Vehicle control device

Abstract

The present invention provides a vehicle control device comprising a control device that controls a refrigerant pump installed in a vehicle. The vehicle comprises: heat-generating equipment that generates heat through travel; heat-dissipating equipment that dissipates heat generated by the heat-generating equipment; and a refrigerant pump that delivers, to the heat-dissipating equipment, a refrigerant that has absorbed heat generated by the heat-generating equipment. The control device: computes the current heat dissipation of the heat-dissipating equipment; computes the maximum heat dissipation of the heat-dissipating equipment given the current operating conditions; computes a heat-dissipating capacity margin based on the difference between the heat dissipation and the maximum heat dissipation; computes the current heat generation of the heat-generating equipment; computes the maximum heat generation of the heat-generating equipment; computes a heat-generating capacity potential based on the difference between the heat generation and the maximum heat generation; and controls the rotational speed of the refrigerant pump according to a permissible temperature margin, which is the difference between the heat-dissipating capacity margin and the heat-generating capacity potential.

Description

Vehicle control device

[0001] The present invention relates to a vehicle control device.

[0002] In electric vehicles, thermal circuits are used to manage the temperatures of the traction motor and battery to protect the equipment and maintain performance. Coolant circulates through the thermal circuit, and this coolant cools various equipment. The heat stored in the coolant in the thermal circuit is released into the atmosphere by a radiator installed in the thermal circuit. The amount of heat released into the atmosphere is controlled by the flow rate of the coolant flowing through the thermal circuit. An electric water pump is used to control the flow rate of the coolant. As the coolant temperature rises and the motor torque increases, the amount of coolant discharged by the electric water pump is increased, increasing the heat dissipation by the radiator and preventing the temperature of the equipment from rising excessively.

[0003] When the load on the motor increases, such as when the vehicle accelerates or travels uphill, the amount of heat generated by the motor increases. In such cases, the rotation speed of the electric water pump is increased based on the increase in heat generated, detected by a temperature sensor in the thermal circuit, to increase the amount of coolant discharged, thereby preventing battery deterioration and protecting the various components and maintaining performance.

[0004] Patent Literature 1 discloses an autonomous driving system that predicts the temperature of a drive motor during autonomous driving based on information about the route traveled during autonomous driving. The temperature of the drive motor is predicted based on the amount of heat generated by the drive motor, which is based on the required braking / driving torque of the drive motor during autonomous driving, the amount of heat dissipated by the drive motor, which is based on various conditions such as the cooling performance of the drive motor, outside air temperature, and driving wind, and the current temperature of the drive motor. If it is determined that the predicted drive motor temperature will be equal to or higher than a predetermined threshold, the route is replanned to prevent the temperature of the drive motor from rising.

[0005] Japanese Patent Application Laid-Open No. 2021-110574

[0006] However, in the technology described in Patent Document 1, a target speed is obtained based on the gradient and distance of each section of a candidate route, and braking / driving torque is calculated to achieve that target speed. Therefore, depending on the actual road environment, such as traffic congestion, the vehicle may not be able to travel at the target speed. In such cases, the temperature of the drive motor may deviate from the predicted value, and the drive motor may not be cooled properly or may be overcooled.

[0007] An object of the present invention is to provide a vehicle control device that can control a water pump in accordance with the running state of a vehicle and prevent insufficient or excessive cooling from occurring.

[0008] A vehicle control device according to one aspect of the present invention is a vehicle control device including a control device for controlling a refrigerant pump mounted on a vehicle, the vehicle including a heat-generating device that generates heat while the vehicle is running, a heat-dissipating device that dissipates the heat generated by the heat-generating device, and the refrigerant pump that sends refrigerant that has absorbed the heat generated by the heat-generating device to the heat-dissipating device, wherein the control device calculates a current heat dissipation amount of the heat-dissipating device, calculates a maximum heat dissipation amount of the heat-dissipating device under current operating conditions, calculates a heat dissipation capacity margin based on a difference between the heat dissipation amount and the maximum heat dissipation amount, calculates the current heat generation amount of the heat-generating device, calculates a maximum heat generation amount of the heat-generating device, calculates a heat generation capacity potential based on the difference between the heat generation amount and the maximum heat generation amount, and controls a rotation speed of the refrigerant pump in accordance with an allowable temperature margin that is the difference between the heat dissipation capacity margin and the heat generation capacity potential.

[0009] According to the present invention, it is possible to prevent insufficient or excessive cooling by the refrigerant pump depending on the running state of the vehicle.

[0010] FIG. 1 is a block diagram showing the main configuration of a vehicle control device. FIG. 2 is a block diagram showing the hardware configuration of a control system of the vehicle control device. FIG. 3 is a diagram showing an example of target rotation speed information. FIG. 4A is a timing chart showing the relationship between vehicle speed and time. FIG. 4B is a timing chart showing the relationship between outside air temperature and time. FIG. 4C is a timing chart showing the relationship between the temperature of coolant at the outlet side of the radiator and time. FIG. 4D is a timing chart showing the relationship between the temperature of coolant at the outlet side of the battery and time. FIG. 4E is a timing chart showing the relationship between the open / closed state of a grille shutter and time. FIG. 5A is a timing chart showing the relationship between the rotation speed of a cooling fan provided in the radiator and time. FIG. 5B is a timing chart showing the relationship between the rotation speed of a compressor and time. FIG. 5C is a timing chart showing the relationship between the rotation speed of a refrigerant pump and time. FIG. 5D is a timing chart showing the relationship between a torque estimation value calculated by a motor torque estimator and time. FIG. 6A is a timing chart showing the relationship between a calculated current heat dissipation amount and time. FIG. 6B is a timing chart showing the relationship between the calculated maximum heat dissipation amount and time. FIG. 6C is a timing chart showing the relationship between the calculated heat dissipation capacity margin and time. FIG. 7A is a timing chart showing the relationship between the calculated current heat dissipation amount and time. FIG. 7B is a timing chart showing the relationship between the calculated maximum heat dissipation amount and time. FIG. 7C is a timing chart showing the relationship between the calculated heat dissipation capacity potential and time. FIG. 7D is a timing chart showing the relationship between the calculated allowable temperature margin and time. FIG. 8 is a flowchart showing the flow of processing by the control device. FIG. 9A is a timing chart showing the relationship between the vehicle's climbing angle and time in the second embodiment. FIG. 9B is a timing chart showing the relationship between the vehicle's altitude and time in the second embodiment. FIG. 9C is a timing chart showing the relationship between the vehicle speed and time in the second embodiment. FIG. 9D is a timing chart showing the relationship between the outside air temperature and time in the second embodiment. FIG. 9E is a timing chart showing the relationship between the coolant temperature at the outlet side of the radiator and time in the second embodiment.FIG. 10A is a timing chart showing the relationship between time and the rotation speed of a cooling fan provided in a radiator in the second embodiment. FIG. 10B is a timing chart showing the relationship between time and the rotation speed of a compressor in the second embodiment. FIG. 10C is a timing chart showing the relationship between time and the rotation speed of a refrigerant pump in the second embodiment. FIG. 10D is a timing chart showing the relationship between an estimated torque value and time in the second embodiment. FIG. 11A is a timing chart showing the relationship between time and the calculated current heat dissipation amount in the second embodiment. FIG. 11B is a timing chart showing the relationship between time and the calculated maximum heat dissipation amount in the second embodiment. FIG. 11C is a timing chart showing the relationship between time and the calculated heat dissipation capacity margin in the second embodiment. FIG. 12A is a timing chart showing the relationship between time and the calculated current heat dissipation amount in the second embodiment. FIG. 12B is a timing chart showing the relationship between time and the calculated maximum heat dissipation amount in the second embodiment. FIG. 12C is a timing chart showing the relationship between the calculated heat generation capacity potential and time in the second embodiment. FIG. 12D is a timing chart showing the relationship between the calculated allowable temperature margin and time in the second embodiment. FIG. 13A is a timing chart showing the relationship between the vehicle's climbing angle and time in the third embodiment. FIG. 13B is a timing chart showing the relationship between the vehicle's altitude and time in the third embodiment. FIG. 13C is a timing chart showing the relationship between the vehicle speed and time in the third embodiment. FIG. 13D is a timing chart showing the relationship between the outside air temperature and time in the third embodiment. FIG. 13E is a timing chart showing the relationship between the coolant temperature at the outlet side of the radiator 16 and time in the third embodiment. FIG. 14A is a timing chart showing the relationship between the rotation speed of a cooling fan provided in the radiator and time in the third embodiment. FIG. 14B is a timing chart showing the relationship between the compressor rotation speed and time in the third embodiment. FIG. 14C is a timing chart showing the relationship between the rotation speed of the refrigerant pump and time in the third embodiment.FIG. 14D is a timing chart showing the relationship between a torque estimation value and time in the third embodiment. FIG. 15A is a timing chart showing the relationship between a calculated current heat dissipation amount and time in the third embodiment. FIG. 15B is a timing chart showing the relationship between a calculated maximum heat dissipation amount and time in the third embodiment. FIG. 15C is a timing chart showing the relationship between a calculated heat dissipation capacity margin and time in the third embodiment. FIG. 16A is a timing chart showing the relationship between a calculated current heat dissipation amount and time in the third embodiment. FIG. 16B is a timing chart showing the relationship between a calculated maximum heat dissipation amount and time in the third embodiment. FIG. 16C is a timing chart showing the relationship between a calculated heat dissipation capacity potential and time in the third embodiment. FIG. 16D is a timing chart showing the relationship between a calculated allowable temperature margin and time in the third embodiment. FIG. 17 is a block diagram showing the configuration of a control system of the vehicle control device 1 in the fourth embodiment. FIG. 18A is a diagram showing the relationship between a target speed and a distance from a current position. FIG. 18B is a diagram showing the relationship between an altitude and a distance from a current position. FIG. 18C is a diagram showing the relationship between target torque and distance from the current position. FIG. 19A is a diagram showing the relationship between outside air temperature and distance from the current position. FIG. 19B is a diagram showing the relationship between coolant temperature and distance from the current position. FIG. 19C is a diagram showing the relationship between the open / close status of the grille shutter and distance from the current position. FIG. 19D is a diagram showing the relationship between the actual vehicle speed and distance from the current position. FIG. 20A is a diagram showing the relationship between the cooling fan rotation speed and distance from the current position. FIG. 20B is a diagram showing the relationship between the compressor rotation speed and distance from the current position. FIG. 20C is a diagram showing the relationship between the refrigerant pump rotation speed and distance from the current position. FIG. 20D is a diagram showing the relationship between a torque estimate calculated by the motor torque estimator and distance from the current position. FIG. 21A is a diagram showing the relationship between a calculated current heat dissipation amount and distance from the current position. FIG. 21B is a diagram showing the relationship between a calculated maximum heat dissipation amount and distance from the current position. FIG. 21C is a diagram showing the relationship between a calculated heat dissipation capacity margin and distance from the current position. FIG. 22A is a diagram showing the relationship between the calculated current heat generation amount and the distance from the current position.Fig. 22B is a diagram showing the relationship between the calculated maximum heat generation amount and the distance from the current position, Fig. 22C is a diagram showing the relationship between the calculated heat generation capacity potential and the distance from the current position, and Fig. 22D is a diagram showing the relationship between the calculated allowable temperature margin and the distance from the current position.

