Control device

Abstract

Control device attached to a vehicle (100) containing an internal combustion engine (13) as a power source, the control device comprising: an internal combustion engine output power control unit (31) that outputs internal combustion engine control information to the internal combustion engine (13) for controlling an output power of the internal combustion engine (13); an internal combustion engine output power prediction unit (32) that, based on position information of the vehicle (100) acquired by a positioning unit that measures a position of the vehicle (100), traffic information relating to a route to a destination, and the internal combustion engine control information, predicts an output power of the internal combustion engine (13) at a future prediction time; a target coolant temperature determination unit (33),a unit that determines a target coolant temperature based on the predicted output power of the internal combustion engine (13), which is a target temperature of a coolant for cooling the internal combustion engine (13); a change-time setting unit (34) that, based on the predicted output power of the internal combustion engine (13), sets a change-time to change the temperature of the coolant to the target coolant temperature; and a coolant temperature change control unit (35) that controls the operation of a coolant temperature change unit, which changes the temperature of the coolant at the change-time, based on the predicted output power of the internal combustion engine (13), in such a way that the target coolant temperature is reached, whereby the output power of the internal combustion engine (13) is changed in accordance with a load of the internal combustion engine (13) during the prediction time period.wherein the target coolant temperature determination unit (33) determines the target coolant temperature to be higher while the predicted output power of the internal combustion engine (13) is lower, and the target coolant temperature is determined to be lower while the predicted output power of the internal combustion engine (13) is higher, and wherein the change-time setting unit (34) sets as the change-time a time at which the predicted output power of the internal combustion engine (13) changes from a low output power to a high output power, or a time at which the predicted output power of the internal combustion engine (13) changes from a high output power to a low output power, wherein the change-time setting unit (34) sets an earlier time than a timeto which the output power of the internal combustion engine (13) changes from a high output power to a low output power, as the change time is set when the internal combustion engine output power prediction unit (32) predicts that a duration during which the internal combustion engine (13) stops is equal to or longer than a set duration after the output power of the internal combustion engine (13) has changed from a high output power to a low output power.

Description

Technical FieldThe present invention relates to a control device mounted on a vehicle.Prior ArtIn order to cope with vehicle fuel consumption regulations which are being tightened annually, the market for hybrid vehicles having a strong fuel consumption reducing effect is expanding. A hybrid vehicle includes, as power sources, an (electric) motor and an engine, and can efficiently drive the vehicle by driving both the motor and the engine according to a traveling condition. At the time of deceleration, kinetic energy of the vehicle is recovered using the engine as a generator and stored in a secondary battery (power storage device), and the engine running is performed using the stored energy, thereby reducing fuel consumption.In recent years, from the viewpoint of energy saving and economical driving, further improvement in fuel economy of vehicles is desired. In order to improve fuel economy of a vehicle, it is important to suppress wasteful power consumption. Thus, a technique for executing engine control disclosed in PTL 1 has been provided. PTL 1 discloses that "when a change in the operating state of the engine is predicted from a travel plan, the foregoing control for preliminarily controlling the control command value of the engine operation control device is started before the predicted change in the traveling state of the engine occurs".GB 2 552 501 A discloses a vehicle having a temperature controller for controlling an operating temperature of an engine by controlling a flow of coolant through the engine. Here, based on a current position of the vehicle and map data, a future vehicle state such as a speed is estimated, and based thereon, a target temperature of the engine for a future time is set.List of ReferencesPatent LiteraturePTL 1: JP 2016-210 243 ASUMMARY OF THE INVENTIONTechnical ProblemMeanwhile, in the foregoing control for decreasing the water temperature disclosed in PTL 1, the coolant temperature is decreased in advance by decreasing the opening degree of the flow rate control valve or by increasing the supply power to the electric water pump. Thus, the control for decreasing the coolant temperature is ended when the coolant temperature becomes equal to or lower than a predetermined target temperature. However, a vehicle travels under various traveling conditions such as a freeway and an uphill road, and the engine or the like cannot be sufficiently cooled by only the coolant by preparing a certain target temperature, and knocking may occur. Conversely, if a vehicle travels in a city area or the like, if the engine or the like is cooled too much, the cooling loss of the engine occurs. In either case, overload is applied to the engine and fuel economy may be reduced.The invention has been made in view of such a situation, and an object thereof is to appropriately change the temperature of the coolant according to a running condition of a vehicle.Solution of the ProblemThe invention relates to a control device having the features of claim 1 or the features of claim 12.Advantageous Effects of the InventionAccording to the invention, a target coolant temperature is determined in accordance with the output of an internal combustion engine predicted in a future prediction period, and a coolant temperature is changed so as to reach the target coolant temperature. Thus, overloading of the internal combustion engine is avoided and fuel economy of the vehicle can be improved.Objects, configurations, and effects other than the above description will be apparent from the explanation of the following embodiments.Brief Description of the DrawingsFIG. 1 is a schematic configuration diagram illustrating an example in which a control device mounted on a hybrid vehicle according to a first embodiment of the invention is applied to a series hybrid vehicle. FIG. 2 is a block diagram illustrating a hardware configuration example of a VCU according to the first embodiment of the invention. FIG. 3 is a system diagram illustrating a flow path of a coolant in a cooling system including an electric thermostat according to the first embodiment of the invention. FIG. 4 is a block diagram illustrating a functional configuration example of the VCU according to the first embodiment of the invention. FIG. 5 is a graph illustrating a relationship between the operation of the electric thermostat and the operation of an electric water pump with respect to an engine load in a prediction period according to the first embodiment of the invention. FIG. 6 is an explanatory diagram illustrating an example of a target coolant temperature determined based on a predicted vehicle speed and a predicted engine output according to the first embodiment of the invention. FIG. 7 is an explanatory diagram illustrating an example of a target coolant temperature determined based on a predicted fuel speed and a predicted engine output according to a second embodiment of the invention. FIG. 8 is a graph illustrating a relationship between predicted engine output and target coolant temperature in a prediction period according to a third embodiment of the invention. FIG. 9 is a system diagram illustrating a flow path of a coolant in a cooling system including an MCV according to a fourth embodiment of the invention. FIG. 10 is a graph illustrating a relationship between a valve opening degree of each inflow valve of the MCV and the flow rate of the electric water pump with respect to the engine load in the prediction period according to the fourth embodiment of the invention. FIG. 11 is a system diagram illustrating a flow path of a coolant in a cooling system including a heater according to a fifth embodiment of the invention. FIG. 12 is a graph illustrating an example of a change in the valve opening degree of each inflow valve with respect to the temperature of the coolant according to the fifth embodiment of the invention. FIG. 13 is a cross-sectional view illustrating an example of an internal combustion engine to which an engine oil nozzle according to a sixth embodiment of the invention is applied. FIG. 14 is a graph illustrating a relationship of a flow rate of an oil nozzle with respect to an engine load in a prediction period according to the sixth embodiment of the invention.DESCRIPTION OF EMBODIMENTSHereinafter, embodiments of the invention will be described with reference to the drawings. In the present specification and the drawings, components having substantially the same function or configuration are denoted by the same reference numerals, and the redundant description is omitted.