + the added temperature β”. In this way, the water temperature threshold value α is calculated in consideration of the additional temperature β for cooling because the head-side radiator 55 is arranged on the inflow destination side of the outside air from the condenser 32, and the cooling water in the head-side radiator 55 is calculated. This is because the cooling efficiency is affected by the heat radiation from the capacitor 32. In addition, the addition value added to outside air temperature in step S103 and step S105 is not limited to "10", and is arbitrary, and the addition may not be performed.

  After calculating the water temperature threshold value α in step S103 or step S105, it is determined in step S106 whether or not the water temperature threshold value α is less than 40. If the water temperature threshold value α is less than 40, the water temperature threshold value α is reset to 40 in step S107. As already described, the knocking resistance improves as the head side water temperature decreases, but the effect converges at around 40 ° C. as shown in FIG. On the other hand, the water temperature threshold value α is a criterion for determining whether or not the drive level of the head side WP 53 and the cooling fan 56 is set to a relatively high state as described above, and the power consumption of the battery 24 increases as the drive level increases. Become. Therefore, the water temperature threshold value α is set in a range that does not fall below a predetermined lower limit value.

  Thereafter, it is determined whether or not there is a heating request in step S108, and if there is a heating request, it is further determined in step S109 whether or not the currently calculated water temperature threshold value α is less than the lower limit value in accordance with the heating request. To do. If it is less than the lower limit value, in step S110, the water temperature threshold value α is reset to the lower limit value in accordance with the heating request, and if it is equal to or higher than the lower limit value, such correction of the water temperature threshold value α is not performed. As already described, when heating is performed, warm air is sent to the passenger compartment using heat exchange with the cooling water supplied to the heater core 54, and if there is a heating request, The water temperature threshold value α is set so as to give priority.

  After executing the processing of step S102 to step S110, the control processing of the block side WP43 is executed in step S111, the control processing of the head side WP53 is executed in step S112, and the cooling fan in step S113. 56 control processes are executed. Thereafter, the cooling control process is terminated.

  Hereinafter, the processes in steps S111 to S113 will be described. First, the control processing of the block WP 43 in step S111 will be described with reference to the flowchart of FIG.

  In step S201, it is determined whether or not the block side WP 43 is stopped. If the block WP 43 is stopped, it is determined in step S202 whether or not the block water temperature is a start reference value (for example, 85 ° C.). If it is less than the start reference value, this process is terminated as it is, and if it is greater than or equal to the start reference value, the driving of the block side WP 43 is started in a low level state in step S203, and then this process is terminated.

  When the block WP 43 is being driven (step S201: NO), in step S204, it is determined whether or not the drive level is in a high level where the flow rate per unit time is higher than the low level. . Note that the energization amount to the block side WP 43 is larger in the high level state than in the low level state. If it is in the low level state, in step S205, it is determined whether or not the block side water temperature is equal to or higher than a high level setting reference value (for example, 100 ° C.). If it is equal to or greater than the reference value, the process is terminated after the drive level is changed to a high level in step S206.

  On the other hand, when the high level driving is being performed (step S204: YES), it is determined in step S207 whether the block-side water temperature is equal to or lower than a reference value (for example, 95 ° C.) for setting the low level. If it is below the reference value, the drive level is changed to a low level in step S208, and then this process ends.

  In step S209, it is determined whether or not the block-side water temperature is equal to or lower than a stop reference value (for example, 80 ° C.). If the block-side water temperature is equal to or lower than the stop reference value, the block-side WP 43 is stopped in step S210. After execution, this process is terminated.

  That is, the block-side WP 43 does not start to operate until the block-side water temperature reaches the start reference value, and the driving state is maintained until the block-side WP 43 is below the stop reference value that is slightly lower than the start reference value while the block-side WP 43 is being driven. . Thus, the block-side water temperature is basically maintained near the start reference value regardless of whether or not the engine 10 is operating. The start reference value is set as a block-side water temperature for suppressing the occurrence of friction and a block-side water temperature for preventing the heat burden on the cylinder block 11 from being applied so much.