[0011] Hereinafter, a vehicle control device according to an embodiment of the present invention will be described with reference to the drawings. In all drawings for explaining this embodiment, blocks or elements having the same functions are denoted by the same reference numerals, and repeated description thereof will be omitted.

[0012] First Embodiment A vehicle control device 1 according to a first embodiment will be described with reference to FIGS. 1 to 8. FIG. 1 is a diagram schematically illustrating the configuration of a main part of the vehicle control device 1 mounted on a vehicle 10 according to the first embodiment. The vehicle control device 1 includes a thermal circuit 11, a refrigerant pump 12, a motor 13, a motor inverter 14, a battery 15, a radiator 16, a DC / DC converter 17, a heating-side heat exchanger 18, a cooling-side heat exchanger 19, and a charger 151. The refrigerant pump 12, the motor 13, the motor inverter 14, the battery 15, the radiator 16, the DC / DC converter 17, the heating-side heat exchanger 18, the cooling-side heat exchanger 19, and the charger 151 are connected by a coolant pipe 111 and thereby incorporated into the thermal circuit 11.

[0013] The vehicle 10 is an electric vehicle that drives the wheels with a motor 13. The motor 13 operates by receiving power from a battery 15. The driving of the motor 13 is controlled by a current generated by a motor inverter 14. The battery 15 is a high-voltage battery (e.g., 350 V) that supplies power to the motor 13. The battery 15 is charged with power supplied from a 200 V outlet and boosted by a charger 151. The charger 151 generates heat during boosting, and is therefore connected to a thermal circuit 11. In addition, a battery water temperature sensor 23 is provided downstream of the battery 15 in the coolant pipe 111, and the battery water temperature sensor 23 detects the temperature of the coolant downstream of the battery 15.

[0014] The DC / DC converter 17 reduces the voltage of the power stored in the battery 15 and charges the 12V battery 152. The 12V battery 152 is a battery that stores power for operating the auxiliary equipment. The DC / DC converter 17 generates heat when reducing the voltage, and is therefore connected to a thermal circuit 11.

[0015] The radiator 16 is a heat dissipation device that dissipates heat stored in the refrigerant (coolant) in the coolant pipe 111. The radiator 16 is provided with a cooling fan 161. When the temperature of the coolant is higher than the outside air temperature, the cooling fan 161 rotates, and the radiator 16 dissipates heat from the coolant to the outside air through heat exchange. A radiator water temperature sensor 22 is provided downstream of the coolant pipe 111 from the radiator 16, and the radiator water temperature sensor 22 detects the temperature of the coolant at the outlet side of the radiator 16.

[0016] Refrigerant pump 12 is provided upstream of thermal circuit 11 with respect to battery 15. Refrigerant pump 12 is an electric water pump that circulates coolant through coolant pipe 111. Refrigerant pump 12 is driven by rotation of water pump driver 28, and discharges coolant stored in reserve tank 122 into coolant pipe 111. The amount of coolant discharged by refrigerant pump 12 increases or decreases as the vehicle control device 1 controls the rotation speed of pump motor 121.

[0017] The heating-side heat exchanger 18 and the cooling-side heat exchanger 19 are mounted on the vehicle 10 and provided in an air-conditioning refrigerant circuit that utilizes the heat pump effect. The heating-side heat exchanger 18 exchanges heat with air-conditioning refrigerant that has been pressurized (compressed) by a compressor 181 and raised to a high temperature. The cooling-side heat exchanger 19 exchanges heat with air-conditioning refrigerant that has been expanded by an expansion valve or the like and lowered to a low temperature.

[0018] 2 is a block diagram showing the hardware configuration of the control system of the vehicle control device 1. The vehicle control device 1 includes a control device 100, a grille shutter open / close sensor 20, a fan rotation speed sensor 21, a radiator water temperature sensor 22, a battery water temperature sensor 23, a motor rotation speed sensor 24, an outside air temperature sensor 25, a compressor rotation speed sensor 26, a water pump rotation speed sensor 27, and a water pump driver 28.

[0019] As shown in FIG. 2 , the control device 100 is composed of a computer including an arithmetic unit 101, which is a processing device such as a CPU (Central Processing Unit), an MPU (Micro Processing Unit), or a DSP (Digital Signal Processor), a non-volatile memory 102 such as a ROM (Read Only Memory), a flash memory, or a hard disk drive, a volatile memory 103 called a RAM (Random Access Memory), an input interface 104, an output interface 105, and other peripheral circuits. Furthermore, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), etc. may also be used as the arithmetic unit 101, which is a processing unit. The nonvolatile memory 102 and the volatile memory 103 function as storage devices that store information (data).

[0020] The nonvolatile memory 102 stores programs capable of executing various calculations. In other words, the nonvolatile memory 102 is a storage device (storage medium) from which programs realizing the functions of this embodiment can be read. The arithmetic device 101 deploys the programs stored in the nonvolatile memory 102 into a volatile memory and executes the programs. The arithmetic device 101 performs predetermined calculations on signals received from the input interface 104, the output interface 105, and the storage devices, nonvolatile memory 102 and volatile memory 103, in accordance with the programs.

[0021] The input interface 104 converts signals input from the grille shutter open / close sensor 20, fan rotation speed sensor 21, radiator water temperature sensor 22, battery water temperature sensor 23, motor rotation speed sensor 24, outside air temperature sensor 25, compressor rotation speed sensor 26, and water pump rotation speed sensor 27 into signals that can be calculated by the arithmetic unit 101. The output interface 105 generates an output signal according to the calculation result of the arithmetic unit 101 and outputs the signal to the water pump driver 28. The calculations performed by the arithmetic unit 101 will be described in detail later.

[0022] The grille shutter sensor 20 detects the open / closed state of a grille shutter provided at the front of the vehicle 10. The grille shutter switches between an open state and a closed state. The grille shutter switches to the open state when the coolant temperature detected by a battery water temperature sensor 23 at the outlet side of the battery 15 is, for example, 10°C or higher. The grille shutter is closed, for example, during warm-up, to block outside air from flowing into the front portion of the vehicle 10. The grille shutter is open, for example, while the vehicle is moving, to allow outside air (wind from driving) to flow into the front portion of the vehicle 10, thereby contributing to cooling the radiator 16.

[0023] The fan rotation speed sensor 21 detects the rotation speed of the cooling fan 161 provided in the radiator 16. The fan rotation speed sensor 21 may be of various types, such as a mechanical type (contact type), an optical type, a magnetic type, or a magnetic induction type.

[0024] The motor rotation speed sensor 24 detects the rotation speed of the motor 13. The motor rotation speed sensor 24 may be any of various types of rotation speed sensors, such as a mechanical type (contact type), an optical type, a magnetic type, or a magnetic induction type.

[0025] The outside air temperature sensor 25 is a temperature sensor that detects the air temperature outside the vehicle 10. The compressor rotation speed sensor 26 detects the rotation speed of a rotor that constitutes the compressor 181 provided in the above-mentioned air conditioning refrigerant circuit. The water pump rotation speed sensor 27 detects the rotation speed of a rotor of a motor provided in the refrigerant pump 12. The rotation speed can be detected using various types of rotation speed sensors, such as mechanical (contact type), optical type, magnetic type, and magnetic induction type.

[0026] <Calculation device 101> The calculation device 101 has the following functions: a motor torque estimation unit 220, a coolant temperature estimation unit 221, a current heat dissipation amount calculation unit 222, a maximum heat dissipation amount calculation unit 223, a heat dissipation capacity margin calculation unit 224, an allowable temperature margin calculation unit 225, a current heat generation amount calculation unit 226, a maximum heat generation amount calculation unit 227, a heat generation capacity potential calculation unit 228, and a target pump rotation speed calculation unit 229.

[0027] The motor torque estimation unit 220 estimates (calculates) the torque actually generated by the motor 13 using a torque command value for the motor 13. Specifically, the motor torque estimation unit 220 calculates the torque estimate value by estimating the torque using the accelerator opening degree and the actual vehicle speed while the vehicle is traveling.

[0028] The coolant temperature estimation unit 221 estimates (calculates) the temperature of the coolant at the inlet / outlet of each device connected to the thermal circuit 11. Specifically, the coolant temperature estimation unit 221 calculates the estimated temperature of the coolant at the inlet / outlet of each device using the torque estimate of the motor 13 estimated by the motor torque estimation unit 220 and the coolant temperatures detected by the radiator water temperature sensor 22 and the battery water temperature sensor 23.

[0029] In this case, the coolant temperature estimation unit 221 estimates the temperature using a neural network and calculates the estimated temperature. To use the neural network, the coolant temperature estimation unit 221 learns the results of a prior experiment. During the experiment, water temperature sensors are actually installed at the inlets and outlets of each device (motor 13, motor inverter 14, battery 15, radiator 16, DC / DC converter 17, heating-side heat exchanger 18, cooling-side heat exchanger 19, and charger 151) incorporated in the thermal circuit 11, and the coolant temperature at the inlets and outlets of each device is detected. The coolant temperature estimation unit 221 then learns the correspondence between the actual coolant temperature at the inlets and outlets of each device, the rotation speed of the motor 13, the torque estimate, and the coolant temperatures detected by the radiator water temperature sensor 22 and the battery water temperature sensor 23, respectively.