[First Embodiment]FIG. 1 is a schematic configuration diagram illustrating an example in which a control device mounted on a hybrid vehicle according to a first embodiment of the invention is applied to a series hybrid vehicle.A navigation device 11 may receive GPS signals transmitted from a plurality of global positioning system (GPS) satellites over the hybrid vehicle 100 including an internal combustion engine (engine 13) as a drive source on a satellite radio wave, measure a current position, and display the current position of a hybrid vehicle 100 by superimposing the current position on a map displayed on a display device in the hybrid vehicle 100. For obtaining the current position by the navigation device 11, a base station of a mobile phone terminal, an access point of Wi-Fi (registered trademark), or the like may also be used together. Information on the current position of the hybrid vehicle 100 measured by the navigation device 11 and map information including the environment where the hybrid vehicle 100 travels and the route to the destination are output to a vehicle control device, i.e., a vehicle control unit (VCU) 1.In an interior of the hybrid vehicle 100, an accelerator depression degree sensor 6 and a brake switch 7 are provided. The accelerator pedal depression degree sensor 6 detects a depression degree of an accelerator pedal, i.e., an accelerator pedal depression degree. The brake switch 7 detects whether the brake pedal is depressed.The engine 13 is a four-cylinder gasoline engine for a vehicle using spark ignition type combustion, and is an example of an internal combustion engine. The engine 13 includes a starter 12 for starting the engine 13, and a crank shaft of the engine 13 is provided with a crank angle sensor 10 for detecting its rotational angle, while the other end of the crank shaft is connected to a generator 14.A generator control device, i.e., a generator control unit (GCU) 3, controls driving of the generator 14 via a converter 15 such that the converter 15 can charge a battery 16 at a predetermined voltage. The generator 14 is driven by the engine 13 to generate power, and charges the battery 16 via the inverter 15.A battery control device, i.e., a battery control unit (BCU) 4, controls charging and discharging of the battery 16 based on a battery request output from the VCU 1. The battery 16 is provided with a battery voltage sensor 9 that measures the internal voltage of the battery 16, and the VCU 1 constantly checks the voltage of the battery 16.A motor control device, i.e., a motor control unit (MCU) 5, controls a converter 17 (and a motor 18) based on a motor request output from the VCU 1. Power is supplied to the inverter 17 from the battery 16 which is electrically connected. Then, the inverter 17 converts DC power discharged from the battery 16 into AC power and supplies the AC power to the motor 18. The motor 18 is connected to a wheel 20 through a speed reduction gear 19. On an input shaft of the wheel 20, a vehicle speed sensor 8 is provided.Each signal output from the vehicle speed sensor 8, the battery voltage sensor 9, and the crank angle sensor 10 is sent to the VCU 1. Signals output from the accelerator depression degree sensor 6 and the brake switch 7 are also sent to the VCU 1.The VCU 1 is mounted on a vehicle (hybrid vehicle 100) that travels by an output of an internal combustion engine (engine 13) and / or an electric drive unit (motor 18). The VCU 1 calculates a required driver torque based on the output signal of the accelerator depression degree sensor 6. That is, the accelerator depression degree sensor 6 is used as a requested torque detection sensor that detects the requested torque for the engine 13 and the motor 18. Further, the VCU 1 determines the presence or absence of a driver's deceleration request based on the output signal of the brake switch 7. In addition, the VCU 1 calculates the remaining amount of power of the battery 16 based on the output signal of the battery voltage sensor 9. the VCU 1 calculates the rotational speed of the engine 13 based on the output signal of the crank angle sensor 10.The engine request output calculated by the VCU 1 is sent to the engine control device, i.e., an engine control unit (ECU) 2. The ECU 2 controls the engine 13 based on the request output from the VCU 1. More specifically, the ECU 2 controls the starter 12 in addition to a fuel injection unit, an ignition unit, and a throttle valve (not shown). The battery request output calculated by the VCU 1 is sent to the BCU 4.An internal configuration of the VCU 1 in the first embodiment will be described below. FIG. 2 is a block diagram illustrating a hardware configuration example of the VCU 1.Each output signal outputted from the accelerator depression degree sensor 6, the brake switch 7, the vehicle speed sensor 8, the battery voltage sensor 9 and the crank angle sensor 10 is inputted to an input circuit 1a of the VCU 1. However, the input signal is not limited thereto. An input signal of each sensor input to the input circuit 1a is sent to an input port (not shown) in an input / output port 1b. The value transmitted to the input port is stored in a RAM 1c and processed by the CPU 1e. A control program describing the contents of the arithmetic processing has been written in a ROM 1d in advance.A value indicating the operation amount of the control target (the engine 13, the generator 14, the battery 16, the motor 18, and the like) calculated according to the control program is stored in the RAM 1 cand then transmitted to an output port (not illustrated) in the input / output port 1 band transmitted to each device via each output unit. Here, examples of the output unit include an engine control output unit 1 f, a motor control output unit 1 g, a battery control output unit 1 h, and a generator control output unit 1 i. The circuits of these output units are connected to the ECU 2, the MCU 5, the BCU 4, and the GCU 3. In FIG. 2, the control device to be controlled (ECU 2, MCU 5, BCU 4, and GCU 3) is provided separately from the VCU 1, but the invention is not limited to this mode, and a functional unit corresponding to the control device of each device may be provided in the VCU 1.FIG. 3 is a system diagram illustrating a flow path of a coolant in a cooling system including an electric thermostat 22.In the hybrid vehicle 100, a flow path is provided through which a coolant for cooling a high temperature portion flows during traveling. As the coolant, for example, cooling water (coolant) mixed with antifreeze is used. The hybrid vehicle 100 according to this embodiment includes a radiator 21, an electric thermostat 22, an electric water pump 23, a cylinder block 24, a cylinder head 25, and a water outlet 26.The radiator 21 cools the coolant by heat exchange between the coolant and the traveling air.A coolant temperature changing unit, the operation of which is controlled by a coolant temperature changing control unit 35 illustrated in FIG. 4 to be described later, includes a coolant merging unit (an electric thermostat 22) and a variable flow rate unit (electric water pump 23).The coolant merging unit (electric thermostat 22) is provided to be capable of drawing the coolant into a merging portion of a first flow path (the flow path P 1) through which the coolant circulates in the internal combustion engine (engine 13) and a second flow path (the flow path P 2) through which the coolant circulates in the internal combustion engine (engine 13) and the radiator (radiator 21), opening a valve (inflow valve V 1) in accordance with the temperature of the coolant to allow the coolant to flow from the second flow path (flow path P 2), and merging and receiving the coolant. For example, the electric thermostat 22 includes the inflow valve V 1 that is connected to the flow path P 2 and into which the coolant from the radiator 21 flows. The coolant that has flowed into the inflow valve V 1 flows out to the electric water pump 23. The electric thermostat 22 has a fail-safe function of opening the inflow valve V 1 to decrease the temperature of the coolant when the temperature of the coolant exceeds a predetermined temperature (e.g., a specific temperature of 60 degrees to 100 degrees). As illustrated in FIG. 5 to be described later, the VCU 1 changes the valve opening temperature to open the inflow valve V 1 of the electrostatic thermostat 22 in accordance with the load of the engine 13 to control the operation of the electric thermostat 22.The variable flow rate unit (electric water pump 23) varies the flow rate of the coolant sucked into the coolant joining unit (electric thermostats 22) and circulates the coolant on the first flow path (flow path P 1) or on the second flow path (flow path P 2). The electric water pump 23 is driven and controlled by the VCU 1, and when the predicted engine output of the engine 13 increases, the electric water pump cools the engine 13 by causing the coolant to flow through the flow paths P 0 and P 2, so that the coolant circulates between the radiator 21 and the engine 13. On the other hand, the electric water pump 23 prevents the coolant from flowing to the radiator 21 when the predicted engine output of the engine 13 decreases so that the coolant flows to the flow path P 1 to suppress the cooling of the engine 13. Note that the electric water pump 23 can be driven by electric power supplied from the battery 16 even when the hybrid vehicle 100 is stopped.The cylinder block 24 supports a cylinder including a piston and a connecting rod provided in the engine 13, and a crankcase accommodating a crankshaft.The cylinder head 25 is fixed to an upper portion of the cylinder block 24, and includes a camshaft, an intake / exhaust valve, a combustion chamber, and the like. In the following description, the cylinder block 24 and the cylinder head 25 may be collectively referred to as an engine 13.Between the cylinder head 25 and the radiator 21, the water outlet 26 is provided and causes the coolant flowing from the cylinder head 25 to flow out to the radiator 21. In addition, the coolant may be recirculated from the water outlet 26 to the cylinder head 25.In the drawing, the normal flow path P 0 of the coolant is illustrated by a solid line, the flow path P 2 when the inflow valve V 1 of the electric thermostat 22 is opened is illustrated by a broken line, and the flow path P 1 when the inflow valve V 1 is closed is illustrated by a broken line. In the normal flow path P 0, the coolant is accumulated between the water pump 23 and the radiator 21. The coolant on the normal flow path P 0 remains accumulated unless the inflow valve V 1 is opened and the coolant flows from the flow path P 2. Then, the