Vehicle control device

Abstract

To provide a vehicular control device capable of avoiding restriction of output of a motor due to protection of the motor.SOLUTION: In a hybrid vehicle, an oil cooling type for cooling a power generation motor and a drive motor by using oil is adopted. In an oil cooler, oil is cooled by exchanging heat with cooling water flowing in a cooling water circulation passage. In normal control (S2), a flow rate of the cooling water is controlled to a flow rate corresponding to a cooling water temperature. While the normal control is being performed, when at least one of a temperature of the power generation motor (MG1 temperature) and a temperature of the drive motor (MG2 temperature) reaches a control start threshold value or larger (YES in S1), driving of an electric water pump is controlled so that a flow rate of the cooling water flowing in the cooling water circulation passage increases to a maximum discharge flow rate of the electric water pump (S2).SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a control device for use in a vehicle equipped with a motor. [Background technology]

[0002] For example, a series-type hybrid vehicle is equipped with a generator motor that generates electricity using engine power and a drive motor that generates power for driving. The generator motor and drive motor are housed in a unit case together with a differential gear and are unitized as a transaxle.

[0003] Hybrid vehicles are equipped with a PCU (Power Control Unit) that incorporates an inverter and a microcontroller to drive the motor (power generation motor and drive motor). When the motor is operating, heat is generated due to copper loss and iron loss, so the motor needs to be cooled to operate continuously. In addition, the PCU needs to be cooled to prevent thermal damage to the electronic components inside the PCU. For this reason, hybrid vehicles are equipped with an HV cooling system that cools the motor and PCU.

[0004] The HV cooling system uses an oil cooling method to cool the motor with oil. An oil pump is installed inside the transaxle unit case, and when the oil pump is driven, the oil that has accumulated at the bottom of the unit case is sucked up by the oil pump, and the oil discharged from the oil pump is supplied to the motor.

[0005] On the other hand, the HV cooling system employs a water-cooling method for the PCU, which uses coolant to cool the PCU. The HV cooling system is provided with a coolant circuit through which coolant circulates by the operation of an electric water pump. The coolant circuit passes through the PCU, and heat is exchanged between the PCU and the coolant as the coolant circulates through the circuit. The coolant circuit also passes through an oil cooler provided in the transaxle, and in the oil cooler, heat is exchanged between the coolant and the oil used to cool the motor in the transaxle. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2013-56615 A [Patent Document 2] JP 2014-3752 A Summary of the Invention [Problem to be solved by the invention]

[0007] In order to control the operation of the electric water pump, a relationship between the temperature of the coolant circulating through the coolant circuit (coolant temperature) and the coolant discharge flow rate (W / P required flow rate) required by the electric water pump is set, as shown in FIG. 5. In controlling the operation of the electric water pump, the coolant temperature is detected, and the W / P required flow rate corresponding to the detected coolant temperature is set based on the relationship between the coolant temperature and the W / P required flow rate. That is, when the coolant temperature is below a certain lower limit temperature, the W / P required flow rate is set to the minimum discharge flow rate of the electric water pump, when the coolant temperature is above a certain upper limit temperature, the W / P required flow rate is set to the maximum discharge flow rate of the electric water pump, and when the coolant temperature is between the lower limit temperature and the upper limit temperature, the W / P required flow rate is set to a value that increases with the increase in the coolant temperature. Then, the operation of the electric water pump is controlled so that the discharge flow rate of the electric water pump coincides with the W / P required flow rate.

[0008] Therefore, when the coolant temperature is low, such as when driving at high speeds or when the outside air temperature is low, the W / P required flow rate is set to a small value and the flow rate of the coolant circulating through the coolant circuit is limited to a low flow rate.If the flow rate of the coolant is limited to a low flow rate during high output when the motor generates a lot of heat, the amount of heat exchange in the oil cooler decreases, resulting in insufficient cooling of the oil, and the temperature of the oil and motor rise, which may cause the output of the motor to be limited to protect the motor.

[0009] An object of the present invention is to provide a vehicle control device that can avoid limiting the output of a motor in order to protect the motor. [Means for solving the problem]

[0010] In order to achieve the above-mentioned object, the vehicle control device of the present invention is a control device used in a vehicle equipped with a motor and a cooling system that cools oil by heat exchange with cooling water flowing through a cooling water passage and cools the motor with the oil, and includes a flow control means for controlling the flow rate of the cooling water to a flow rate according to the temperature of the cooling water, and a heat exchange amount increasing means for increasing the amount of heat exchange between the oil and the cooling water when a variable correlated with the motor temperature becomes equal to or exceeds a predetermined value while control is being performed by the flow control means.