[0030] The current heat dissipation amount calculation unit 222 calculates the amount of heat dissipation for devices connected to the thermal circuit 11 that are dissipating heat, using the coolant temperature and the device temperature. The current heat generation amount calculation unit 226 calculates the amount of heat generated for devices connected to the thermal circuit 11 that are generating heat, using the coolant temperature and the device temperature. Whether a device connected to the thermal circuit 11 is dissipating heat or generating heat is determined based on the difference between the device's inlet and outlet temperatures estimated by the coolant temperature estimation unit 221. Specifically, if the value obtained by subtracting the coolant temperature at the device's inlet from the coolant temperature at the device's outlet is a positive value, the device is determined to be a heat-generating device, and if the value is negative, the device is determined to be a heat-dissipating device. Depending on the running state of the vehicle 10, for example, the motor 13 may be determined to be a heat-generating device, and the radiator 16 or compressor 181 may be determined to be a heat-dissipating device.

[0031] The maximum heat dissipation amount calculation unit 223 calculates the maximum heat dissipation amount obtained when the refrigerant pump 12 and the compressor 181 provided in the air conditioning refrigerant circuit are operated at maximum in the current operating state of the vehicle 10 (vehicle speed, opening / closing of the grill shutter, outside air temperature, etc.). The maximum heat generation amount calculation unit 227 calculates the heat generation amount when the motor 13 operates at maximum torque.

[0032] The heat dissipation capacity margin calculation unit 224 estimates (calculates) a heat dissipation capacity margin, which is the difference between the maximum heat dissipation amount and the current heat dissipation amount, using the calculation results of the current heat dissipation amount calculation unit 222 and the maximum heat dissipation amount calculation unit 223. The heat dissipation capacity margin indicates the margin of heat dissipation capacity of a device determined to be a heat dissipation device.

[0033] The heat generation capacity potential calculation unit 228 estimates (calculates) a heat generation capacity potential, which is the difference between the maximum heat generation amount and the current heat generation amount, using the calculation results of the current heat generation amount calculation unit 226 and the maximum heat generation amount calculation unit 227. The heat generation capacity potential indicates the amount of heat that may be generated in the future from the equipment determined to be a heat-generating equipment. The allowable temperature margin calculation unit 225 calculates an allowable temperature margin from the difference between the estimated (calculated) heat dissipation capacity margin and the heat generation capacity potential. The allowable temperature margin indicates the temperature margin that can be cooled by the refrigerant pump 12.

[0034] The target pump rotation speed calculation unit 229 calculates a target rotation speed of the refrigerant pump 12 based on the allowable temperature margin calculated by the allowable temperature margin calculation unit 225. Specifically, the target pump rotation speed calculation unit 229 references information on the target rotation speed for the allowable temperature margin (target rotation speed information) to obtain a target rotation speed value corresponding to the allowable temperature margin calculated by the allowable temperature margin calculation unit 225. The water pump driver 28 rotates the refrigerant pump 12 at the calculated target rotation speed. As a result, the refrigerant pump 12 is driven at a rotation speed corresponding to the calculated target rotation speed. In other words, the control device 100 controls the rotation speed of the refrigerant pump 12 in accordance with the calculated allowable temperature margin.

[0035] Fig. 3 is a graph showing an example of target rotation speed information. In Fig. 3, the vertical axis represents the target rotation speed [r / min], and the horizontal axis represents the allowable temperature margin [kW]. As shown in Fig. 3, as the allowable temperature margin increases, the target rotation speed decreases linearly. The target rotation speed information is information obtained by various measurements, simulations, etc., and is stored in advance in the non-volatile memory 102.

[0036] The calculation result of target pump rotation speed calculation unit 229 is output to water pump driver 28 via output interface 105 as a target rotation speed signal indicating the rotation speed of refrigerant pump 12. Specifically, as shown in the graph of Fig. 3, the target rotation speed signal is a signal indicating that the rotation speed, i.e., the rotational speed of refrigerant pump 12 should be reduced as the allowable temperature margin increases.

[0037] <Processing of control device 100> The processing executed by the control device 100 will be described below. Fig. 4A is a timing chart showing the relationship between vehicle speed and time, with the vertical axis representing vehicle speed and the horizontal axis representing time. Fig. 4B is a timing chart showing the relationship between outside air temperature and time, with the vertical axis representing outside air temperature and the horizontal axis representing time. Fig. 4C is a timing chart showing the relationship between the coolant temperature at the outlet side of the radiator 16 and time, with the vertical axis representing coolant temperature and the horizontal axis representing time. Fig. 4D is a timing chart showing the relationship between the coolant temperature at the outlet side of the battery 15 and time, with the vertical axis representing coolant temperature and the horizontal axis representing time. Fig. 4E is a timing chart showing the relationship between the open / closed state of the grille shutter and time, with the vertical axis representing a flag indicating the open / closed state and the horizontal axis representing time.

[0038] In the following description, as shown in Figures 4A and 4B, an example is taken in which vehicle 10 is traveling at a speed of 50 km / h on flat ground at an outside temperature of 20°C. At time 60 seconds, vehicle 10 begins accelerating, and the vehicle speed reaches 100 km / h within 20 seconds. Also, as shown in Figure 4D, due to heat generated by battery 15, the coolant temperature at the outlet side of battery 15 is 22°C. Because the coolant temperature at the outlet side of battery 15 is 10°C or higher and the vehicle is in a warmed-up state, the grille shutter is open. That is, as shown in Figure 4E, the flag indicating the open / closed state of the grille shutter is set to 1, indicating that the shutter is open. At this time, the radiator 16 is cooled by the wind flowing in through the open grille shutter, and the coolant temperature at the outlet side of radiator 16 is 20.5°C (see Figure 4C). In the following description, the air conditioning is not in operation, and heat exchange by the heating-side heat exchanger 18 and the cooling-side heat exchanger 19 is not performed.

[0039] Figure 5A shows the relationship between time and the rotation speed of cooling fan 161 provided in radiator 16 detected by fan rotation speed sensor 21 when vehicle 10 is in the above-mentioned driving state. Figure 5B shows the relationship between time and the rotation speed of compressor 181 detected by compressor rotation speed sensor 26 when vehicle 10 is in the above-mentioned driving state. Figure 5C shows the relationship between time and the rotation speed of refrigerant pump 12 detected by water pump rotation speed sensor 27 when vehicle 10 is in the above-mentioned driving state. In Figures 5A, 5B, and 5C, the vertical axis shows rotation speed, and the horizontal axis shows time.

[0040] As described above, since the temperature of the coolant at the outlet side of the radiator 16 is 20.5°C (room temperature) (see FIG. 4C ), the cooling fan 161 provided in the radiator 16 is not rotating, as shown in FIG. 5A . Also, since the air conditioning is not operating as described above, the compressor 181 is not operating, as shown in FIG. 5B . As shown in FIG. 5C , when the vehicle speed is 50 km / h (before time 60 seconds), the rotation speed of the refrigerant pump 12 is 3000 r / min. When the vehicle 10 is traveling at a speed of 50 km / h, the motor torque estimator 220 calculates the torque estimate value as described above.

[0041] 5D shows the relationship between time and the torque estimation value calculated by motor torque estimator 220 when vehicle 10 is in the above-described traveling state. As shown in FIG. 5D, the torque estimation value calculated when the vehicle speed is 50 km / h is 15 Nm.

[0042] The coolant temperature estimation unit 221 uses the torque estimate, the detected coolant temperature (20.5°C) at the outlet side of the radiator 16, and the detected coolant temperature (22°C) at the outlet side of the battery 15 to calculate estimated coolant temperatures at the inlets and outlets of each device connected to the thermal circuit 11. At this time, the coolant temperature estimation unit 221 calculates the estimated coolant temperature at the inlet and outlet of the refrigerant pump 12, the estimated coolant temperature at the inlet and outlet of the cooling-side heat exchanger 19, the estimated coolant temperature at the inlet side of the battery 15, the estimated coolant temperature at the inlet and outlet of the charger 151, the estimated coolant temperature at the inlet and outlet of the DC / DC converter 17 and the estimated temperature of the DC / DC converter 17, the estimated coolant temperature at the inlet and outlet of the motor inverter 14, the estimated temperature of the motor inverter 14, the estimated coolant temperature at the inlet and outlet of the motor 13 and the estimated temperature of the motor 13, the estimated coolant temperature at the inlet and outlet of the heating-side heat exchanger 18, and the estimated temperature at the inlet of the radiator 16.

[0043] When there is a difference between the estimated coolant temperature at the outlet of the radiator 16 and the coolant temperature at the outlet of the radiator 16 detected by the radiator water temperature sensor 22, the coolant temperature estimation unit 221 learns the difference and corrects the estimated temperature. Similarly, when there is a difference between the estimated coolant temperature at the outlet of the battery 15 and the coolant temperature at the outlet of the battery 15 detected by the battery water temperature sensor 23, the coolant temperature estimation unit 221 learns the difference and corrects the estimated temperature.

[0044] Based on the estimated temperature of each device estimated by the cooling water temperature estimation unit 221, devices with a higher cooling water temperature at the outlet than at the inlet are determined to be heat-generating devices, and devices with a lower cooling water temperature at the outlet than at the inlet are determined to be heat-dissipating devices.

[0045] The current heat dissipation amount calculation unit 222 calculates the current heat dissipation amount of the device determined to be a heat dissipation device. Specifically, the current heat dissipation amount calculation unit 222 calculates the current heat dissipation amount by calculating the temperature difference between the inlet temperature and the outlet temperature of the heat dissipation device. Fig. 6A is a timing chart showing the relationship between the calculated current heat dissipation amount and time, with the vertical axis representing the current heat dissipation amount and the horizontal axis representing the time. Fig. 6A shows that the current heat dissipation amount of the heat dissipation device of the vehicle 10 traveling at a speed of 50 km / h is 12 kW.