coolant circulates on the flow path P 1 without flowing toward the radiator 21.For example, when the hybrid vehicle 100 travels at high speed, the cylinder block 24 and the cylinder head 25 have high heat, so that the supply valve V 1 is opened. When the inflow valve V 1 is opened, the coolant flows through the flow paths P 0 and P 2 in the order of the cylinder block 24, the cylinder head 25, the water outlet 26, and the radiator 21 by the electric water pump 23, circulates again in the electric thermostat 22, and flows into the electric water pump 23, thus the coolant that has taken heat from the cylinder block 24 and the cylinder head 25 is efficiently cooled by the radiator 21.When the hybrid vehicle 100 keeps idling or running at low speed, the supply valve V 1 is closed because heat generation of the cylinder block 24 and the cylinder head 25 is small. When the inflow valve V 1 is closed, the coolant flows through the flow path P 1 bypassing the radiator 21. That is, the coolant flows in the order of the cylinder block 24 and the cylinder head 25 by the electric water pump 23 via the flow path P 1, circulates in the electric thermostat 22 again, and flows into the electric water pump 23, thus the coolant is not excessively cooled by the radiator 21.FIG. 4 is a block diagram illustrating a functional configuration example of the VCU 1 according to the first embodiment.The VCU 1 includes an engine output control unit 31, an engine output prediction unit 32, a target coolant temperature determination unit 33, a change timing setting unit 34, and a coolant temperature change control unit 35.An engine output control unit (the engine output control unit 31) outputs, to the engine (engine 13), engine control information (engine control information) for controlling the output of the engine (engine 13). The engine control information of the engine 13 controlled by the engine output control unit 31 is input to the engine output prediction unit 32.An engine output prediction unit (engine output prediction unit 32) predicts, based on position information of a vehicle (hybrid vehicle 100) detected by a position determination unit (navigation device 11) that measures a position (current position) of the vehicle (hybrid vehicle 100), traffic information related to a route to a destination, and engine control information (engine control information) predicts an output of an engine (engine 13) in a future prediction period. The output of the internal combustion engine (engine 13) changes depending on the load of the internal combustion engine (engine 13) in the prediction period. Here, the engine output prediction unit (engine output prediction unit 32) predicts the output of the engine (engine 13) in the prediction period based on the vehicle speed of the vehicle (hybrid vehicle 100). For example, the vehicle speed when the vehicle (hybrid vehicle 100) is traveling on a freeway is a higher value than when the vehicle (hybrid vehicle 100) is traveling in a city area. The engine output prediction unit (engine output prediction unit 32) then predicts the maximum value of the output of the engine (engine 13) in the prediction period as the output of the engine (engine 13).A target coolant temperature determination unit (target coolant temperature determination unit 33) determines a target coolant temperature that is a target temperature of coolant for cooling the internal combustion engine (engine 13) based on the predicted output of the internal combustion engine (engine 13). Here, the target coolant temperature determination unit (target coolant temperature determination unit 33) determines the target coolant temperature to be higher while the predicted output of the internal combustion engine (engine 13) is lower, and determines the target coolant temperature to be lower while the predicted output of the internal combustion engine (engine 13) is higher.A change timing setting unit (change timing setting unit 34) sets a change timing for changing the temperature of the coolant to the target coolant temperature based on the predicted output of the internal combustion engine (engine 13). Here, the change timing setting unit (change timing setting unit 34) sets, as the change timing, a timing at which the predicted output of the internal combustion engine (engine 13) changes from low output to high output or a timing at which the predicted output of the internal combustion engine (engine 13) changes from high output to low output.A coolant temperature change control unit (coolant temperature change control unit 35) controls the operation of the coolant temperature change unit (the electric thermostat 22 and the electric water pump 23) that changes the temperature of the coolant at the change timing, based on the predicted output of the internal combustion engine (the engine 13) such that the coolant temperature becomes the target coolant temperature.Note that the engine output prediction unit (engine output prediction unit 32) may predict the average value of the output of the engine (engine 13) in the prediction period as the output of the engine (engine 13). In this case, the target coolant temperature determination unit (target coolant temperature determination unit 33) determines the target coolant temperature to be high when the average value is equal to or less than the set average value, and determines the target coolant temperature to be low when the average value exceeds the set average value.FIG. 5 is a graph illustrating a relationship between the operation of the electric thermostat 22 and the operation of the electric water pump 23 with respect to the engine load in the prediction period.The coolant temperature change control unit (coolant temperature change control unit 35) operates the coolant merging unit (the electric thermostats 22) at a higher coolant temperature while the predicted output of the internal combustion engine (engine 13) is lower to circulate the coolant to the first flow path (flow path P 1) and decrease the flow rate of the coolant flowing out from the variable flow rate unit (electric water pump 23), or operates the coolant merging unit (the electric thermostats 22) at a lower coolant temperature while the predicted output of the internal combustion engine (engine 13) is higher to circulate the coolant to the second flow path (flow path P 2) and increase the flow rate of the coolant flowing out from the variable flow rate unit (electric water pump 23).In the graph ( 1) of FIG. 5, the horizontal axis represents the engine load in the prediction period and the vertical axis represents the opening temperature at which the inflow valve V 1 of the electric thermostat 22 opens. For example, the opening temperature of the inflow valve V 1 is high when the engine load in the prediction period, i.e., the engine output of the engine 13, is low. Thus, as illustrated on the flow path P 1 in FIG. 3, the coolant does not flow to the radiator 21, but the opening temperature of the inflow valve V 1 decreases as the engine load increases. That is, as illustrated on the flow path P 2 of FIG. 3, at a high engine load, the inflow valve V 1 is opened and the coolant flowing over the radiator 21 is sufficiently cooled and circulated.In the graph ( 2) of FIG. 5, the horizontal axis represents the engine load in the prediction period and the vertical axis represents the flow rate of the electric water pump 23. when the engine load in the prediction period, i.e., the engine output of the engine 13, is low, the coolant flows only through the flow path P 1 illustrated in FIG. 3. Thus, the flow rate of the electric water pump 23 is small, and the flow rate of the coolant circulating through the flow path P 1 is small. However, the inflow valve V 1 of the electric thermostat 22 opens and the coolant flows through the flow path P 2 in addition to the flow path P 1, so that the flow rate of the electric water pump 23 increases as the engine load increases. That is, at a high engine load, the flow rate of the electric water pump 23 increases, and the flow rate of the coolant flowing through the flow path P 2 also increases, so that the flow rate of the coolant cooled by the radiator 21 increases. Thus, the coolant can sufficiently cool the engine 13 including the cylinder block 24 and the cylinder head 25.FIG. 6 is an explanatory diagram illustrating an example of a target coolant temperature determined based on a predicted vehicle speed and a predicted engine output. The future prediction time period starting from the present is here, for example, 3 minutes.When the stopped hybrid vehicle 100 starts to travel, the predicted vehicle speed increases. For example, acceleration, deceleration, and stop of the hybrid vehicle 100 frequently occur, and the generation or stop of a low predicted engine output is repeated when the hybrid vehicle 100 travels in a city area.In urban areas, there are several periods of time during which the predicted engine output power does not occur, so the target coolant temperature is substantially constant T L. In this period, the inflow valve V 1 is closed, and the coolant flows through the flow path P 1 while not passing through the radiator 21. Note that T L, which represents the target coolant temperature, is a value corresponding to a depth of the predicted engine output power.When the output of the hybrid vehicle 100 changes from low to high, the period in which the predicted engine output is generated increases even when the predicted engine output is low, and the heat generation of the engine 13 tends to be high. Thus, the target coolant temperature is changed to T M, lower than T L. At this time, the inflow valve V 1 is opened and the coolant flows through the radiator 21 via the flow paths P 0 and P 2, however, the flow rate per unit time of the coolant flowing toward the radiator 21 is controlled to be smaller by the electric water pump 23. The T M, which represents the target coolant temperature, is a value corresponding to a mean (low to high in the drawing) of the predicted engine output.When the hybrid vehicle 100 is traveling on a highway, a high engine output is