  Next, the control processing of the head side WP 53 in step S112 will be described with reference to the flowchart of FIG. The function for executing this process corresponds to the cooling control means in this system.

  In step S301, it is determined whether or not the head side WP 53 is stopped. If the head-side WP 53 is stopped, it is determined in step S302 whether or not the engine 10 has started operation. If the operation has not been started, this processing is terminated as it is. If the operation has been started, the driving of the head side WP 53 is started in a low level state in step S303, and then this processing is terminated.

  If the head-side WP 53 is being driven (step S301: NO), it is determined in step S304 whether or not the engine 10 is stopped and the vehicle speed is “0”. If both conditions are not satisfied, it is determined in step S305 whether or not the drive level is in a high level where the flow rate per unit time is higher than the low level, and in step S306. It is determined whether or not the drive level is in a middle level where the flow rate per unit time is higher than the low level and the flow rate per unit time is lower than the high level.

  When the drive level is in the low level state (step S306: NO), in step S307, it is determined whether the vehicle speed is equal to or higher than the vehicle speed reference value (for example, 30 km / h), or the head side water temperature is immediately preceding step S102. -It is determined whether it is more than the water temperature threshold value alpha determined in step S110. If neither condition is satisfied, the present process is terminated as it is, and if any condition is satisfied, the process proceeds to step S308 to step S309. In step S308, the current water temperature threshold value α is stored as trigger information, and in step S309, the drive level is changed to the middle level. Thereafter, this process is terminated.

  As described above, even if the head side water temperature is not equal to or higher than the water temperature threshold value α, if the vehicle speed is equal to or higher than the vehicle speed reference value, the drive level is changed from the low level to the middle level, thereby starting the operation of the engine 10. This makes it possible to increase the cooling efficiency. Therefore, it is possible to suppress the head side water temperature from greatly exceeding the water temperature threshold value α.

  If the drive level is in the middle level (step S306: YES), it is determined in step S310 whether the head-side water temperature is equal to or higher than the upper limit water temperature (for example, 70 ° C.). This upper limit water temperature is set as a value larger than the value which water temperature threshold value (alpha) can take. If it is lower than the upper limit water temperature, it is determined in step S311 whether or not the vehicle speed is "vehicle speed reference value -15" or less and the head side water temperature is "timing information -10" or less. If both conditions are not satisfied, the present process is terminated. If both conditions are satisfied, the drive level is changed to a low level in step S312. On the other hand, if the head side water temperature is equal to or higher than the upper limit water temperature (step S310: YES), the drive level is changed to a high level in step S313. Thereafter, this process is terminated.

  If the drive level is in the high level state (step S305: YES), it is determined in step S314 whether or not the head side water temperature is equal to or lower than the “upper limit water temperature−10”. If the condition is not satisfied, the process is terminated as it is. If the condition is satisfied, the trigger information is first stored in step S315 as in steps S308 to S309, and the drive level is changed to the middle level in step S316. Thereafter, this process is terminated.

  Further, when the head side WP 53 is operating (step S301: NO), and when the engine 10 is stopped and the vehicle speed is “0” (step S304: YES), the process proceeds to step S317. In step S317, it is determined whether or not the head-side water temperature is equal to or higher than the water temperature threshold value α. If the head-side water temperature is lower than the water temperature threshold value α, the head-side WP 53 is stopped in step S318, and then this process ends. If it is equal to or higher than the water temperature threshold value α, it is determined in step S319 whether or not the head side water temperature is equal to or higher than the water temperature after adding a predetermined value (for example, 10) to the water temperature threshold value α. In other words, it is determined whether or not the amount of the head side water temperature exceeding the water temperature threshold value α is within a predetermined range.

  If the temperature is equal to or higher than the water temperature after the addition, the process is terminated after the drive level is set to the middle level in step S309. On the other hand, if the temperature is lower than the water temperature after addition, the process ends after the drive level is set to a low level in step S320.

  Next, the control process of the cooling fan 56 in step S113 will be described with reference to the flowchart of FIG. Note that the function of executing this processing corresponds to the air blowing control means in this system.