[0011] According to this configuration, a vehicle equipped with a motor employs an oil-cooling system in which the motor is cooled by oil, and the oil is cooled by heat exchange with coolant flowing through a cooling water passage. Normally, the flow rate of the coolant is controlled to a flow rate according to the temperature of the coolant. When a variable correlated with the motor temperature reaches or exceeds a predetermined value while this control is being performed, the amount of heat exchanged between the oil and the coolant is increased. The increase in the amount of heat exchanged between the oil and the coolant reduces the oil temperature, thereby preventing the motor from becoming too hot and avoiding the output of the motor being limited to protect the motor.

[0012] The variable correlated with the motor temperature may be, for example, the temperature of the stator core of the motor detected by a thermistor, or the temperature of the oil supplied to the motor. When the temperature of the stator core of the motor increases, the temperature of the oil increases accordingly, so that the temperature of the oil has a positive correlation with the temperature of the stator core.

[0013] The heat exchange amount increasing means may include a flow rate increasing means for increasing the flow rate of the cooling water to a value higher than the flow rate controlled by the flow rate control means. By increasing the flow rate of the cooling water, the amount of heat exchanged between the oil and the cooling water can be increased.

[0014] In addition, in a configuration in which the cooling system includes a cooling device that cools the coolant, the heat exchange amount increasing means may include a cooling capacity increasing means that increases the cooling capacity of the cooling device. By increasing the cooling capacity of the cooling device, the temperature of the coolant can be lowered, and therefore the amount of heat exchange between the oil and the coolant can be increased.

[0015] The cooling system may include an electric water pump that discharges coolant into a cooling water passage, and the control device may further include a memory means for storing the relationship between the temperature and flow rate of the coolant, and the flow rate control means may be configured to set a flow rate according to the temperature of the coolant from the relationship stored in the memory means, and to control the electric water pump so that the flow rate of the coolant becomes the set flow rate. Effect of the Invention

[0016] According to the present invention, it is possible to prevent the motor from becoming too hot, and to avoid limiting the output of the motor in order to protect the motor. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a skeleton diagram showing a configuration of a power transmission system of a hybrid vehicle. [Diagram 2] FIG. 1 is a diagram illustrating a configuration of a cooling system of a hybrid vehicle. [Diagram 3]1 is a block diagram showing a configuration of a control system for a hybrid vehicle (a configuration including a control device according to an embodiment of the present invention). [Figure 4] 13 is a flowchart showing the flow of a flow rate control process. [Diagram 5] 4 is a graph showing the relationship between the cooling water temperature and the W / P required flow rate (cooling water flow rate). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0019] <Hybrid vehicle power transmission system> FIG. 1 is a skeleton diagram showing the configuration of a power transmission system of a hybrid vehicle 1. As shown in FIG.

[0020] The hybrid vehicle 1 is a vehicle equipped with a series hybrid system. The hybrid vehicle 1 is equipped with an engine 2, a generator motor (MG1) 3, and a drive motor (MG2) 4.

[0021] The engine 2 is, for example, a gasoline engine, and is equipped with an electronic throttle valve for adjusting the amount of intake air into the combustion chamber, an injector (fuel injection device) for injecting fuel into the intake air, and a spark plug for generating an electric discharge in the combustion chamber, etc. An engine gear 12 is provided on a crankshaft 11, which is the output shaft of the engine 2, so as to rotate integrally with the crankshaft 11.

[0022] The generator motor 3 and the drive motor 4 are, for example, permanent magnet synchronous motors (PMSMs). The permanent magnet synchronous motor includes a stator and a rotor. The stator includes a stator core and a coil. The stator core includes an annular (cylindrical) stator yoke and a plurality of teeth extending radially inward from the stator yoke, and the coils are wound around each tooth in a concentrated manner. The rotor is disposed inside the stator and includes an annular rotor yoke concentric with the stator yoke and a plurality of permanent magnets embedded in the rotor yoke in a line in the circumferential direction. When a current flows through the coil of the stator, a magnetic flux is generated that extends in the rotational radial direction along the teeth, and this magnetic flux acts on the permanent magnet of the rotor, generating a rotational force in the rotor. Therefore, by controlling the current flowing through the coil according to the rotational position of the rotor, a rotational force is continuously generated in the rotor, causing the rotor to rotate.

[0023] A rotating shaft 13 is inserted through the center of the rotor of the generator motor 3 so as to be unable to rotate relative to the engine (so as to rotate together). A generator motor gear 14 is provided on the rotating shaft 13 so as to rotate together with the engine gear 12. The generator motor gear 14 is engaged with the engine gear 12.