required, so that the predicted engine output also increases. In addition, the engine 13 tends to have a high temperature because the high predicted engine output continues for a long period of time. In order to sufficiently cool the engine 13, the target coolant temperature is changed to T H, lower than T M. Further, the flow rate per unit time of the coolant flowing toward the radiator 21 is controlled to be larger by the electric water pump 23. At this time, coolant flows via the flow paths P 0 and P 2 via the radiator 21, thereby sufficiently cooling the coolant. Note that T H, which represents the target coolant temperature, is a value corresponding to a high of the predicted engine output power.When the hybrid vehicle 100 travels again in a city area or the like, the predicted engine output decreases. Thus, the heat generation of the engine 13 also decreases, and the target coolant temperature is also changed to the high T L. At this time, the inflow valve V 1 is closed, and the coolant flows through the flow path P 1 that does not pass through the radiator 21.As shown in the drawing, the coolant is cooled excessively because the target coolant temperature is conventionally constant when, for example, the target coolant temperature is low in the time period after t=0 to t1 and t3. In addition, the target coolant temperature remains high although the coolant needs to be sufficiently cooled because the engine output increases in the time period from t=t 2 to t 3. Thus, the coolant cannot sufficiently cool the engine 13.On the other hand, the target coolant temperature is variable in the control of the VCU 1 according to this embodiment. Then, based on the position information of the hybrid vehicle 100 input from the navigation device 11, the traffic information related to the route to the destination, and the engine control information, a change in the running condition of the hybrid vehicle 100 is obtained, and an appropriate engine output is predicted according to the running condition.The change timing setting unit 34 may then set each timing of t=t 1, t 2, and t 3 illustrated in FIG. 6 as the change timing. The coolant temperature change control unit 35 then performs the control for changing the temperature of the coolant at the set change timing. Thus, the engine 13 is efficiently cooled and the practical fuel consumption of the hybrid vehicle 100 can be reduced.In the above-described VCU 1 according to the first embodiment, the target coolant temperature is determined based on the predicted engine output, and the coolant is cooled or heated such that the coolant temperature reaches the target coolant temperature. Since the target agent cooling temperature is variable in accordance with the predicted engine output, the coolant temperature is also variable. As a result, the coolant having a high coolant temperature circulates through the flow path, and the cooling loss of the engine 13 can be reduced when the predicted engine output is low. In addition, the coolant having a low coolant temperature circulates through the flow path, and knocking of the engine 13 can be suppressed when the predicted engine output is high. In either case, the fuel economy of the hybrid vehicle 100 can be improved by the control of the VCU 1.[Second Embodiment]Next, with reference to FIG. 7, a configuration example and an operation example of the VCU according to a second embodiment of the invention will be described.Cooling the coolant to the target coolant temperature takes a period of time. Thus, for example, it is desirable to start cooling the coolant before the engine 13 is actually applied with the high load if the engine output prediction unit 32 can predict in advance that the engine 13 of the hybrid vehicle 100 is applied with a high load.Thus, the change timing setting unit 34 sets the change timing for cooling the coolant to the coolant temperature determined by the target coolant temperature determining unit 33. The change timing to be set is before the engine 13 is actually applied with a high load.Thus, the coolant temperature change control unit 35 performs the control for changing the coolant temperature at the set change timing. At this time, the coolant temperature change control unit 35 controls the operations of the electric thermostat 22 and the electric water pump 23 in the coolant temperature change control unit 35 such that the coolant reaches the target coolant temperature.FIG. 7 is an explanatory diagram illustrating an example of a target coolant temperature determined based on a predicted vehicle speed and a predicted engine output. The changes in the predicted vehicle speed, the predicted engine output, and the target coolant temperature in FIG. 7 are similar to the changes in the respective pieces of information illustrated in FIG. 6, so that different points will be described.In this embodiment, the engine 13 is stopped in a specific period between t=t 2 and t 3. At this time, a period during which the engine 13 is stopped in which the target coolant temperature is set to be low is referred to as a cooling controllable period because the VCU 1 can cool the coolant. The engine 13 then operates before t=t 3 and the predicted engine output power increases.On the other hand, the engine 13 may be stopped in a specific period after t=t 3 although the target coolant temperature needs to be kept high. Since the VCU 1 cannot increase the temperature of the coolant in this case, a period during which the engine 13 is stopped in which the target coolant temperature is set to high is referred to as an uncontrolled temperature rise period. Thus, the change timing setting unit (change timing setting unit 34) sets, as the change timing, the timing earlier than the timing at which the output of the internal combustion engine (engine 13) is changed from the high output to the low output, when the internal combustion engine output prediction unit (engine output prediction unit 32) predicts that the time period during which the internal combustion engine (engine 13) stops is equal to or longer than the set time period after the output of the internal combustion engine (engine 13) is changed from the high output to the low output.For example, if the hybrid vehicle 100 travels in a city area or the like after t=t 3, the engine output decreases if the engine 13 stops for a set time or more. Thus, the change timing setting unit 34 performs the setting for advancing the change timing from t 3 to t 4 so that the coolant temperature changes rapidly to the target coolant temperature T L determined by the target coolant temperature determining unit 33. Thus, the coolant temperature changes rapidly to the target coolant temperature T L and the coolant temperature can be maintained high as the engine output decreases after t3. As a result, the engine 13 can be efficiently cooled.In the above-described VCU 1 according to the second embodiment, when it is predicted that the coolant temperature cannot be increased to the target coolant temperature for a set time or longer due to stoppage of the engine 13, control is executed such that the timing of increasing the coolant temperature is advanced from before the engine 13 is stopped. Since the coolant temperature is increased before the engine 13 is stopped, the coolant temperature becomes the target coolant temperature even in the non-controllable temperature rise time. Thus, the coolant having a high coolant temperature can be circulated to the engine 13 even when the predicted engine output is low in the non-controllable temperature rise time period.[Third Embodiment]Next, with reference to FIG. 8, a control example of the VCU according to a third embodiment of the invention will be described.For example, it takes seven minutes for the coolant temperature to reach the target coolant temperature. For this reason, the target coolant temperature determined by the VCU based on the average value of the predicted engine output power in the future prediction time period starting from the current time may not be appropriate. In this embodiment, a control example of the VCU executing the processing for determining an appropriate target coolant temperature will be described.FIG. 8 is a graph illustrating a relationship between predicted engine output and target coolant temperature in a prediction period. In graphs (1) and (3) of FIG. 8, the horizontal axis represents time t and the vertical axis represents predicted engine output power. In the graphs (2) and (4) of FIG. 8, the horizontal axis represents time t and the vertical axis represents target coolant temperature.If the engine output prediction unit 32 of the VCU 1 extends the time period for obtaining the predicted engine output, a false target coolant temperature may be determined due to an improper predicted engine output. For example, the predicted engine output power may be initially low as shown in graph (1) of FIG. 8, and the predicted engine output power may be high thereafter, or the predicted engine output power may be initially high as shown in graph (3) of FIG. 8, and the predicted engine output power may be low thereafter. Here, the predicted engine output obtained by the engine output prediction unit 32 in the long time t 13 has the same AVG value in both the graphs ( 1) and ( 3) of FIG. 8. Thus, the VCU 1 does not need to know how to change the target coolant temperature.Thus, the engine output prediction unit (engine output prediction unit 32) predicts, as the output of the engine (engine 13), an average value of the output of the engine (engine 13) obtained every time period shorter than the time period required for the coolant temperature to change to the target coolant temperature. For example, the engine output prediction unit 32 sets the time duration for obtaining the predicted engine output shorter than t 13. In the graph (1) of FIG. 8, it is assumed that the engine output prediction unit 32 first predicts the predicted engine output power to be low in the time period t 11 and predicts the predicted engine output power to be high in the time period t 12 after the time period t 11 has elapsed. In