[0046] The maximum heat dissipation amount calculation unit 223 calculates the maximum heat dissipation amount as the amount of heat that can be dissipated when the rotation speed of the refrigerant pump 12 is increased to the maximum rotation speed from a state in which the vehicle speed is 50 [km / h], and the rotation speed of the compressor 181 is also increased to the maximum rotation speed. Figure 6B is a timing chart showing the relationship between the calculated maximum heat dissipation amount and time, with the vertical axis representing the maximum heat dissipation amount and the horizontal axis representing the time. Figure 6B shows that the maximum heat dissipation amount of the heat dissipation equipment of the vehicle 10 when traveling at a vehicle speed of 50 [km / h] is 35 [kW].

[0047] The heat dissipation capacity margin calculation unit 224 estimates (calculates) the heat dissipation capacity margin of the heat dissipation equipment. As described above, the heat dissipation capacity margin is the difference between the current heat dissipation amount of the heat dissipation equipment calculated by the current heat dissipation amount calculation unit 222 and the maximum heat dissipation amount calculated by the maximum heat dissipation amount calculation unit 223. Figure 6C is a timing chart showing the relationship between the calculated heat dissipation capacity margin and time, with the vertical axis representing the heat dissipation capacity margin and the horizontal axis representing time. Figure 6C shows that the heat dissipation capacity margin of the heat dissipation equipment of the vehicle 10 traveling at a speed of 50 km / h is 23 kW, which is the difference between the current heat dissipation amount (12 kW) and the maximum heat dissipation amount (35 kW) of the heat dissipation equipment.

[0048] The current heat generation amount calculation unit 226 calculates the current heat generation amount of the equipment determined to be a heat-generating equipment. Specifically, the current heat generation amount calculation unit 226 calculates the current heat generation amount by calculating the temperature difference between the inlet temperature and the outlet temperature of the heat-generating equipment. Fig. 7A is a timing chart showing the relationship between the calculated current heat generation amount and time, with the vertical axis representing the current heat generation amount and the horizontal axis representing the time. Fig. 7A shows that the current heat generation amount of the heat-dissipating equipment of the vehicle 10 traveling at a speed of 50 km / h is 12 kW.

[0049] As described above, the maximum heat generation amount calculation unit 227 calculates the heat generation amount when the motor 13 operates at maximum torque. Fig. 7B is a timing chart showing the relationship between the calculated maximum heat generation amount and time, with the vertical axis representing the maximum heat generation amount and the horizontal axis representing the time. Fig. 7B shows that when the torque is increased from 15 [Nm] at the current rotation speed of the motor 13 to the maximum, the maximum heat generation amount of the heat-generating device is 32 [kW]. As shown in Fig. 7B, the maximum heat generation amount remains approximately constant over time.

[0050] The heat generation capacity potential calculation unit 228 estimates (calculates) the heat generation capacity potential of the heat-generating equipment. As described above, the heat generation capacity potential is the difference between the current heat generation amount calculated by the current heat generation amount calculation unit 226 and the maximum heat generation amount calculated by the maximum heat generation amount calculation unit 227. FIG. 7C is a timing chart showing the relationship between the calculated heat generation capacity potential and time, with the vertical axis representing the heat generation capacity potential and the horizontal axis representing the time. FIG. 7C shows that the heat generation capacity potential of the heat-generating equipment of the vehicle 10 traveling at a speed of 50 km / h is 20 kW, which is the difference between the current heat generation amount (12 kW) and the maximum heat generation amount (32 kW) of the heat-generating equipment.

[0051] The allowable temperature margin calculation unit 225 calculates the allowable temperature margin from the difference between the calculated heat dissipation capacity margin and the heat generation capacity potential. Figure 7D is a timing chart showing the relationship between the calculated allowable temperature margin and time, with the vertical axis representing the allowable temperature margin and the horizontal axis representing time. Figure 7D shows that the allowable temperature margin for the vehicle 10 traveling at a speed of 50 km / h is 3 kW, which is the difference between the heat dissipation capacity margin (23 kW) and the heat generation capacity potential (20 kW).

[0052] Let us consider a case where the accelerator pedal is depressed at time 60 seconds while the vehicle 10 is traveling at a speed of 50 km / h, causing acceleration. As shown in Fig. 5D, at time 60 seconds, the torque estimate calculated by the motor torque estimator 220 increases. Because the torque of the motor 13 increases, the current heat generation amount calculated by the current heat generation amount calculator 226 increases (see Fig. 7A). However, as shown in Fig. 7B, because the maximum heat generation amount of the heat-generating device is substantially constant, the heat generation capacity potential calculated by the heat generation capacity potential calculator 228 decreases (see Fig. 7C).

[0053] Furthermore, when the vehicle speed increases due to acceleration, the amount of outside air flowing into the radiator 16 through the grille shutter increases, and the maximum heat dissipation amount calculated by the maximum heat dissipation amount calculation unit 223 also increases (see FIG. 6B). Therefore, the heat dissipation capacity margin calculated by the heat dissipation capacity margin calculation unit 224 as the difference between the current heat dissipation amount and the maximum heat dissipation amount also increases (see FIG. 6C).

[0054] Since the heat dissipation capacity margin increases and the heat generation capacity potential decreases, the allowable temperature margin calculated by the allowable temperature margin calculation unit 225 as the difference between the heat dissipation capacity margin and the heat generation capacity potential increases (see FIG. 7D). When the allowable temperature margin increases, the target pump rotation speed calculation unit 229 decreases the target rotation speed of the refrigerant pump 12 based on the target rotation speed information shown in FIG.

[0055] As a result, the current heat dissipation amount calculated by the current heat dissipation amount calculation unit 222 increases. The increase in the current heat dissipation amount causes the coolant temperature at the outlet of the radiator 16 and the coolant temperature at the outlet of the battery 15 to temporarily increase (see FIGS. 4C and 4D). However, around time 80 [sec] when acceleration ends and motor torque decreases (see FIG. 5D), the coolant temperature at the outlet of the radiator 16 and the coolant temperature at the outlet of the battery 15 decrease again to values ​​approaching the outside air temperature of 20°C (see FIGS. 4C and 4D).

[0056] As a result, when the rotation speed of refrigerant pump 12 is controlled to cool the equipment as vehicle 10 accelerates, the rotation speed of refrigerant pump 12 is prevented from increasing excessively. If the rotation speed of refrigerant pump 12 is too high, the power consumption of refrigerant pump 12 increases, and the amount of heat dissipated by radiator 16 increases, causing the coolant to be excessively cooled. In contrast, in this embodiment, excessive operation of refrigerant pump 12 is prevented, thereby preventing an increase in the power consumption of refrigerant pump 12. As a result, a decrease in the driving range of vehicle 10, which is an electric vehicle, is prevented.

[0057] If the rotation speed of the refrigerant pump 12 is too low, power consumption will decrease, but the amount of heat dissipated from the radiator 16 will decrease, causing the coolant temperature to exceed the desired value, resulting in problems of equipment deterioration, damage, and performance degradation. In contrast, in this embodiment, the rotation speed of the refrigerant pump 12 is reduced based on the allowable temperature margin, preventing the coolant temperature from rising excessively and preventing equipment deterioration, damage, and performance degradation.

[0058] The flow of processing by the control device 100 will be described with reference to Fig. 8. Fig. 8 is a flowchart showing the flow of processing for calculating the rotation speed of the refrigerant pump 12. The processing of the flowchart shown in Fig. 8 is started, for example, when an ignition switch (not shown) of the vehicle 10 is turned on, and is repeatedly executed at a predetermined control period.

[0059] In step S1, the control device 100 detects the coolant temperature based on the signal output from the battery water temperature sensor 23. In step S2, the control device 100 determines whether the detected coolant temperature is 10°C or higher. If the coolant temperature is 10°C or higher, the control device 100 makes a positive determination in step S2, and the process proceeds to step S3. If the coolant temperature is less than 10°C, the control device 100 makes a negative determination in step S2, and the process returns to step S1.

[0060] In step S3, the current heat dissipation amount calculation unit 222 calculates the current heat dissipation amount of the device determined to be a heat dissipation device, and the process proceeds to step S4. As described above, a heat dissipation device is a device for which the coolant temperature on the outlet side is detected to be lower than that on the inlet side based on the estimated temperature estimated by the coolant temperature estimation unit 221.

[0061] In step S4, the current heat generation amount calculation unit 226 calculates the current heat generation amount of the device determined to be a heat generating device, and the process proceeds to step S5. As described above, a heat generating device is a device for which the coolant temperature on the outlet side is detected to be higher than that on the inlet side based on the estimated temperature estimated by the coolant temperature estimation unit 221.

[0062] In step S5, the maximum heat dissipation amount calculation unit 223 calculates the maximum heat dissipation amount when the refrigerant pump 12 and the compressor 181 are operated at maximum, and the process proceeds to step S6. In step S6, the maximum heat generation amount calculation unit 227 calculates the heat generation amount when the motor 13 operates at maximum torque as the maximum heat generation amount, and the process proceeds to step S7.

[0063] In step S7, the heat dissipation capacity margin calculation unit 224 estimates (calculates) the heat dissipation capacity margin using the calculation results obtained in steps S3 and S5, and the process proceeds to step S8. As described above, the heat dissipation capacity margin is the difference between the maximum heat dissipation amount and the current heat dissipation amount.

[0064] In step S8, the heat generation capacity potential calculation unit 228 estimates (calculates) the heat generation capacity potential using the calculation results obtained in step S4 and step S6, and the process proceeds to step S9. As described above, the heat generation capacity potential is the difference between the maximum heat generation amount and the current heat generation amount.

[0065] In step S9, the allowable temperature margin calculation unit 225 calculates the allowable temperature margin from the difference between the heat dissipation capacity margin obtained in step S7 and the heat generation capacity potential obtained in step S8, and the process proceeds to step S10. In step S10, the target pump rotation speed calculation unit 229 calculates the target rotation speed of the refrigerant pump 12 based on the allowable temperature margin obtained in step S9 and the target rotation speed information, and the process proceeds to step S11.