[0024] A rotating shaft 15 is inserted through the center of the rotor of the drive motor 4 so as to be non-rotatable relative to the hybrid vehicle 1. A drive motor gear 16 is provided on the rotating shaft 15 so as to rotate integrally therewith, and the rotating shaft 15 is connected to a drive system of the hybrid vehicle 1 via the drive motor gear 16. The drive system includes a counter shaft 21, a counter gear 22, and a differential gear 23. The counter shaft 21 extends parallel to the rotating shaft 15. The counter gear 22 is supported on the counter shaft 21 so as not to be rotatable relative to the hybrid vehicle 1. The counter shaft 21 supports an output gear 24 so as not to be rotatable relative to the hybrid vehicle 1. The output gear 24 is engaged with a ring gear 26 fixed to a differential case 25 of the differential gear 23.

[0025] When the hybrid vehicle 1 is traveling, the drive motor 4 is powered and generates power. The power generated by the drive motor 4 is transmitted to a ring gear 26 of a differential gear 23 via a drive motor gear 16, a counter gear 22, and an output gear 24, and is transmitted from the differential gear 23 to drive wheels 28 of the hybrid vehicle 1 via a drive shaft 27. This causes the drive wheels 28 to rotate, and the hybrid vehicle 1 travels forward or backward.

[0026] When the sum of the outputs required for the generator motor 3 and the drive motor 4 is smaller than the output of the battery, the hybrid vehicle 1 runs in EV mode. That is, the engine 2 is stopped, no power is generated by the generator motor 3, and power is supplied from the battery to the drive motor 4, which drives the drive motor 4.

[0027] On the other hand, when the total output required for the generator motor 3 and the drive motor 4 exceeds the output of the battery, the hybrid vehicle 1 runs as an HV. That is, the engine 2 is put into an operating state (firing) and the generator motor 3 is operated to generate electricity (regenerative operation), so that the power of the engine 2 is converted into AC power by the generator motor 3. The AC power from the generator motor 3 is then supplied to the drive motor 4, thereby driving the drive motor 4.

[0028] When starting the engine 2, the generator motor 3 is powered and the engine 2 is motored (cranked) by the generator motor 3. When the rotation speed of the crankshaft 11 of the engine 2 increases to a rotation speed required for firing due to motoring, the engine 2 fires when the spark plug of the engine 2 is sparked.

[0029] Furthermore, when the remaining charge of the battery falls below a predetermined level, regardless of whether the drive motor 4 is running or stopped, the generator motor 3 operates to generate electricity while the engine 2 is firing, and the battery is charged with the power generated by the generator motor 3. The battery is, for example, a battery pack made up of a combination of multiple lithium ion batteries.

[0030] When the hybrid vehicle 1 decelerates, the drive motor 4 is operated in a regenerative manner, and the power transmitted from the drive wheels 28 to the drive motor 4 is converted into electric power. At this time, the drive motor 4 acts as a resistance to the traveling drive system, and this resistance acts as a braking force (regenerative braking force) that brakes the hybrid vehicle 1. At this time, the battery is charged with the power generated by the drive motor 4.

[0031] The generator motor 3 and the drive motor 4 are housed in a unit case (not shown) together with a drive system including a differential gear 23, and are unitized as a transaxle. A mechanical oil pump 29 is provided in the unit case. The oil pump 29 is, for example, an internal gear pump, and has a pump gear in the pump case. The pump gear is supported on a pump shaft that rotates integrally with the crankshaft 11 of the engine 2 so as not to rotate relative to the pump shaft. When the crankshaft 11 rotates, the pump gear rotates integrally with the pump shaft, and the rotation of the pump gear causes oil accumulated at the bottom of the unit case to be sucked up by the oil pump 29, and the oil is discharged from the oil pump 29.

[0032] <Hybrid vehicle cooling system> FIG. 2 is a diagram illustrating the configuration of a cooling system of the hybrid vehicle 1. As shown in FIG.

[0033] Hybrid vehicle 1 is provided with an HV cooling system 32 that cools a transaxle and a PCU (Power Control Unit) 31, in addition to an engine cooling system (not shown) that cools engine 2. The configuration of PCU 31 will be described later.

[0034] The HV cooling system 32 includes an oil cooler (O / C) 33 for cooling (or heating) the oil in the unit case. The oil discharged from the oil pump 29 passes through the oil cooler 33, then passes through the generator motor 3 and drive motor 4, cooling the generator motor 3 and drive motor 4 in the process, and returns to the bottom of the unit case. In other words, the HV cooling system 32 employs an oil cooling method in which the generator motor 3 and drive motor 4 are cooled by oil circulating by the drive of the oil pump 29.