this case, as illustrated in the graph ( 2) of FIG. 8, the target coolant temperature determination unit 33 determines the high target coolant temperature T 2 in the time period t 11 because the predicted engine output is low, and determines the low target coolant temperature T 1 in the time period t 12 because the predicted engine output is high. Since the coolant is heated or cooled by the target coolant temperatures T 1 and T 2 determined in this manner, the coolant appropriate for the predicted engine output can be circulated to the engine 13.In addition, in the graph ( 3) of FIG. 8, it is assumed that the engine output prediction unit 32 predicts the predicted engine output power to be high first in the time period t 11 and predicts the predicted engine output power to be low in the time period t 12 after the time period t 11 has elapsed. In this case, as illustrated in the graph ( 4) of FIG. 8, the target coolant temperature determination unit 33 determines the low target coolant temperature T 1 in the time period t 11 because the predicted engine output is high, and determines the high target coolant temperature T 2 in the time period t 12 because the predicted engine output is low.In the control of the above-described VCU 1 according to the third embodiment, the target coolant temperature is determined based on the predicted engine output obtained in a short period of time. Then, the coolant is heated or cooled by the target coolant temperatures thus determined, and the coolant appropriate for the predicted engine output may be circulated to the engine 13.Here, the time period for predicting the predicted engine output may be arbitrarily set. However, a processing load is applied to the VCU 1 if a time period for the engine output prediction unit 32 for predicting the predicted engine output is slightly increased. Thus, for example, the amount of time to predict the predicted engine output may be about half the amount of time required for the coolant to reach the target coolant temperature.[Fourth Embodiment]Next, referring to FIGS. 9 and 10, a cooling system according to a fourth embodiment of the invention will be described. In the cooling systems according to the first to third embodiments, it has been described that the electric thermostat 22 illustrated in FIG. 5 is configured. However, instead of the electric thermostat 22, a coolant control valve (MCV) that changes the flow rate of the coolant may be provided. The VCU 1 according to the first embodiment may be applied to any of the following embodiments.FIG. 9 is a system diagram illustrating a flow path of a coolant in a cooling system including an MCV 22A.The coolant temperature changing unit, the operation of which is controlled by the coolant temperature changing control unit 35 according to the fourth embodiment, includes a coolant merging unit (MCV 22A) and a variable flow rate unit (electric water pump 23).The coolant merging unit (MCV 22A) is provided so as to be capable of drawing the coolant into a merging portion of a first flow path (flow path P 1) through which the coolant circulates in the internal combustion engine (engine 13) and a second flow path (flow path P 2) through which the coolant circulates in the internal combustion engine (engine 13) and the radiator (radiator 21), and opens a valve (the inflow valves V 11 and V 12) so that the coolant can flow in at least one of the first flow path (flow path P 1) and the second flow path (flow path P 2), and merges and accepts the coolant.The variable flow rate unit (electric water pump 23) varies the flow rate of the coolant sucked into the coolant joining unit (MCV 22A), and circulates the coolant on the first flow path (flow path P 1) and / or on the second flow path (flow path P 2).For example, the MCV 22A includes two inflow valves V 11 and V 12 into which the coolant flows from the cylinder head 25 and the radiator 21, respectively, and one outflow valve V 10 from which the coolant flows from the electric water pump 23. The MCV 22A opens and closes the inflow valves V 11 and V 12 and the outflow valve V 10 according to the control of the VCU 1. That is, the coolant temperature change control unit 35 illustrated in FIGS. 3 and 4 can change the valve opening degrees of the two inflow valves V 11 and V 12 by controlling the operation of the MCV 22A. When the inflow valve V 12 of the MCV 22A is opened, the coolant flows through the flow paths P 0 and P 2. When the inflow valve V 11 of the MCV 22A is opened, the coolant flows through the flow path P 1.FIG. 10 is a graph illustrating a relationship between the valve opening degree of each of the inflow valves V 11 and V 12 of the MCV 22A and the flow rate of the electric water pump 23 with respect to the engine load in the prediction period.The coolant temperature change control unit (coolant temperature change control unit 35) operates the coolant merging unit (MCV 22A) such that the coolant flowing in from the first flow path (flow path P 1) is more than the coolant flowing in from the second flow path (flow path P 2) because the predicted output of the internal combustion engine (engine 13) is lower, and decreases the flow rate of the coolant flowing out from the variable flow rate unit (electric water pump 23). Alternatively, the coolant temperature change control unit (coolant temperature change control unit 35) operates the coolant merging unit (MCV 22A) such that the coolant flowing in from the first flow path (flow path P 1) is less than the coolant flowing in from the second flow path (flow path P 2) because the predicted output of the internal combustion engine (engine 13) is higher, and increases the flow rate of the coolant flowing out from the variable flow rate unit (electric water pump 23).In the graph ( 1) of FIG. 10, the horizontal axis represents the engine load in the prediction period, and the vertical axis represents the valve opening degree of each inflow valve of the MCV 22A. When the engine load is low in the prediction period, i.e., the engine output of the engine 13, the coolant temperature change control unit 35 narrows the opening degree of the inflow valve V 12 of the MCV 22A so that the coolant flowing from the radiator 21 into the MCV 22A is small. On the other hand, the coolant temperature change control unit 35 increases the amount of coolant flowing from the engine 13 into the MCV 22A to increase the opening degree of the inflow valve V 11 into which the coolant flows from the engine 13 of the MCV 22A, i.e., from the cylinder head 25. That is, when the engine output of the engine 13 is low, the coolant is not cooled excessively.As the engine load increases, the coolant temperature change control unit 35 expands the opening degree of the inflow valve V 12 into which the coolant from the radiator 21 flows, and inversely narrows the opening degree of the inflow valve V 11 into which the coolant from the engine 13 flows. That is, at a high engine load, the coolant flowing through the radiator 21 and passing through the MCV 22A increases, and the coolant flowing over the radiator 21 is sufficiently cooled and circulated as shown on the flow path P 2 of FIG. 3.In the graph ( 2) of FIG. 10, the horizontal axis represents the engine load in the prediction period and the vertical axis represents the flow rate of the electric water pump 23. the graph ( 2) of FIG. 10 is similar to the graph ( 2) illustrated in FIG. 5. That is, when the engine load is low in the prediction period, i.e., the engine output of the engine 13, the flow rate of the coolant circulating through the flow path P 1 illustrated in FIG. 9 increases, and when the engine load is high, the flow rate of the coolant flowing through the flow path P 2 increases. Thus, the coolant can sufficiently cool the engine 13 including the cylinder block 24 and the cylinder head 25.In the above-described VCU 1 according to the fourth embodiment, the valve opening degrees of the inflow valves V 11 and V 12 into which the coolant flows are changed by the MCV 22A controlled by the coolant temperature change control unit 35. When the load of the engine 13 is low, the VCU 1 narrows the inflow valve V 12 of the radiator 21, opens the inflow valve V 11 of the engine 13, and further decreases the flow rate of the electric water pump 23, thereby easily heating the coolant. On the other hand, when the load on the engine 13 is high, the VCU 1 opens the inflow valve V 12 of the radiator 21, narrows the inflow valve V 11 of the engine 13, and further increases the flow rate of the electric water pump 23, so that the engine 13 can be easily cooled with the coolant.