[0066] In step S11, the control device 100 determines whether the refrigerant pump 12 is operating. If the flag indicating that the refrigerant pump 12 is operating is 1, the control device 100 makes a positive determination in step S11, and the process returns to step S1. At this time, the control device 100 outputs a signal to the water pump driver 28 to instruct the refrigerant pump 12 to rotate at the target rotation speed calculated in step S11. If the flag is 0, and the refrigerant pump 12 is not operating, the control device 100 makes a negative determination in step S11, and the process ends.

[0067] According to the above-described first embodiment, the following advantageous effects are achieved.

[0068] (1) The control device 100 is provided with the following functions: a current heat dissipation amount calculation unit 222, a maximum heat dissipation amount calculation unit 223, a heat dissipation capacity margin calculation unit 224, a current heat generation amount calculation unit 226, a maximum heat generation amount calculation unit 227, a heat generation capacity potential calculation unit 228, and an allowable temperature margin calculation unit 225. The current heat dissipation amount calculation unit 222 calculates the current heat dissipation amount of the heat dissipation equipment. The maximum heat dissipation amount calculation unit 223 calculates the maximum heat dissipation amount of the heat dissipation equipment under the current operating conditions. The heat dissipation capacity margin calculation unit 224 calculates a heat dissipation capacity margin based on the difference between the heat dissipation amount and the maximum heat dissipation amount. The current heat generation amount calculation unit 226 calculates the current heat generation amount of the heat-generating equipment. The maximum heat generation amount calculation unit 227 calculates the maximum heat generation amount of the heat-generating equipment. The heat generation capacity potential calculation unit 228 calculates a heat generation capacity potential based on the difference between the heat generation amount and the maximum heat generation amount. The allowable temperature margin calculation unit 225 calculates the allowable temperature margin, which is the difference between the heat dissipation capacity margin and the heat generation capacity potential. The control device 100 controls the rotation speed of the refrigerant pump 12 via the water pump driver 28 in accordance with the calculated allowable temperature margin.

[0069] When the vehicle 10 is not autonomously driven, the vehicle speed constantly changes, and the heat dissipation capacity of the equipment also fluctuates in accordance with the changes in vehicle speed. In conventional vehicles, when accelerating, the heat generated by each equipment increases, and the rotation speed of the refrigerant pump is increased accordingly. At this time, the target temperature for cooling by the refrigerant pump is set to a value that allows a margin relative to the equipment's upper limit temperature in order to protect the equipment. Because this temperature is set to a value with a margin, the refrigerant pump must work to compensate for the margin. In other words, the refrigerant pump is working excessively by the margin. Furthermore, if this margin is too small, the equipment may exceed its upper limit temperature if the vehicle's acceleration time is extended, which could result in equipment deterioration or damage.

[0070] In contrast, in this embodiment, the rotation speed of the refrigerant pump 12 is controlled according to the calculated value of the allowable temperature margin, thereby preventing the refrigerant pump 12 from rotating too fast, which would increase heat radiation from the radiator 16 and cause the coolant to be overcooled. Since the refrigerant pump 12 is prevented from rotating excessively, the power consumption of the refrigerant pump 12 is prevented from increasing excessively, which in turn prevents a reduction in the driving range of the electric vehicle. Furthermore, the rotation speed of the refrigerant pump 12 is prevented from being too slow, which would reduce heat radiation from the radiator 16 and cause the coolant temperature to exceed a desired value. As a result, it is possible to prevent deterioration, damage, and performance degradation of the equipment installed in the vehicle 10.

[0071] (2) The control device 100 reduces the rotation speed of the refrigerant pump 12 in response to an increase in the calculated allowable temperature margin. This prevents the rotation speed of the refrigerant pump 12 from being excessively increased when the refrigerant pump 12 is used to cool equipment. As a result, excessive operation of the refrigerant pump 12 is suppressed, thereby preventing an increase in the power consumption of the refrigerant pump 12. This prevents a decrease in the driving range of the vehicle 10, which is an electric vehicle.

[0072] <Second Embodiment> A vehicle control device according to a second embodiment will be described. Hereinafter, components similar or substantially similar to those in the first embodiment will be assigned the same reference numerals as those in the first embodiment, and differences from the first embodiment will be mainly described. Components that are not specifically described are the same as those in the first embodiment. The second embodiment differs from the first embodiment in that the drive of the radiator cooling fan is also controlled. This will be described in detail below.

[0073] The vehicle control device 1 of the second embodiment has the same configuration as the vehicle control device 1 of the first embodiment shown in Figures 1 and 2. Below, an example will be described in which the control device 100 operates the cooling fan 161 of the radiator 16, which is a heat dissipation device, when the warmed-up vehicle 10 starts climbing a slope after traveling on flat ground. Note that in this embodiment, the air conditioner is not operating, the compressor 181 is not operating, and heat exchange by the cooling-side heat exchanger 19 and the heating-side heat exchanger 18 is not performed.

[0074] FIG. 9A is a timing chart showing the relationship between the slope angle of the vehicle 10 and time, with the vertical axis representing the slope angle and the horizontal axis representing time. FIG. 9B is a timing chart showing the relationship between the altitude of the vehicle 10, which changes as the vehicle 10 climbs a slope, and time, with the vertical axis representing altitude and the horizontal axis representing time. FIG. 9C is a timing chart showing the relationship between vehicle speed and time, with the vertical axis representing vehicle speed and the horizontal axis representing time. FIG. 9D is a timing chart showing the relationship between outside air temperature and time, with the vertical axis representing outside air temperature and the horizontal axis representing time. FIG. 9E is a timing chart showing the relationship between the temperature of the coolant at the outlet side of the radiator 16 and time, with the vertical axis representing the coolant temperature and the horizontal axis representing time. Note that in this embodiment, the relationship between the temperature of the coolant at the outlet side of the battery 15 and time is the same as that shown in FIG. 4D, and it is assumed that the coolant temperature at the outlet side of the battery 15 has risen to 22° C.

[0075] 9A, 9C, and 9D, vehicle 10, after warming up, travels on flat ground for 60 seconds when the outside air temperature is 20°C. Then, vehicle 10 continues to climb a 6-degree gradient (slope) for 40 seconds between 60 and 100 seconds while maintaining a vehicle speed of 50 km / h. After 100 seconds, vehicle 10 travels on a flat road. Also, as shown in FIG. 9B, as vehicle 10 climbs a 6-degree gradient for 40 seconds, the elevation of vehicle 10 changes from 0 m to 58 m.

[0076] Since the vehicle 10 has already warmed up, the coolant temperature is 10°C or higher while traveling on flat ground (see FIG. 9E), and the vehicle 10 is traveling with the grille shutter open. Because the grille shutter is open, the radiator 16 is cooled by the wind from the vehicle. Therefore, during the period from 0 [sec] to 60 [sec] before starting to climb the slope, the coolant temperature at the outlet side of the radiator 16 detected by the radiator water temperature sensor 22 is 20.5°C or lower.

[0077] Fig. 10A is a timing chart showing the relationship between time and the rotation speed of cooling fan 161. Fig. 10B is a timing chart showing the relationship between time and the rotation speed of compressor 181. Fig. 10C is a timing chart showing the relationship between time and the rotation speed of refrigerant pump 12 detected by water pump rotation speed sensor 27 when vehicle 10 is in the above-mentioned running state. In Figs. 10A, 10B, and 10C, the vertical axis shows rotation speed, and the horizontal axis shows time.

[0078] As shown in Fig. 9E, during the period from 0 [sec] to 60 [sec] (i.e., while driving on flat ground), the temperature of the coolant at the outlet side of the radiator 16 is 20.5°C (room temperature), so the cooling fan 161 is not rotating, as shown in Fig. 10A. Also, as mentioned above, the air conditioning is not operating, so the compressor 181 is not operating, as shown in Fig. 10B. As shown in Fig. 10C, when the vehicle speed is 50 [km / h] (before time 60 [sec]), the rotation speed of the refrigerant pump 12 is 3000 [r / min].

[0079] When the vehicle 10 is in the above-described traveling state, the motor torque estimator 220 calculates the torque estimate in the same manner as in the first embodiment. Fig. 10D is a timing chart showing the relationship between the torque estimate and time. When the vehicle 10 is traveling on flat ground at a speed of 50 km / h for a period of 0 to 60 seconds, the calculated torque estimate is 15 Nm, as in the first embodiment.

[0080] As in the first embodiment, the coolant temperature estimation unit 221 calculates an estimated coolant temperature at the inlet / outlet of each device connected to the thermal circuit 11 using the torque estimate, the coolant temperature detected by the radiator coolant temperature sensor 22, and the coolant temperature detected by the battery coolant temperature sensor 23. If there is a difference between the estimated temperature and the coolant temperature detected by the battery coolant temperature sensor 23 or the radiator coolant temperature sensor 22, the coolant temperature estimation unit 221 learns the difference and corrects the estimated temperature, as in the first embodiment.

[0081] The current heat dissipation amount calculation unit 222 calculates the current heat dissipation amount for the devices determined to be heat dissipating devices based on the estimated temperature of each device, in the same manner as in the first embodiment. Fig. 11A is a timing chart showing the relationship between the calculated current heat dissipation amount and time, with the vertical axis representing the current heat dissipation amount and the horizontal axis representing time. As shown in Fig. 11A, the current heat dissipation amount of the heat dissipating devices of the vehicle 10 traveling at a speed of 50 km / h during the period from 0 sec to 60 sec is 12 kW, as in the first embodiment.

[0082] The maximum heat dissipation amount calculation unit 223 calculates the maximum heat dissipation amount in the same manner as in the first embodiment. That is, the maximum heat dissipation amount calculation unit 223 calculates the maximum heat dissipation amount when the rotation speed of the refrigerant pump 12 is increased to the maximum rotation speed from a state in which the outside air temperature is 20°C and the vehicle speed is 50 km / h, thereby increasing the rotation speed of the compressor 181 to the maximum rotation speed. FIG. 11B is a timing chart showing the relationship between the calculated maximum heat dissipation amount and time, with the vertical axis representing the maximum heat dissipation amount and the horizontal axis representing the time. FIG. 11B shows that the maximum heat dissipation amount of the heat dissipation equipment of the vehicle 10 traveling at a vehicle speed of 50 km / h is 35 kW. As shown in FIG. 11B, the maximum heat dissipation amount is constant throughout the entire period.