  In step S401, it is determined whether or not the cooling fan 56 is stopped. If the cooling fan 56 is stopped, it is determined in step S402 whether or not the vehicle speed is equal to or lower than the vehicle speed reference value. The vehicle speed reference value is the same as the vehicle speed reference value in the control process (FIG. 5) of the head side WP 53, but may be different. In step S403, it is determined whether the acceleration is equal to or less than an acceleration reference value. The acceleration is calculated based on the vehicle speed detected by the vehicle speed sensor 67. In step S404, it is determined whether the head-side water temperature is equal to or higher than the water temperature threshold value α.

  If any of the conditions in steps S402 to S404 is not satisfied, the present process is terminated. If all the conditions in steps S402 to S404 are satisfied, the process proceeds to steps S405 to S406. In step S405, the current water temperature threshold value α is stored as trigger information, and in step S406, driving of the cooling fan 56 is started in a high level state. Thereafter, this process is terminated. Incidentally, the trigger information stored in step S405 is stored separately from the trigger information stored in the control process of the head WP 53 (FIG. 5).

  If the cooling fan 56 is being driven (step S401: NO), it is determined in step S407 whether or not the engine 10 is stopped and the vehicle speed is “0”. If both conditions are not satisfied, it is determined in step S408 whether the vehicle speed is equal to or lower than the vehicle speed reference value. If the vehicle speed exceeds the vehicle speed reference value, the cooling fan 56 is turned on in step S409. After stopping, this process is terminated.

  That is, regardless of whether the head-side water temperature is equal to or higher than the water temperature threshold value α, the cooling fan 56 is maintained in a stopped state at a vehicle speed at which a cooling effect due to the inflow of outside air is expected. As a result, power saving of the battery 24 can be achieved. The power saving is also achieved because the condition that the acceleration is equal to or less than the acceleration reference value is set as the driving start condition of the cooling fan 56. Further, since such a condition is not set for the driving stop condition of the cooling fan 56, it is possible to prevent the ON / OFF of the cooling fan 56 from being repeated excessively. In order to prevent the ON / OFF repetition, the condition of acceleration is not set as described above, but the operation of the cooling fan 56 with respect to the timing when the head side water temperature becomes equal to or higher than the water temperature threshold α. It is good also as a structure which delays the timing which starts.

  If it is determined in step S408 that the vehicle speed is equal to or lower than the vehicle speed reference value, it is determined in step S410 whether or not the drive level is high. If it is at the high level, in step S411, it is determined whether or not the head-side water temperature is equal to or less than “Trigger Information-10”. If it is not “Trigger Information−10” or less, this processing is terminated as it is. If it is “Trigger Information−10” or less, the processing is terminated after the drive level is changed to a low level in Step S412. The low level is a state where the amount of blown air per unit time is smaller than the high level.

  If the drive level is at the low level (step S410: NO), it is determined in step S413 whether the head-side water temperature is equal to or higher than the water temperature threshold value α. If the temperature is lower than the water temperature threshold value α, the process is terminated as it is. If the temperature is equal to or higher than the water temperature threshold value α, the trigger information is first stored in step S414 as in steps S405 to S406, and the driving is performed in step S415. Change the level to high level. Thereafter, this process is terminated.

  If the cooling fan 56 is operating (step S401: NO), and if the engine 10 is stopped and the vehicle speed is “0” (step S407: YES), the process proceeds to step S416. In step S416, it is determined whether or not the head-side water temperature is lower than the water temperature threshold value α. Then, if it is equal to or higher than the water temperature threshold value α, the present process is terminated as it is, and if it is lower than the water temperature threshold value α, the cooling fan 56 is stopped in step S417, and then the present process is terminated.

  Next, the operation of the cooling fan 56, the head side WP 53, and the block side WP 43 will be described using the time chart of FIG. 7A shows the vehicle speed, FIG. 7B shows the engine rotation speed, and in FIG. 7C, the solid line shows the head side water temperature, the two-dot chain line shows the block side water temperature, and FIG. ) Shows the operation of the cooling fan 56, FIG. 7E shows the operation of the head side WP 53, and FIG. 7F shows the operation of the block side WP 43.