[Fifth Embodiment]Next, referring to FIGS. 11 and 12, a cooling system according to a fifth embodiment of the invention will be described. The cooling system according to this embodiment is different from the cooling system according to the fourth embodiment in that a heater capable of heating the coolant even while the engine 13 is stopped is provided.FIG. 11 is a system diagram illustrating the flow path of the coolant in the cooling system including a heater 27.The coolant temperature changing unit, the operation of which is controlled by the coolant temperature changing control unit 35 according to the fifth embodiment, includes a heater (heater 27) that heats the coolant, a coolant merging unit (MCV 22B), and a variable flow rate unit (electric water pump 23).The heater 27 may heat the coolant flowing out of the water outlet 26.The coolant merging unit (MCV 22B) is provided so as to be capable of drawing the coolant into a merging portion of a first flow path (flow path P 1) through which the coolant circulates in the internal combustion engine (engine 13), a second flow path (flow path P 2) through which the coolant circulates in the internal combustion engine (engine 13) and the radiator (radiator 21), and a third flow path (flow path P 3) through which the coolant circulates in the heater (heater 27), and opens a valve (the inflow valves V 11, V 12, and V 13) so as to open, allowing the coolant to flow in from the first flow path (flow path P 1) and / or from the second flow path (flow path P 2) and / or from the third flow path (flow path P 3), and merging and receiving the coolant.The variable flow rate unit (electric water pump 23) varies the flow rate of the coolant sucked into the coolant joining unit (MCV 22B), and circulates the coolant on the first flow path (flow path P 1) and / or on the second flow path (flow path P 2) and / or on the third flow path (flow path P 3).For example, the MCV 22B includes three inflow valves V 11, V 12, and V 13 into which the coolant flows in this order from the radiator 21, the cylinder head 25, and the heater 27, and the outflow valve V 10 from which the coolant flows out to the electric water pump 23. Thus, the coolant temperature change control unit 35 controls the operation of the MCV 22B according to the stop or operation of the engine 13 to change the valve opening degrees of the three inflow valves V 11, V 12, and V 13 such that the temperature of the coolant changes to the target coolant temperature.The normal flow path P 0 includes, in addition to a flow path from the water outlet 26 toward the radiator 21, a flow path from the water outlet 26 toward the heater 27, and the flow path P 3 into which the coolant heated by the heater 27 flows is shown from the heater 27 to the MCV 22B. Whether the coolant that has passed through the radiator 27 flows into the MCV 22B depends on the control of the coolant temperature change control unit 35. That is, in a state where the inflow valves V 12 and V 13 of the MCV 22B are closed, the coolant does not flow through the flow paths P 2 and P 3, and thus the coolant remains on the normal flow path P 0.FIG. 12 is a graph illustrating an example of a change in the valve opening degree of each of the inflow valves V 11, V 12, and V 13 with respect to the temperature of the coolant.The coolant temperature change control unit (coolant temperature change control unit 35) operates the coolant merging unit (MCV 22B) such that the coolant flowing in from the second flow path (flow path P 2) is more than the coolant flowing in from the first flow path and from the third flow path (flow paths P 1 and P 3) when the internal combustion engine (engine 13) is stopped and the target coolant temperature is controlled to decrease it, or operates the coolant merging unit (MCV 22B) such that the coolant flowing in from the third flow path (flow path P 3) is more than the coolant flowing in from the first and second flow paths (flow paths P 1 and P 2) when the target coolant temperature is controlled to increase it. Further, the coolant temperature change control unit (coolant temperature change control unit 35) operates the coolant merging unit (MCV 22B) such that the coolant flowing in from the second flow path (flow path P 2) is more than the coolant flowing in from the first flow path and from the third flow path (flow paths P 1 and P 3) when the internal combustion engine (engine 13) operates and the target coolant temperature is controlled to decrease it, or operates the coolant merging unit (MCV 22B) such that the coolant flowing in from the first flow path (flow path P 1) is more than the coolant flowing in from the second and third flow paths (flow paths P 2 and P 3) when the target coolant temperature is controlled to increase it.The graph ( 1) of FIG. 12 shows a change in the valve opening degree of the MCV 22B when the engine 13 is stopped. In the graph (1), the horizontal axis represents the target coolant temperature, and the vertical axis represents the valve opening degree of each inflow valve of the MCV 22B. When the target coolant temperature is determined to be low (decreased), the coolant temperature change control unit 35 increases the valve opening degree of the inflow valve V 12 (abbreviated as "radiator inflow valve") into which the coolant flows from the radiator 21 so that the coolant flows to the radiator 21. Conversely, the coolant flowing over the engine 13 and the heater 27 may be low. Thus, the coolant temperature change control unit 35 narrows the valve opening degree of the inflow valve V 11 (abbreviated as "engine inflow valve") into which the coolant from the engine 13 flows and the inflow valve V 13 (abbreviated as "heater inflow valve") into which the coolant from the heater 27 flows.On the other hand, when the target coolant temperature is determined to be high (increased), the coolant temperature change control unit 35 increases the valve opening degree of the heater supply valve such that the coolant flows to the heater 27 to be heated. Thus, the temperature of the coolant heated by the heater 27 rapidly reaches the target coolant temperature. Since the amount of coolant flowing through the engine 13 and the radiator 21 may be inversely small, the coolant temperature change control unit 35 narrows the valve opening degree of the radiator inflow valve and the engine inflow valve. Thus, it is possible to prevent the coolant from circulating over the radiator 21 and being cooled too much.The graph ( 2) of FIG. 12 illustrates a change in the valve opening degree of the MCV 22B during the operation of the engine 13. In addition, in the graph (2), the horizontal axis represents the target coolant temperature, and the vertical axis represents the valve opening degree of the MCV 22B. When the target coolant temperature is determined to be low (decreased), the valve opening degree of the radiator inflow valve is expanded in the graph ( 2) of FIG. 12 as in the graph ( 1) of FIG. 12.On the other hand, when the target coolant temperature is determined to be high (increased), the coolant temperature change control unit 35 increases the valve opening degree of the engine inflow valve so that the coolant flows to the engine 13 to be heated. Thus, the coolant is heated by the engine 13, and the temperature of the coolant rapidly reaches the target coolant temperature. Conversely, the radiator 21 is used to cool the coolant, and the heater 27 has an insufficient amount of heat to raise the temperature of the coolant. Thus, the coolant temperature change control unit 35 narrows the valve opening degrees of the radiator inflow valve and the heater inflow valve because the amount of coolant flowing through the radiator 21 and the heater 27 may be small. Thus, the coolant can be heated by the amount of heat generated by the engine 13.In the above-described VCU 1 according to the fifth embodiment, the coolant temperature change control unit 35 changes the valve opening degrees of the inflow valves V 11, V 12, and V 13 opened by the MCV 22B depending on whether the engine 13 is stopped or operating. When the target coolant temperature decreases, the radiator inflow valve is opened and the coolant flowing into the radiator 21 is cooled regardless of whether the engine 13 is stopped or in operation. On the other hand, when the target coolant temperature rises when the engine 13 is stopped, the heater supply valve is opened to heat the coolant flowing into the heater 27. For example, the coolant heated by the heater 27 circulates through the engine 13, so that the engine 13 can be easily started when the temperature falls in winter or the like.When the target coolant temperature rises during the operation of the engine 13, the coolant temperature change control unit 35 expands the engine supply valve to heat the coolant flowing into the engine 13. Thus, the time period until the temperature of the coolant reaches the target coolant temperature can be shortened.[Sixth Embodiment]Next, a cooling system according to a sixth embodiment of the invention will be described. In the cooling system according to this embodiment, the engine 13 is cooled in accordance with the load of the engine 13 by cooling the engine piston with oil (coolant) injected through the oil nozzle.FIG. 13 is a cross-sectional view illustrating an example of an internal combustion engine to which an engine oil nozzle is applied.The cylinder block 24 and the cylinder head 25 illustrated in FIG. 3 are provided inside an internal combustion engine illustrated as the engine 13. In FIG. 13, the cylinder head 25 is not illustrated.The coolant temperature changing unit, the operation of which is controlled by the coolant temperature changing control unit 35, includes a coolant injection unit (oil nozzle 53) that injects the coolant to the piston (piston 42) of the internal combustion engine (engine 13), and a variable coolant supply unit (variable oil pump 57) that varies the flow rate of the coolant injected by the coolant injection unit (oil nozzle 53).A cylindrical cylinder liner 41 is provided inside the cylinder block 24, and a piston 42 is disposed inside the cylinder liner 41 so as to be capable of reciprocating. The cylinder liner 41 is provided with a water jacket 43 through which the coolant flows.The piston 42 is cast in a bottomed cylinder shape using a metal material such as aluminum alloy or cast iron.In an upper piston portion 46 having a piston bottom surface 45 facing a combustion chamber 44 formed above the piston 42, a plurality of annular grooves 47 are recessed over the entire circumference in the circumferential direction. In each annular groove 47, a piston ring (not shown) is fixed, and this piston ring seals a clearance with the inner surface of the cylinder liner 41 and wipes engine oil adhering to the inner surface of the cylinder liner 41. Below the piston 42 a cylindrical piston skirt 48 is provided which extends downwards in a thrust / anti-thrust direction orthogonal to a piston pin 51, wherein tilting of the piston is prevented by a piston skirt 48.The pin boss portion of the piston 42 and the upper end of the connecting rod 50 are relatively rotatably connected by a piston pin 51 inserted therethrough, and the lower end of the connecting rod 50 is rotatably fixed to the crank pin 52 of the crankshaft. Thus, the pressure (load) of the combustion gas ignited in the combustion chamber 44 facing the piston bottom surface 45 is transmitted to the crank pin 52 of the crankshaft via the piston pin 51 and the connecting rod 50.The oil nozzle 53 as a cooling device for an engine piston is fixed to the cylinder block 24. The oil