[0083] The heat dissipation capacity margin calculation unit 224 estimates (calculates) the heat dissipation capacity margin of the heat dissipation equipment in the same manner as in the first embodiment. That is, the heat dissipation capacity margin calculation unit 224 calculates the difference between the current heat dissipation amount of the heat dissipation equipment calculated by the current heat dissipation amount calculation unit 222 and the maximum heat dissipation amount calculated by the maximum heat dissipation amount calculation unit 223. FIG. 11C is a timing chart showing the relationship between the calculated heat dissipation capacity margin and time, with the vertical axis representing the heat dissipation capacity margin and the horizontal axis representing time. FIG. 11C shows that the heat dissipation capacity margin of the heat dissipation equipment of the vehicle 10 traveling at a speed of 50 km / h between 0 sec and 60 sec is 23 kW, which is the difference between the current heat dissipation amount (12 kW) and the maximum heat dissipation amount (35 kW) of the heat dissipation equipment.

[0084] The current heat generation amount calculation unit 226 calculates the current heat generation amount for each device determined to be a heat-generating device based on the estimated temperature of each device in the same manner as in the first embodiment. Fig. 12A is a timing chart showing the relationship between the calculated current heat generation amount and time, with the vertical axis representing the current heat generation amount and the horizontal axis representing the time. Fig. 12A shows that the current heat generation amount of the heat-dissipating device of the vehicle 10 traveling at a speed of 50 km / h between 0 and 60 seconds is 12 kW.

[0085] The maximum heat generation amount calculation unit 227 calculates the heat generation amount when the motor 13 operates at maximum torque, in the same manner as in the first embodiment. Fig. 12B is a timing chart showing the relationship between the calculated maximum heat generation amount and time, with the vertical axis representing the maximum heat generation amount and the horizontal axis representing the time. Fig. 12B shows that when the torque is increased from 15 [Nm] at the current rotation speed of the motor 13 to the maximum, the maximum heat generation amount of the heat-generating device is 32 [kW]. As shown in Fig. 12B, the maximum heat generation amount remains approximately constant over time.

[0086] The heat generation capacity potential calculation unit 228 estimates (calculates) the heat generation capacity potential of the heat-generating equipment in the same manner as in the first embodiment. The heat generation capacity potential is the difference between the current heat generation amount calculated by the current heat generation amount calculation unit 226 and the maximum heat generation amount calculated by the maximum heat generation amount calculation unit 227. FIG. 12C is a timing chart showing the relationship between the calculated heat generation capacity potential and time, with the vertical axis representing the heat generation capacity potential and the horizontal axis representing the time. FIG. 12C shows that the heat generation capacity potential of the heat-generating equipment of the vehicle 10 traveling at a speed of 50 km / h between 0 and 60 seconds is 20 kW, which is the difference between the current heat generation amount (12 kW) and the maximum heat generation amount (32 kW) of the heat-generating equipment.

[0087] The allowable temperature margin calculation unit 225 calculates the allowable temperature margin from the difference between the calculated heat dissipation capacity margin and the heat generation capacity potential, as in the first embodiment. Fig. 12D is a timing chart showing the relationship between the calculated allowable temperature margin and time, with the vertical axis representing the allowable temperature margin and the horizontal axis representing time. Fig. 12D shows that the allowable temperature margin of the vehicle 10 traveling at a speed of 50 km / h between 0 and 60 seconds is 3 kW, which is the difference between the heat dissipation capacity margin (23 kW) and the heat generation capacity potential (20 kW).

[0088] With the accelerator pedal held constant, vehicle 10 starts climbing a slope at 60 seconds. To maintain a constant vehicle speed of 50 km / h, the torque estimate for 40 seconds (60 seconds to 100 seconds) during the climb estimated by motor torque estimator 220 increases to 120 Nm (see FIG. 10D). As a result, as shown in FIG. 12A, the current heat generation amount increases during the period from 60 seconds to 100 seconds. As shown in FIG. 12B, the maximum heat generation amount at maximum torque remains constant, and therefore the heat generation capacity potential decreases as shown in FIG. 12C.

[0089] 9C, the vehicle speed remains constant even when climbing a slope, and therefore, unlike the first embodiment, there is no increase in cooling capacity due to wind from the vehicle as it travels. Therefore, when the torque required for the vehicle speed increases, the control device 100 determines that the vehicle 10 is climbing a slope and drives the cooling fan 161. This allows the radiator 16 to obtain the same cooling capacity as when the vehicle speed increases.

[0090] As shown in FIG. 10A, there is a time lag before the rotation speed of the cooling fan 161, which starts rotating at 60 seconds, reaches the target rotation speed. During the period until the rotation speed of the cooling fan 161 reaches the target rotation speed, the heat dissipation capacity of the radiator 16 is low. Therefore, as shown in FIG. 11A, the current heat dissipation amount increases after 60 seconds. Because the maximum heat dissipation amount is constant as shown in FIG. 11B, the heat dissipation capacity margin, as shown in FIG. 11C, decreases. Due to the decrease in the heat generation capacity potential and the decrease in the heat dissipation capacity margin, the allowable temperature margin decreases as shown in FIG. 12C.

[0091] In this case, it is necessary to increase the rotation speed of the refrigerant pump 12 to improve the cooling capacity. However, as shown in FIG. 10C , when the rotation speed of the cooling fan 161 reaches the target rotation speed around 70 [sec], the maximum heat dissipation amount remains constant (see FIG. 11B ), and the heat dissipation capacity margin shown in FIG. 11C begins to increase. Because the heat generation capacity potential remains reduced, the increase in the heat dissipation capacity margin around 70 [sec] causes the allowable temperature margin to begin to increase as shown in FIG. 12D . That is, as the cooling fan 161 reaches the target rotation speed, the cooling capacity of the radiator 16 improves and the allowable temperature margin increases. As shown in FIG. 3 , as the allowable temperature margin increases, the rotation speed of the refrigerant pump 12 decreases. Therefore, as shown in FIG. 10C , it becomes possible to reduce the rotation speed of the refrigerant pump 12 around 70 [sec]. That is, the control device 100 controls the rotation speed of the refrigerant pump 12 in accordance with the allowable temperature margin, which changes as the cooling fan 161 is driven. As a result, the power consumed by the refrigerant pump 12 can be reduced.

[0092] According to the second embodiment described above, in addition to the effects (1) and (2) obtained in the first embodiment, the following effects are obtained.

[0093] (3) The control device 100 controls the rotation speed of the refrigerant pump 12 in accordance with the allowable temperature margin that changes as the cooling fan 161 is driven. This prevents excessive cooling by the refrigerant pump 12 when the driving condition of the vehicle 10 changes from flat ground to uphill and the cooling capacity is improved by rotating the cooling fan 161 of the radiator 16. As a result, an increase in power consumption by the refrigerant pump 12 is prevented, and a decrease in the driving distance of the vehicle 10, which is an electric vehicle, is prevented.

[0094] In the second embodiment described above, the vehicle 10 is traveling uphill. However, the vehicle 10 may transition from traveling on flat ground with the motor 13 driven at a constant torque and the refrigerant pump 12 operating at a constant rotational speed to traveling downhill and increasing its vehicle speed. In this case, the amount of heat generated by the motor 13 remains constant, but the vehicle speed increases, increasing the amount of outside air (driving wind) flowing in through the grille shutter and increasing the heat dissipation capacity of the radiator 16. Even in this case, the rotational speed of the refrigerant pump 12 is controlled in accordance with the calculated allowable temperature margin. As a result, excessive cooling of the coolant is prevented, which reduces the increase in power consumption due to excessive operation of the refrigerant pump 12 and reduces the reduction in the driving range of the electric vehicle 10.

[0095] <Third Embodiment> A vehicle control device according to a third embodiment will be described. Hereinafter, components similar or substantially similar to those in the first or second embodiment will be assigned the same reference numerals as those in the first or second embodiment, and differences from the first or second embodiment will be mainly described. Components not specifically described are similar to those in the first or second embodiment. The third embodiment differs from the first and second embodiments in that it controls the drive of the compressor in addition to the radiator cooling fan. This will be described in detail below.

[0096] The vehicle control device 1 of the third embodiment has the same configuration as the vehicle control device 1 of the first embodiment shown in Figures 1 and 2. Hereinafter, an example will be described in which the vehicle 10, after warming up, travels on flat ground and then climbs a slope in an environment where the outside air temperature is 40°C. Since the outside air temperature is 40°C, the temperature of the vehicle 10 is set to 24°C by the air conditioner. However, the air conditioner only cools the passenger compartment (cabin) when the vehicle 10 is traveling on flat ground. Therefore, heat exchange by the cooling-side heat exchanger 19 and the heating-side heat exchanger 18 is not performed when the vehicle 10 is traveling on flat ground.

[0097] FIG. 13A is a timing chart showing the relationship between the slope angle of the vehicle 10 and time, with the vertical axis representing the slope angle and the horizontal axis representing time. FIG. 13B is a timing chart showing the relationship between the altitude of the vehicle 10, which changes as the vehicle 10 climbs a slope, and time, with the vertical axis representing altitude and the horizontal axis representing time. FIG. 13C is a timing chart showing the relationship between the vehicle speed and time, with the vertical axis representing vehicle speed and the horizontal axis representing time. FIG. 13D is a timing chart showing the relationship between the outside air temperature and time, with the vertical axis representing outside air temperature and the horizontal axis representing time. FIG. 13E is a timing chart showing the relationship between the coolant temperature at the outlet side of the radiator 16 and time, with the vertical axis representing the coolant temperature and the horizontal axis representing time. Note that in this embodiment, the relationship between the coolant temperature at the outlet side of the battery 15 and time is the same as that shown in FIG. 4D, and it is assumed that the coolant temperature at the outlet side of the battery 15 has risen to 22°C.