  In the situation where the ignition operation is performed by the user and the vehicle system is turned on, the accelerator operation is performed by the user at the timing t1. In this case, not only the motor generator 17 but also the engine 10 starts operating, and accordingly, the head side WP 53 starts operating in a low level state.

  Thereafter, at the timing of t2, when the head side water temperature becomes equal to or higher than the water temperature threshold value α, the cooling fan 56 starts operating in a high level state. Further, the drive level of the head side WP 53 is switched to the middle level. Then, when the vehicle speed becomes equal to or higher than the vehicle speed reference value at the timing of t3, the cooling fan 56 is stopped.

  Thereafter, the engine 10 is stopped at the timing t4. In this case, since the vehicle speed is not “0” and the head-side water temperature is equal to or higher than the water temperature threshold value α, the driving of the head-side WP 53 at the middle level is maintained. On the other hand, since the vehicle speed is maintained at or above the vehicle speed reference value, the cooling fan 56 remains stopped.

  Thereafter, the vehicle speed is decelerated, and at time t5, the vehicle speed becomes equal to or less than the vehicle speed reference value, so that the cooling fan 56 starts operating again in a high level state. At time t6, the head side water temperature falls below the water temperature threshold value α. However, in this case, since the vehicle speed is not “0”, both the cooling fan 56 and the head side WP 53 continue to be driven with the drive level changed to the low level. Thereafter, when the vehicle speed becomes “0” at the timing of t7, both the cooling fan 56 and the head-side WP 53 are stopped. In the above series of flows, since the block side water temperature is not equal to or higher than the start reference value, the block side WP 43 is maintained in a stopped state, and the block side water temperature continues to be raised.

  Thereafter, the accelerator operation by the user is performed again and the engine 10 starts operating at the timing t8, which is a state where the ON state of the vehicle system is continued, and accordingly, the head side WP 53 is at the low level. Start operation in state.

  Thereafter, at time t9, when the head side water temperature becomes equal to or higher than the water temperature threshold value α, the drive level of the head side WP 53 is switched to the middle level. However, since the acceleration exceeds the acceleration reference value this time, the cooling fan 56 is maintained in a stopped state.

  Thereafter, the operation of the engine 10 is continued and the amount of waste heat from the engine 10 increases, so that the block-side WP43 is in a low level at the timing t10 because the block-side water temperature becomes equal to or higher than the start reference value. Start operation with. Further, when the head side water temperature becomes equal to or higher than the upper limit water temperature at the timing of t11, the drive level of the head side WP53 is switched to the high level.

  The operation of the engine 10 is stopped at the timing t12, and accordingly, the temperature increase of the head side water temperature and the block side water temperature is stopped. Then, when the head side water temperature falls below the upper limit water temperature at the timing of t13, the drive level of the head side WP53 is switched to the middle level, and at the timing of t14, the block side WP43 is stopped when the block side water temperature becomes equal to or less than the stop reference value. State.

  Thereafter, the vehicle speed is further reduced, and the cooling fan 56 starts operating in a high level state when the vehicle speed becomes equal to or lower than the vehicle speed reference value at the timing t15. Then, the vehicle speed becomes “0” at the timing of t16. However, since the head-side water temperature is sufficiently higher than the water temperature threshold value α, the operation of the cooling fan 56 and the head-side WP 53 is maintained at the same drive level.

  Thereafter, at the timing of t17, the head side water temperature becomes “water temperature threshold value α + 10” or less, so the drive level of the head side WP 53 is switched to the low level. In addition, since the head side water temperature becomes equal to or lower than the water temperature threshold value α at the timing t18, both the cooling fan 56 and the head side WP 53 are stopped.

  According to the embodiment described in detail above, the following excellent effects are obtained.

  If the head-side water temperature is equal to or higher than the water temperature threshold value α after the engine 10 is stopped, the circulation of the cooling water is continued to cool the cylinder head 12. As a result, even if the engine 10 is stopped when the head-side water temperature is high, there is a high possibility that the temperature of the cylinder head 12 is lowered to a temperature intended to improve knocking resistance when the engine 10 is restarted. Become. Therefore, even when the engine 10 is restarted, the knocking resistance can be improved, and the fuel efficiency can be improved.