nozzle 53 has a function of cooling the piston 42 by injecting and supplying engine oil toward the rear surface side of the piston 42. The oil nozzle 53 is fastened and fixed to a fastening surface 54 at the lower end of the cylinder liner 41 using a fastening bolt 55 to avoid interference with the connecting rod 50, the crankshaft, and the like. The flow rate of the oil sprayed through the oil nozzle 53 is changed by the variable displacement oil pump 57 connected to the oil nozzle 53.The cylinder block 24 is provided with an oil supply passage 56 for supplying engine oil to an oil supply portion including the oil nozzle 53. Although not illustrated, the engine oil stored in an oil pan provided under the internal combustion engine is pressurized by an oil pump and supplied to a lubrication portion, a hydraulic operating device, and the like via the oil supply passage 56 in addition to the oil nozzle 53.Typical structures of the oil nozzle 53 include a die casting type, a 2-part brazed type, and an integration brazed type. In the case of the die casting type and the brazed 2-split type, the oil nozzle 53 is usually fixed and fixed to the cylinder block 24 by a fixing bolt including a lock ball. When a valve mechanism is incorporated in the brazed integration type, the oil nozzle 53 is fixed to the cylinder block side by a general fastening bolt that does not include a lock ball.The lock ball is biased by a spring in a direction of closing the oil supply passage 56, wherein the engine oil is supplied to the oil nozzle 53 when the hydraulic pressure of the engine oil in the oil supply passage 56 (main speed) exceeds a set load of the spring. That is, the oil nozzle 53 is configured such that the engine oil is spontaneously injected when the oil pressure of the engine oil supplied to the oil supply passage 56 of the internal combustion engine becomes equal to or higher than a predetermined pressure. The engine oil flowing into the oil nozzle 53 is injected to the rear surface side of the piston bottom surface 45 through a piping inside the oil nozzle 53. Thus, the engine oil is used as an example of coolant for cooling the piston 42.FIG. 14 is a graph illustrating the relationship between the flow rate of the oil nozzle 53 and the engine load in the prediction period.While the predicted output of the internal combustion engine (engine 13) is lower, the coolant temperature change control unit (coolant temperature change control unit 35) operates the variable coolant supply unit (variable oil pump 57) such that the coolant injection unit (oil nozzle 53) injects the coolant (oil) at a smaller flow rate, or while the predicted output of the internal combustion engine (engine 13) is higher, operates the variable coolant supply unit (variable oil pump 57) such that the coolant injection unit (oil nozzle 53) injects the coolant (oil) at a larger flow rate.In the graph of FIG. 14, the horizontal axis represents the engine load in the prediction period and the vertical axis represents the flow rate of the oil nozzle 53. When the engine load in the prediction period, i.e., the engine output of the engine 13, is low, the flow rate of the oil nozzle 53 can be decreased because the amount of heat of the cylinder block 24 is also small. On the other hand, it is necessary to cool the cylinder block 24 because the amount of heat of the cylinder block 24 increases as the engine output of the engine 13 increases. Here, in each of the above-described embodiments, the engine 13 is cooled by causing the coolant to flow to the engine 13, but in this embodiment, cooling of the engine 13 is promoted by further increasing the flow rate of the oil nozzle 53. Thus, the engine 13 is efficiently cooled by the coolant and the oil nozzle.In the above-described cooling system according to the sixth embodiment, the VCU 1 controls the variable oil pump 57 to change the flow rate of the oil jet 53 injected through the oil nozzle 53, thereby cooling the cylinder block 24. At the same time, since the oil jet cools the cylinder block 24 together with the coolant, the temperature of the coolant easily reaches the target coolant temperature and the coolant can efficiently cool the engine 13 including the cylinder block 24.[Changes]Note that the hybrid vehicle 100 to which the VCU 1 according to each of the above-described embodiments is mounted is a series hybrid vehicle, but various forms of hybrid vehicles such as a parallel hybrid vehicle and a plug-in hybrid vehicle may be used. Further, the VCU 1 is not limited to the hybrid vehicle 100, and may be mounted on a vehicle including only an engine.In addition, in each of the above-described embodiments, masking can be performed without performing the processing of changing the target coolant temperature. For example, it may become difficult to predict the output power of the engine 13 when the holding time of the hybrid vehicle 100 becomes long. Thus, the engine output prediction unit (engine output prediction unit 32) notifies the target coolant temperature determination unit (target coolant temperature determination unit 33) that the output of the engine (engine 13) cannot be predicted when the time period during which the vehicle (hybrid vehicle 100) stops is a predetermined time period or longer. When the target coolant temperature determination unit (target coolant temperature determination unit 33) is notified that the output of the internal combustion engine (engine 13) cannot be predicted, the target coolant temperature determination unit sets the target coolant temperature to a predetermined value. As a result, for example, the operation of the coolant temperature changing unit is controlled such that the coolant temperature becomes the target coolant temperature set to 80 degrees. When the hybrid vehicle 100 starts to move thereafter, the process of changing the target coolant temperature may be resumed in each embodiment.Further, the navigation device 11 has been described as being mounted on the hybrid vehicle 100, but a navigation function of a mobile terminal (not shown) that can be carried by a driver or a passenger of the vehicle may be used. The VCU 1 may then execute the prediction of the engine output, the determination of the target coolant temperature, and the control for setting the coolant temperature to the target coolant temperature based on the position information received from the mobile terminal and the map information including the route to the target.In addition, the invention is not limited to each embodiment described herein, and it goes without saying that various application examples and changes can be made without departing from the gist of the invention described in the claims.For example, the above embodiments have been described in detail for easy understanding of the invention, but are not necessarily limited to those including all the described configurations. In addition, some of the configurations of a certain embodiment may be replaced with the configurations of the other embodiments, and the configurations of the other embodiments may be added to the configurations of a certain embodiment. In addition, some of the configurations of each embodiment may be omitted, replaced with other configurations, and added to other configurations.Also, only control lines and information lines which are considered necessary for explanation are shown, but not all control lines and information lines for one product are shown. In practice, almost all configurations may be considered to be connected to each other.List of reference characters1 VCU 2 ECU 3 GCU 4 BCU 5 MCU 13 Engine 18 Motor 21 Radiator 22 Electric thermostat 23 Electric water pump 24 Cylinder block 25 Cylinder head 31 Engine output control unit 32 Engine output prediction unit 33 Target average temperature determination unit 34 Change timing setting unit 35 Coolant temperature change control unit 100 Hybrid vehicle

Claims

A control device mounted on a vehicle (100) including an internal combustion engine (13) as a drive source, the control device comprising: an engine output control unit (31) that outputs, to the internal combustion engine (13), engine control information for controlling an output of the internal combustion engine (13); an engine output prediction unit (32) that predicts an output of the internal combustion engine (13) in a future prediction period based on position information of the vehicle (100) acquired by a position determination unit that measures a position of the vehicle (100), traffic information related to a route to a destination, and the engine control information; a target coolant temperature determination unit (33) that determines a target coolant temperature that is a target temperature of coolant for cooling the internal combustion engine (13) based on the predicted output of the internal combustion engine (13); a change timing setting unit (34) that sets a change timing for changing a temperature of the coolant to the target coolant temperature based on the predicted output of the internal combustion engine (13); and a coolant temperature change control unit (35) that controls an operation of a coolant temperature change unit that changes a temperature of the coolant at the change timing based on the predicted output of the internal combustion engine (13) so as to reach the target coolant temperature, wherein the output of the internal combustion engine (13) is changed in accordance with a load of the internal combustion engine (13) in the prediction time period, wherein the target coolant temperature determining unit (33) determines the target coolant temperature to be higher while the predicted output of the internal combustion engine (13) is lower and determines the target coolant temperature to be lower while the predicted output of the internal combustion engine (13) is higher, and wherein the change timing setting unit (34) sets a timing at which the predicted output of the internal combustion engine (13) is changed from a low output to a high output or a timing at which the predicted output of the internal combustion engine (13) is changed from a high output