[0098] 13A, 13C, and 13D, vehicle 10, after warming up, travels on flat ground for 60 seconds when the outside air temperature is 40° C. Then, vehicle 10 continues to climb a 4-degree gradient (slope) for 40 seconds between 60 and 100 seconds while maintaining a vehicle speed of 50 km / h. After 100 seconds, vehicle 10 travels on a flat road. Also, as shown in FIG. 13B, as vehicle 10 climbs a 4-degree gradient for 40 seconds, the elevation of vehicle 10 changes from 0 m to 39 m.

[0099] Fig. 14A is a timing chart showing the relationship between time and the rotation speed of cooling fan 161 detected by fan rotation speed sensor 21. Fig. 14B is a timing chart showing the relationship between time and the rotation speed of compressor 181 detected by compressor rotation speed sensor 26. Fig. 14C is a timing chart showing the relationship between time and the rotation speed of refrigerant pump 12 detected by water pump rotation speed sensor 27 when vehicle 10 is in the above-mentioned running state. In Figs. 14A, 14B, and 14C, the vertical axis shows rotation speed, and the horizontal axis shows time.

[0100] As shown in Fig. 13D, since the outside air temperature is 40°C, the control device 100 drives the cooling fan 161 of the radiator 16 for the entire period from [sec] seconds onwards while the vehicle 10 is traveling on flat ground. As shown in Fig. 14A, the rotation speed of the cooling fan 161 is set to 3500 [r / min] for the entire period. As a result, as shown in Fig. 13E, the temperature of the coolant at the outlet side of the radiator 16 when the vehicle is traveling on flat ground is 38°C.

[0101] Furthermore, the temperature inside the vehicle 10 is set to 24° C., and therefore the compressor 181 is operating. As shown in Fig. 14B, when the vehicle 10 is traveling on flat ground, the rotation speed of the compressor 181 is set to 2000 r / min. As shown in Fig. 14C, when the vehicle speed is 50 km / h (before time 60 seconds), the rotation speed of the refrigerant pump 12 is 3300 r / min.

[0102] When the vehicle 10 is in the above-described traveling state, the motor torque estimator 220 calculates a torque estimate in the same manner as in the first and second embodiments. Fig. 14D is a timing chart showing the relationship between the torque estimate and time. When the vehicle 10 is traveling on flat ground at a vehicle speed of 50 km / h for a period of 0 to 60 seconds, the calculated torque estimate is 15 Nm, as in the first and second embodiments.

[0103] The coolant temperature estimation unit 221, the current heat dissipation amount calculation unit 222, the maximum heat dissipation amount calculation unit 223, and the heat dissipation capacity margin calculation unit 224 perform the same processing as in the first and second embodiments, thereby calculating the current heat dissipation amount, the maximum heat dissipation amount, and the heat dissipation capacity margin.

[0104] 15A is a timing chart showing the relationship between the calculated current heat dissipation amount and time, where the vertical axis represents the current heat dissipation amount and the horizontal axis represents time. As shown in FIG. 15A, the current heat dissipation amount of the heat dissipation equipment of the vehicle 10 traveling at a speed of 50 km / h during the period from 0 sec to 60 sec is 12 kW, as in the first and second embodiments.

[0105] 15B is a timing chart showing the relationship between the calculated maximum heat dissipation amount and time, with the vertical axis representing the maximum heat dissipation amount and the horizontal axis representing the time. In FIG. 15B, the maximum heat dissipation amount of the heat dissipation equipment of the vehicle 10 traveling at a speed of 50 km / h is shown to be 33 kW. The reason why the maximum heat dissipation amount in the third embodiment is lower than that in the second embodiment is that in the third embodiment, part of the work of the compressor 181 is allocated to the use of the air conditioner.

[0106] 15C is a timing chart showing the relationship between the calculated heat dissipation capacity margin and time, with the vertical axis representing the heat dissipation capacity margin and the horizontal axis representing time. In FIG. 15C, the heat dissipation capacity margin of the heat dissipation equipment of vehicle 10 traveling at a speed of 50 km / h between 0 and 60 seconds is shown to be 21 kW, which is the difference between the current heat dissipation amount (12 kW) and the maximum heat dissipation amount (33 kW) of the heat dissipation equipment.

[0107] The current heat generation amount calculation unit 226, the maximum heat generation amount calculation unit 227, and the heat generation capacity potential calculation unit 228 perform the same processing as in the first and second embodiments. As a result, the current heat generation amount, the maximum heat generation amount, and the heat generation capacity margin are calculated. However, the maximum heat generation amount calculation unit 227 calculates the maximum heat generation amount when the rotation speeds of the refrigerant pump 12 and the compressor 181 are increased to their maximum rotation speeds, based on information related to the outside air temperature, the vehicle speed, and the grille shutter.

[0108] 16A is a timing chart showing the relationship between the calculated current heat generation amount and time, with the vertical axis representing the current heat generation amount and the horizontal axis representing time. In FIG. 16A, the current heat generation amount of the heat dissipation equipment of the vehicle 10 traveling at a speed of 50 km / h is shown to be 12 kW between 0 and 60 seconds.

[0109] 16B is a timing chart showing the relationship between the calculated maximum heat generation amount and time, with the vertical axis representing the maximum heat generation amount and the horizontal axis representing the time. Fig. 16B shows that when the torque is increased from 15 [Nm] at the current rotation speed of motor 13 to the maximum, the maximum heat generation amount of the heat-generating device is 32 [kW]. As shown in Fig. 16B, the maximum heat generation amount remains approximately constant over time.

[0110] 16C is a timing chart showing the relationship between the calculated heat generation capacity potential and time, with the vertical axis representing the heat generation capacity potential and the horizontal axis representing the time. In FIG. 16C, the heat generation capacity potential of the heat-generating devices of the vehicle 10 traveling at a speed of 50 km / h between 0 and 60 seconds is shown to be 20 kW, which is the difference between the current heat generation amount (12 kW) and the maximum heat generation amount (32 kW) of the heat-generating devices.

[0111] The allowable temperature margin calculation unit 225 calculates the allowable temperature margin from the difference between the calculated heat dissipation capacity margin and the heat generation capacity potential, as in the first and second embodiments. Fig. 16D is a timing chart showing the relationship between the calculated allowable temperature margin and time, with the vertical axis representing the allowable temperature margin and the horizontal axis representing time. Fig. 16D shows that the allowable temperature margin for the vehicle 10 traveling at a speed of 50 km / h between 0 and 60 seconds is 1 kW, which is the difference between the heat dissipation capacity margin (21 kW) and the heat generation capacity potential (20 kW).

[0112] With the accelerator pedal held constant, vehicle 10 starts climbing a slope at 60 seconds. To maintain a constant vehicle speed of 50 km / h, the torque estimate for 40 seconds (60 seconds to 10 seconds) during the climb estimated by motor torque estimator 220 increases to 100 Nm (see FIG. 14D). As a result, as shown in FIG. 16A, the current heat generation amount increases to 26 kW during the period from 60 seconds to 100 seconds. As shown in FIG. 16B, the maximum heat generation amount at maximum torque remains constant, and therefore the heat generation capacity potential decreases to 6 kW as shown in FIG. 16C.

[0113] In the third embodiment, unlike the second embodiment, the cooling fan 161 is operating when the vehicle 10 is traveling on flat ground. Therefore, the radiation capacity margin is lower than in the second embodiment shown in Fig. 11C (see Fig. 15C). When the vehicle 10 starts climbing at 60 [sec], the heat generation capacity potential decreases as described above, and accordingly, the allowable temperature margin temporarily decreases as shown in Fig. 16D.

[0114] The control device 100 increases the rotation speed of the refrigerant pump 12 in response to a decrease in the allowable temperature margin (see FIG. 14C). The control device 100 determines that the vehicle 10 is climbing a slope because the torque estimate value increases relative to the vehicle speed (see FIGS. 13C and 14D). In this case, the control device 100 increases the rotation speed of the compressor 181 from 2000 r / min to 5000 r / min (see FIG. 14B) to increase the heat dissipation capacity in response to the increase in heat generation. At this time, the work of the compressor 181 generated by the increased rotation speed is used to cool the coolant by the cooling-side heat exchanger 19 and the heating-side heat exchanger 18.

[0115] As the rotation speed of the compressor 181 increases, the current heat radiation amount decreases at time t [sec] (see FIG. 15A), thereby increasing the heat radiation capacity margin (see FIG. 15C). As the radiation capacity margin increases, the allowable temperature margin increases at time t [sec], as shown in FIG. 16D. Because the allowable temperature margin increases, the control device 100 reduces the rotation speed of the refrigerant pump 12 at time t [sec] (see FIG. 14C). As a result, when the rotation speed of the compressor 181 is increased to cool the coolant in response to an increase in the amount of heat generated, the rotation speed of the refrigerant pump 12 can be controlled in accordance with the allowable temperature margin. Therefore, excessive power consumption by the refrigerant pump 12 is suppressed.

[0116] According to the third embodiment described above, in addition to the effects (1) to (3) obtained by the first and second embodiments described above, the following effects can be obtained.

[0117] (4) The control device 100 controls the rotation speed of the refrigerant pump 12 in accordance with the allowable temperature margin that changes as the compressor 181 is driven. This prevents excessive cooling by the refrigerant pump 12 when the outside air temperature of the vehicle 10 is high and the driving state changes from flat ground to uphill, causing the compressor 181 to drive. As a result, an increase in power consumption by the refrigerant pump 12 is suppressed, and a decrease in the driving range of the vehicle 10, which is an electric vehicle, is suppressed.

[0118] <Fourth embodiment> A vehicle control device according to the fourth embodiment will be described. Hereinafter, components similar or substantially similar to those in the first to third embodiments will be assigned the same reference numerals as those in the first to third embodiments, and differences from the first to third embodiments will be mainly described. Components that are not specifically described are similar to the first to third embodiments. The fourth embodiment differs from the first to third embodiments in that the vehicle is capable of autonomous driving based on information input from a navigation device.

[0119] 17 is a block diagram showing the configuration of a control system of a vehicle control device 1 provided in a vehicle 10 of the fourth embodiment. As shown in FIG.