  Even if the engine 10 is stopped, if the vehicle speed is not “0”, the engine 10 is likely to be restarted. That is, even if the user's accelerator operation slightly increases, the operation of the engine 10 is started. In such a situation, the operation of the head side WP 53 is continued regardless of the head side water temperature. On the other hand, if the engine 10 is stopped and the vehicle speed is “0”, the head side WP 53 is stopped according to the head side water temperature. As a result, in a situation where there is a high possibility that the head side water temperature will rise, priority is given to lowering the head side water temperature rather than considering the power consumption of the battery 24, and it is natural that the cooling water is not circulated. In a situation where there is a high possibility that the head side water temperature will decrease, power saving of the battery 24 is given priority. Therefore, it is possible to keep the head side water temperature low while considering the power consumption of the battery 24.

  When the engine 10 is stopped and the vehicle speed is “0” when the head side WP 53 is operating, the drive level is suppressed to the middle level or lower, and the head side water temperature is equal to or higher than the water temperature threshold value α. However, if the temperature difference is within a predetermined value, the drive level is set to a low level. As a result, the power saving effect of the battery 24 can be enhanced in situations where there is a high possibility that the head-side water temperature will naturally decrease without circulating the cooling water.

  Even if the engine 10 is stopped, if the head-side water temperature is equal to or higher than the water temperature threshold value α, the cooling fan 56 is operated to cool the head-side cooling water. Thus, even when the vehicle speed is low after the engine 10 is stopped or when the vehicle is stopped, the cooling water can be actively cooled. Cooling can be performed early.

  Further, when the engine 10 starts operating in a state where the head side WP 53 is stopped, the operation of the head side WP 53 is started when the head side water temperature exceeds the water temperature threshold value α by starting the operation of the head side WP 53. Compared with the case of starting, it becomes easier to suppress the occurrence of the rapid temperature rise of the cylinder head 12. On the other hand, even if the cooling water is cooled in a situation where the head-side water temperature does not exceed the water temperature threshold value α, the cooling effect is low. Accordingly, the cooling fan 56 is operated by starting the operation when the head side water temperature exceeds the water temperature threshold value α without starting the operation even if the engine 10 starts the operation. Therefore, it is possible to save power for making it happen.

<Second Embodiment>
As shown in FIG. 8 (a), at the midpoint of the cooling water circulation passage, it branches into the block-side water jacket 42 side and the head-side water jacket 52 side, and passes through each of the water jackets 42, 52. After that, a configuration for controlling the head side water temperature and the block side water temperature as in the above embodiment is applied to the cooling system in which the radiator 71 and the water pump 72 are provided in the joined passage portion. Also good.

  Specifically, a flow rate control valve 73 is provided at a branch portion to each of the water jackets 42 and 52 when viewed in the direction of circulation of the cooling water, and the flow rate of the cooling water accompanying the operation of the water pump 72 based on the signal output from the ECU 61. Can be distributed between the cylinder head 12 side and the cylinder block 11 side, and a water temperature sensor is provided at the outlet of each water jacket 42, 52 so that the head side water temperature and the block side water temperature can be detected individually. To do. The ECU 61 controls not only the water pump 72 but also the flow rate control valve 73 to control the head side water temperature and the block side water temperature as in the above embodiment. For example, in a situation where it is not necessary to lower the block-side water temperature, the flow control valve 73 is set so that the cooling water flows only through the head-side water jacket 52, and the processing configuration of the above-described embodiment is left as it is for the control of the head-side water temperature. Applicable. On the other hand, in a situation where it is necessary to reduce not only the head side water temperature but also the block side water temperature, the flow rate control valve 73 allows the cooling water to flow through the block side water jacket 42 and the head side water jacket 52 respectively, The water pump 72 is driven and controlled so that the flow rate is higher than that in the above embodiment so that the water temperature can be controlled in the same manner as in the above embodiment.