to a low output as the change timing, wherein the change timing setting unit (34) sets a timing earlier than a timing, in which the output of the engine (13) is changed from a high output to a low output as the change timing when it is predicted by the engine output prediction unit (32) that a time period during which the engine (13) stops is equal to or longer than a set time period after the output of the engine (13) is changed from a high output to a low output.The control device according to claim 1, wherein the engine output prediction unit (32) predicts a maximum value of the output of the engine (13) in the prediction period as the output of the engine (13).The control device according to claim 1, wherein the engine output prediction unit (32) predicts an average value of the output of the engine (13) obtained in each time period shorter than a time period required for changing the target coolant temperature in the prediction time period as the output of the engine (13), and wherein the target coolant temperature determination unit (33) determines the target coolant temperature to be high when the average value is equal to or less than a set average value and determines the target coolant temperature to be low when the average value exceeds the set average value.The control device according to claim 1, wherein the engine output prediction unit (32) predicts an output of the engine (13) in the prediction period based on a vehicle speed of the vehicle (100), and wherein the vehicle speed when the vehicle (100) travels on a highway is higher than a value when the vehicle (100) travels in a city area.The control device according to claim 1, wherein the coolant temperature changing unit includes a coolant merging unit (22) provided so as to be capable of drawing the coolant into a merging portion of a first flow path (P1) through which the coolant circulates in the internal combustion engine (13) and a second flow path (P2) through which the coolant circulates in the internal combustion engine (13) and a radiator (21), opening a valve (V1) in accordance with a temperature of the coolant to allow the coolant to flow in from the second flow path (P2), merging and drawing the coolant, and a variable flow rate unit (23), varying a flow rate of the refrigerant drawn into the refrigerant merging unit (22) and circulating the refrigerant on the first flow path (P1) or the second flow path (P2).The control device according to claim 5, wherein the coolant temperature change control unit (35) operates the coolant merging unit (22) at a higher coolant temperature while the predicted output of the internal combustion engine (13) is lower to circulate the coolant to the first flow path (P1) and reduces the flow rate of the coolant flowing out from the variable flow rate unit, or operates the coolant merging unit (22) at a lower coolant temperature while the predicted output of the internal combustion engine (13) is higher to circulate the coolant to the second flow path (P2) and increases the flow rate of the coolant flowing out from the variable flow rate unit.The control device according to claim 1, wherein the coolant temperature changing unit includes a coolant merging unit (22A) provided so as to be capable of drawing the coolant into a merging portion of a first flow path (P1) through which the coolant circulates in the internal combustion engine (13) and a second flow path (P2) through which the coolant circulates in the internal combustion engine (13) and in a radiator (21), opening a valve (V11, V12) for allowing the coolant to flow in from the first flow path (P1) and / or from the second flow path (P2), and merging and drawing the coolant; and a variable flow rate unit (23) that varies a flow rate of the refrigerant sucked into the refrigerant merging unit (22A) and circulates the refrigerant on the first flow path (P1) and / or on the second flow path (P2).The control device according to claim 7, wherein the coolant temperature change control unit (35) operates the coolant merging unit (22A) such that the coolant flowing in from the first flow path (P1) becomes more than the coolant flowing in from the second flow path (P2) while the predicted output of the internal combustion engine (13) is lower, and wherein the coolant temperature change control unit (35) decreases the flow rate of the coolant flowing out from the variable flow rate unit or operates the coolant merging unit (22A) such that the coolant flowing in from the first flow path (P1) becomes less than the coolant flowing in from the second flow path (P2) while the predicted output of the internal combustion engine (13) is higher, and increases the flow rate of the refrigerant flowing out from the variable flow rate unit (23).The control device according to claim 1, wherein the coolant temperature changing unit includes: a heater (27) that heats the coolant; a coolant merging unit (22B) provided so as to be capable of drawing the coolant to a merging portion of a first flow path (P1) through which the coolant circulates in the internal combustion engine (13), a second flow path (P2) through which the coolant circulates in the internal combustion engine (13) and in a radiator (21), and a third flow path (P3) through which the coolant circulates in the heater (27), opening a valve (V11, V12, V13) to enable, that the coolant flows in from the first flow path (P 1) and / or from the second flow path (P 2) and / or from the third flow path (P 3) and merges and draws the coolant, and a variable flow rate unit (23) that varies the flow rate of the coolant drawn into the coolant merging unit (22B) and circulates the coolant on the first flow path (P 1) and / or on the second flow path (P 2) and / or on the third flow path (P 3).The control device according to claim 9, wherein the coolant temperature change control unit (35) performs control to operate the coolant merging unit (22B) such that the coolant flowing in from the second flow path (P2) is more than the coolant flowing in from the first flow path (P1) and from the third flow path (P3) when the internal combustion engine (13) is stopped and when the target coolant temperature is controlled to decrease, or to operate the coolant merging unit (22B) such that the coolant flowing in from the third flow path (P3) is more than the coolant flowing in from the first flow path (P1) and from the second flow path (P2) when the target coolant temperature is controlled to increase, or wherein the coolant temperature change control unit (35) operates the coolant connection unit such that the coolant flowing in from the second flow path (P 2) is more than the coolant flowing in from the first flow path (P 1) and from the third flow path (P 3) when the internal combustion engine (13) operates and when the target coolant temperature is controlled to decrease, or operates the coolant merging unit (22B) such that the coolant flowing in from the first flow path (P 1) is more than the coolant flowing in from the second flow path (P 2) and from the third flow path (P 3) when the target coolant temperature is controlled to increase.The control device according to claim 1, wherein the coolant temperature changing unit includes: a coolant injection unit (53) that injects the coolant to a piston (42) of the internal combustion engine (13); and an adjustable coolant supply unit (57) that varies a flow rate of the coolant injected by the coolant injection unit (53), wherein the coolant temperature changing control unit (35) operates the adjustable coolant supply unit (57) such that the coolant injection unit (53) injects the coolant at a lower flow rate while the predicted output of the internal combustion engine (13) is lower, or operates the adjustable coolant supply unit (57) such that the coolant injection unit (53) injects the coolant at a higher flow rate while the predicted output of the internal combustion engine (13) is higher.A control device mounted on a vehicle (100) including an internal combustion engine (13) as a drive source, the control device comprising: an engine output control unit (31) that outputs, to the internal combustion engine (13), engine control information for controlling an output of the internal combustion engine (13); an engine output prediction unit (32) that predicts an output of the internal combustion engine (13) in a future prediction period based on position information of the vehicle (100) acquired by a position determination unit that measures a position of the vehicle (100), traffic information related to a route to a destination, and the engine control information; a target coolant temperature determination unit (33) that determines a target coolant temperature that is a target temperature of coolant for cooling the internal combustion engine (13) based on the predicted output of the internal combustion engine (13); a change timing setting unit (34) that sets a change timing for changing a temperature of the coolant to the target coolant temperature based on the predicted output of the internal combustion engine (13); A coolant temperature change control unit (35) that controls an operation of a coolant temperature change unit that changes a temperature of the coolant at the time of change based on the predicted output of the internal combustion engine (13) so as to reach the target coolant temperature, wherein the internal combustion engine output prediction unit (32) notifies the target coolant temperature determination unit (33) that an output of the internal combustion engine (13) cannot be predicted when a time period during which the vehicle (100) stops is equal to or longer than a predetermined time period, and wherein the target coolant temperature determination unit (33) sets the target coolant temperature to a predetermined value when it is notified that the output of the internal combustion engine (13) cannot be predicted.The control device according to any one of claims 1 to 12, wherein the vehicle (100) travels through an output of the internal combustion engine (13) and / or an electric drive unit (18).

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