[0120] The navigation device 30 is a device that performs road condition and route search, and outputs information about the destination set by the user through a setting operation and information about the road conditions to the control device 100. The control device 100 searches for a route to the destination based on the information output from the navigation device 30. Furthermore, based on the information output from the navigation device 30, the control device 100 detects road conditions such as the gradient and curvature of the route to the destination, whether it is an urban area with many traffic lights or a suburban area with few traffic lights, and whether there is congestion. Then, the control device 100 determines a route to the destination from the searched routes based on the detected road conditions.

[0121] The following describes the processing performed by the control device 100. In the following description, it is assumed that the distance from the current location to the destination is 18 km based on the guidance information output from the navigation device 30. Furthermore, the air conditioner is not running, and therefore the compressor 181 is not operating.

[0122] The control device 100 determines the target speed for the route to the destination, taking into consideration the speed limit, the presence or absence of traffic congestion, etc. Fig. 18A is a diagram showing the relationship between the target speed and the distance from the current position, with the vertical axis representing the target speed and the horizontal axis representing the distance. Fig. 18B is a diagram showing the relationship between the altitude and the distance from the current position, based on information output by the navigation device 30, with the vertical axis representing the altitude and the horizontal axis representing the distance.

[0123] In order to realize the determined target speed, the control device 100 determines the target torque of the motor 13 while also taking into consideration information about the altitude. Fig. 18C is a diagram showing the relationship between the target torque and the distance from the current position, with the vertical axis representing the target torque and the horizontal axis representing the distance.

[0124] FIG. 19A is a diagram showing the relationship between outside air temperature and distance from the current location, with the vertical axis representing outside air temperature and the horizontal axis representing distance. FIG. 19B is a diagram showing the relationship between coolant temperature and distance from the current location, with the vertical axis representing coolant temperature and the horizontal axis representing distance. The control device 100 determines whether warm-up is necessary based on the outside air temperature and the coolant temperature. As shown in FIGS. 19A and 19B, the outside air temperature and the coolant temperature at the current location are both 22°C. Therefore, the control device 100 determines that the vehicle 10 has been warmed up.

[0125] Since the vehicle 10 has warmed up, the control device 100 opens the grill shutter to allow air to flow into the engine compartment. Figure 19C is a diagram showing the relationship between the open / closed status of the grill shutter and the distance from the current position, with the vertical axis representing the value of the grill shutter open / close flag and the horizontal axis representing the distance. Since the grill shutter is open, the value of the grill shutter open flag is set to 1, indicating that the grill shutter is in the open state.

[0126] 19D is a diagram showing the relationship between the actual vehicle speed of the vehicle 10 and the distance from the current position, where the vertical axis represents the actual vehicle speed and the horizontal axis represents the distance. The actual vehicle speed is detected by a vehicle speed sensor (not shown).

[0127] The motor torque estimator 220, the coolant temperature estimator 221, the current heat dissipation amount calculator 222, the maximum heat dissipation amount calculator 223, the heat dissipation capacity margin calculator 224, the allowable temperature margin calculator 225, the current heat generation amount calculator 226, the maximum heat generation amount calculator 227, and the heat generation capacity potential calculator 228 perform the same processing as in the first to third embodiments. As a result, the current heat generation amount, the maximum heat generation amount, the heat dissipation capacity margin, the current heat generation amount, the maximum heat generation amount, the heat generation capacity potential, and the allowable temperature margin are calculated at the start of running and during running. Then, the target pump rotation speed calculator 229 determines the rotation speed of the refrigerant pump 12, similarly to the first to third embodiments.

[0128] FIG. 20A shows the relationship between the rotation speed of the cooling fan 161 and the distance from the current position. FIG. 20B shows the relationship between the rotation speed of the compressor 181 and the distance from the current position. FIG. 20C shows the relationship between the rotation speed of the refrigerant pump 12 and the distance from the current position. In FIGS. 20A, 20B, and 20C, the vertical axis shows the rotation speed, and the horizontal axis shows the distance. FIG. 20D shows the relationship between the torque estimation value calculated by the motor torque estimator 220 and the distance from the current position. When the load on the motor 13 is low, i.e., when the torque estimation value is low, the control device 100 determines that the heat dissipation capacity of the cooling fan 161 is sufficient, and sets the target rotation speed of the cooling fan 161 to 0 [r / min] (see FIG. 20A).

[0129] Fig. 21A is a diagram showing the relationship between the calculated current heat dissipation amount and the distance from the current location, with the vertical axis representing the current heat dissipation amount and the horizontal axis representing the distance. Fig. 21B is a diagram showing the relationship between the calculated maximum heat dissipation amount and the distance from the current location, with the vertical axis representing the maximum heat dissipation amount and the horizontal axis representing the distance. Fig. 21C is a diagram showing the relationship between the calculated heat dissipation capacity margin and the distance from the current location, with the vertical axis representing the heat dissipation capacity margin and the horizontal axis representing the distance.

[0130] Fig. 22A is a diagram showing the relationship between the calculated current heat generation amount and the distance from the current location, with the vertical axis representing the current heat generation amount and the horizontal axis representing the distance. Fig. 22B is a diagram showing the relationship between the calculated maximum heat generation amount and the distance from the current location, with the vertical axis representing the maximum heat generation amount and the horizontal axis representing the distance. Fig. 22C is a diagram showing the relationship between the calculated heat generation capacity potential and the distance from the current location, with the vertical axis representing the heat generation capacity potential and the horizontal axis representing the distance. Fig. 22D is a diagram showing the relationship between the calculated allowable temperature margin and the distance from the current location, with the vertical axis representing the allowable temperature margin and the horizontal axis representing the distance.

[0131] As shown in FIG. 18B, at point D (hereafter referred to as point D), the altitude increases and vehicle 10 begins climbing. If the torque estimate is higher than the target torque at point D (see FIGS. 18C and 20D), control device 100 sets the rotation speed of cooling fan 161 to the target rotation speed corresponding to the torque estimate. That is, at point D, as shown in FIG. 20A, the rotation speed of cooling fan 161 increases. This increases the airflow to radiator 16, and therefore the current heat dissipation amount and maximum heat dissipation amount increase at point D (see FIGS. 21A and 21B). As a result, the heat dissipation capacity margin also increases, as shown in FIG. 21C.

[0132] While the vehicle 10 is climbing a slope, the torque of the motor 13 increases, and therefore the current heat generation amount increases at point D (see FIG. 22A). Since the maximum heat generation amount remains constant throughout the entire traveling period of the vehicle 10 (see FIG. 22B), the heat generation capacity potential decreases at point D (see FIG. 22C).

[0133] As described above, the cooling fan 161 operates while traveling uphill, increasing the maximum heat dissipation amount and the heat dissipation capacity margin. Therefore, even if the current heat generation amount increases as the torque of the motor 13 increases, the allowable temperature margin increases at point D (see FIG. 22D). Because the allowable temperature margin has increased, the control device 100 reduces the rotation speed of the refrigerant pump 12 at point D (see FIG. 20C). This controls the rotation speed of the refrigerant pump 12 according to the allowable temperature margin, thereby preventing excessive power consumption by the refrigerant pump 12. As a result, the same effects as those obtained by the second embodiment can be achieved.

[0134] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and the technical scope of the present invention is not intended to be limited to the specific configurations of the above embodiments. Note that the control lines and information lines shown in the figures are those considered necessary for explanation, and do not necessarily represent all control lines and information lines necessary for the product. In reality, it can be assumed that almost all components are interconnected.

[0135] REFERENCE SIGNS LIST 1 Vehicle control device, 10 Vehicle, 11 Thermal circuit, 12 Refrigerant pump, 13 Motor, 14 Motor inverter, 15 Battery, 16 Radiator, 17 DC / DC converter, 18 Heating side heat exchanger, 19 Cooling side heat exchanger, 20 Grille shutter opening / closing sensor, 21 Fan rotation speed sensor, 22 Radiator water temperature sensor, 23 Battery water temperature sensor, 24 Motor rotation speed sensor, 25 Outside air temperature sensor, 26 Compressor rotation speed sensor, 27 Water pump rotation speed sensor, 28 Water pump driver 28, 100 Control device, 101 Calculation device, 161 Cooling fan, 181 Compressor, 220 Motor torque estimation unit, 221 Cooling water temperature estimation unit, 222 Current heat dissipation amount calculation unit, 223 Maximum heat dissipation amount calculation unit, 224 Heat dissipation capacity margin calculation unit, 225 Allowable temperature margin calculation unit, 226 Current heat generation amount calculation unit, 227 Maximum heat generation amount calculation unit, 228 Heat generation capacity potential calculation unit, 229 Target pump rotation speed calculation unit 229

Claims

1. A vehicle control device having a control device that controls a refrigerant pump mounted on a vehicle, the vehicle having a heat-generating device that generates heat while driving, a heat-dissipating device that dissipates heat generated by the heat-generating device, and the refrigerant pump that sends refrigerant that has absorbed the heat generated by the heat-generating device to the heat-dissipating device, the vehicle control device: calculates a current heat dissipation amount of the heat-dissipating device, calculates a maximum heat dissipation amount of the heat-dissipating device under current driving conditions, calculates a heat dissipation capacity margin based on the difference between the heat dissipation amount and the maximum heat dissipation amount, calculates a current heat generation amount of the heat-generating device, calculates a maximum heat generation amount of the heat-generating device, calculates a heat generation capacity potential based on the difference between the heat generation amount and the maximum heat generation amount, and controls the rotation speed of the refrigerant pump in accordance with an allowable temperature margin that is the difference between the heat dissipation capacity margin and the heat generation capacity potential.

2. A vehicle control device according to claim 1, wherein the control device reduces the rotation speed of the refrigerant pump in response to an increase in the allowable temperature margin.

3. A vehicle control device according to claim 1, wherein the heat dissipation device is a cooling fan of a radiator, and the control device controls the rotation speed of the refrigerant pump in accordance with the allowable temperature margin that changes as the cooling fan is driven.

4. A vehicle control device according to claim 1, wherein the heat dissipation device is a compressor, and the control device controls the rotation speed of the refrigerant pump in accordance with the allowable temperature margin that changes as the compressor is driven.

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