  Further, in the configuration of FIG. 8A, a thermostat 74 is provided at a midway position in a non-branched passage, and a bypass passage 75 for preventing cooling water from flowing into the radiator 71 is provided. ing. Therefore, when the temperature of the cooling water is excessively low, it is possible to circulate the cooling water without flowing to the radiator 71 side. The thermostat 74 may be either a mechanical type or an electrical type, but if it is an electrical type, it is preferable to further provide a water temperature sensor that can detect the temperature of the cooling water flowing through the non-branched passage. Incidentally, the configuration in which the bypass passage 75 is provided in this way may be applied to the cooling system 40 in the first embodiment.

  As shown in FIG. 8B, the cooling water that has passed through the block-side water jacket 42 can be supplied to the head-side water jacket 52 as it is, or as shown in FIG. Bypass passages 76 and 77 are provided so that the cooling water having passed through the jacket 52 can be supplied to the block-side water jacket 42 as it is, and when the bypass passages 76 and 77 are used using a thermostat (not shown). It may be switched. In this case, when the cooling request for the entire engine 10 is high, cooling can be performed without distinguishing between the head side and the block side.

<Other embodiments>
The present invention is not limited to the description of the above embodiments, and may be implemented as follows, for example.

  The block side WP 43 is a mechanical type that operates through power transmission from the output shaft 13 of the engine 10, and the head side WP 53 is electrically operated so that the operation can be continued even after the engine 10 is stopped. It is good also as composition used as a formula. The block side water temperature is not less than the water temperature at which the friction can be reduced and not more than the water temperature at which the excessive temperature rise of the cylinder block 11 can be suppressed. Even if the cooling is not actively performed after the engine 10 is stopped, a problem hardly occurs. Therefore, it is possible to save power of the battery 24 by driving the block side WP 43 mechanically. On the other hand, by making the head side WP 53 electric, it is possible to improve the knocking resistance similarly to the above embodiment.

  In each of the above embodiments, the water temperature threshold value α is determined in the same processing mode during operation of the engine 10 and after it is stopped. However, the present invention is not limited to this. Thus, the method of determining the water temperature threshold value α may be changed. For example, the water temperature threshold value α may be set higher by a predetermined amount after the stop than during operation. However, the water temperature threshold value α is not a temperature intended to prevent excessive temperature rise, but needs to be a temperature intended to improve knocking resistance. In this case, the battery 24 can be saved.

  Even when the engine 10 is stopped, if the vehicle speed is not “0”, the head side WP 53 is not stopped even if the head side water temperature does not exceed the water temperature threshold value α. If it is larger than “0” and less than a predetermined speed (for example, 10 km), the head side WP 53 may be stopped when the head side water temperature does not exceed the water temperature threshold value α. In addition, the configuration may be applied to a hybrid vehicle that stops the engine 10 in a predetermined low vehicle speed range. In this case, the predetermined speed may be within the range of the low vehicle speed range.

  The cooling water supplied to the cylinder head 12 may be cooled by using heat exchange in the evaporator 35 of the air conditioning system 30.

  -Instead of the configuration in which the drive levels of the block side WP 43, the head side WP 53, and the cooling fan 56 are changed stepwise, the drive level may be changed continuously according to the block side water temperature or the head side water temperature. Good. Even in this case, when the engine 10 is in a stopped state and the vehicle speed is “0”, the engine 10 is in operation if the head side water temperature exceeds the water temperature threshold value α within a predetermined range. By saving the drive level as compared with the case of, power saving of the battery 24 is achieved.

  The head side WP 53 may be configured to start operating in accordance with fluctuations in the head side water temperature even when the engine 10 is stopped. In this case, even if the head-side WP 53 is stopped and the head-side water temperature rises when the engine 10 stops, the head-side WP 53 can be operated to cool the cylinder head 12 in response thereto. .

  The configuration in which the head-side water temperature and the block-side water temperature are controlled as in each of the above embodiments is such that the engine 10 always operates when the vehicle is running and the motor generator 17 operates auxiliaryly, and the engine 10 is when the vehicle is stopped. The present invention may be applied to a hybrid vehicle that performs idling stop control for stopping idling, and a vehicle that performs idling stop control although not hybrid. Further, the configuration for controlling the head side water temperature and the block side water temperature as in each of the above embodiments is applied to a vehicle in which the engine 10 is the only means for generating power when the vehicle is running and the idling stop control is not performed. May be. In this case, the processing after the engine 10 is stopped in the first embodiment may be executed after the ignition OFF operation. Moreover, you may apply to the vehicle with a supercharger. In such a vehicle, the combustion efficiency can be improved by increasing the compression ratio, but knocking is likely to occur. However, the high compression ratio can be improved by reducing the head side water temperature and improving the knocking resistance. It becomes easy to realize.

  DESCRIPTION OF SYMBOLS 10 ... Engine, 11 ... Cylinder block, 12 ... Cylinder head, 17 ... Motor generator, 24 ... Battery, 31 ... Compressor, 32 ... Condenser, 40 ... Cooling system, 51 ... Head side passage, 52 ... Head side water jacket, 53 ... Head side WP, 55 ... Head side radiator, 56 ... Cooling fan, 61 ... ECU, 65 ... Head water temperature sensor.

Claims (7)

In a control device for an engine cooling system that is applied to an engine cooling system that cools a cylinder head of an engine by circulating a fluid based on an operation of the electric pump, and that controls the electric pump to cool the cylinder head.
An acquisition means for acquiring a temperature of the fluid at a detection target location in the cylinder head or an outlet portion thereof;
Temperature determining means for determining the target temperature of the detection target portion as a temperature for improving the knocking resistance;
Cooling control for operating the electric pump to cool the cylinder head even after the engine is stopped when the temperature acquired by the acquiring unit exceeds the target temperature determined by the temperature determining unit Means,
An engine cooling system control device comprising:   The said temperature determination means continues the process for determining the said target temperature currently performed during operation | movement of the said engine even after the said engine stops. Control device for engine cooling system. Applied to an engine cooling system of a hybrid vehicle including an electric motor in addition to the engine as a power source,
The cooling control means continues the operation of the electric pump even when the temperature acquired by the acquisition means falls below the target temperature when the vehicle speed is equal to or higher than a predetermined value after the engine is stopped. The control device for an engine cooling system according to claim 1 or 2, wherein the control device is an engine cooling system. The cooling control means includes
During operation of the engine, when the temperature acquired by the acquisition unit exceeds the target temperature, an operation control unit that sets a flow rate of the fluid supplied to the cylinder head to a reference flow rate or higher,
Even if the temperature acquired by the acquisition means exceeds the target temperature after the engine is stopped, the energization amount of the electric pump is reduced if the temperature difference is within a predetermined value. And a post-stop control means for setting the flow rate of the fluid supplied to the cylinder head to a flow rate lower than the reference flow rate,
The engine cooling system control device according to any one of claims 1 to 3, further comprising: Applied to an engine cooling system comprising a radiator for cooling the fluid through heat exchange with outside air;
The engine according to any one of claims 1 to 4, wherein the temperature determination unit acquires an outside air temperature and determines the target temperature so as to be equal to or higher than the acquired outside air temperature. Control device for cooling system. Applied to an engine cooling system in which the radiator is provided at a position affected by heat radiation of an air conditioner capacitor provided to cool the refrigerant by heat exchange with outside air;
The temperature determining means is configured to determine the target temperature so as to be equal to or higher than a temperature obtained by adding a numerical value corresponding to the amount of heat dissipation to the outside air temperature when heat dissipation is performed from the air conditioner capacitor. The engine cooling system control device according to claim 5. Applied to an engine cooling system comprising a radiator for cooling the fluid through heat exchange with outside air, and an electric fan for blowing air toward the radiator,
When the temperature acquired by the acquisition means exceeds the target temperature determined by the temperature determination means, the apparatus includes a blower control means for operating the electric fan even after the engine is stopped,
When the engine starts operating while the electric pump is stopped, the cooling control means starts the operation of the electric pump even if the temperature acquired by the acquiring means does not exceed the target temperature. ,
The air blowing control means does not start the operation of the electric fan if the temperature acquired by the acquisition means does not exceed the target temperature even if the engine starts operating while the electric fan is stopped. 7. The engine cooling system control device according to claim 1, wherein the operation of the electric fan is started when the temperature exceeds the target temperature.

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