[0035] On the other hand, HV cooling system 32 employs a water-cooling method for cooling PCU 31 with coolant, and HV cooling system 32 includes electric water pump (W / P) 34 and radiator 35. One end and the other end of coolant circulation path 36 are connected to the discharge port and the suction port of electric water pump 34, respectively, and when electric water pump 34 is driven, coolant circulates through coolant circulation path 36. Radiator 35 is interposed in the middle of coolant circulation path 36, and coolant circulation path 36 passes through PCU 31 and oil cooler 33 in this order from the discharge port side of electric water pump 34 between radiator 35 and the suction port of electric water pump 34. The coolant circulating through coolant circulation path 36 releases heat to radiator 35 to lower its temperature, and then exchanges heat with PCU 31 to raise its temperature. In addition, in the oil cooler 33, heat is exchanged between the oil circulating by the drive of the oil pump 29 and the cooling water, causing the temperature of the oil to decrease and the temperature of the cooling water to increase.

[0036] <Hybrid vehicle control system> FIG. 3 is a block diagram showing the configuration of a control system for the hybrid vehicle 1. As shown in FIG.

[0037] The PCU 31 is a unit for controlling the driving of the generator motor 3 and the drive motor 4, and includes an inverter and a converter. The inverter is provided corresponding to each of the generator motor 3 and the drive motor 4, and during power running of the generator motor 3 and the drive motor 4, converts DC power to AC power and supplies the AC power to the generator motor 3 and the drive motor 4, and during regenerative operation (power generation operation) of the generator motor 3 and the drive motor 4, converts the AC power generated by the generator motor 3 and the drive motor 4 to DC power. During power running of the generator motor 3 and the drive motor 4, the converter boosts the DC power output from the battery and supplies it to the inverter. During regenerative operation of the generator motor 3 and the drive motor 4, the converter lowers the DC power output from the inverter and supplies it to the battery.

[0038] Further, the hybrid vehicle 1 is equipped with a plurality of ECUs (Electronic Control Units), and the PCU 31 is provided with an MGECU 41, which is one of the plurality of ECUs. Each ECU is provided with a microcontroller, and the microcontroller includes, for example, a CPU, a non-volatile memory such as a flash memory, and a volatile memory such as a dynamic random access memory (DRAM). The plurality of ECUs are connected to each other so as to enable two-way communication according to a controller area network (CAN) communication protocol.

[0039] The multiple ECUs include an HVECU 42. The HVECU 42 controls the generator motor 3 and the drive motor 4 via the PCU 31. In controlling the generator motor 3 and the drive motor 4, a torque command value for the generator motor 3 and a torque command value for the drive motor 4 are input from the HVECU 42 to the MGECU 41. The MGECU 41 controls the operation of the inverter and converter of the PCU 31 based on the torque command value input from the HVECU 42.

[0040] Furthermore, the objects controlled by the HVECU 42 include the electric water pump 34 of the HV cooling system 32. The HVECU 42 controls the drive of the electric water pump 34 through a flow rate control process to control the flow rate of the coolant flowing through the coolant circulation path 36. The flow rate control process will be described later.

[0041] To the HVECU 42, an MG1 thermistor 43, an MG2 thermistor 44, and a cooling water thermistor 45 are connected as sensors necessary for flow rate control processing.

[0042] The MG1 thermistor 43 is attached to the stator core of the generator motor 3, and outputs a detection signal corresponding to the temperature of the stator core. The HVECU 42 calculates the temperature of the stator core of the generator motor 3 from the detection signal of the MG1 thermistor 43, and detects the calculated stator core temperature as the temperature of the generator motor 3 (hereinafter referred to as the "MG1 temperature").

[0043] The MG2 thermistor 44 is attached to the stator core of the drive motor 4, and outputs a detection signal corresponding to the temperature of the stator core. The HVECU 42 calculates the temperature of the stator core of the drive motor 4 from the detection signal of the MG2 thermistor 44, and detects the calculated stator core temperature as the temperature of the drive motor 4 (hereinafter referred to as the "MG2 temperature").

[0044] The coolant thermistor 45 is provided to detect the temperature of the coolant circulating through the coolant circulation path 36 at a position that is an inlet of the coolant to the PCU 31, and outputs a detection signal corresponding to the temperature of the coolant at the inlet of the PCU 31. The HVECU 42 calculates the temperature of the coolant at the inlet of the PCU 31 from the detection signal of the coolant thermistor 45, and detects the calculated temperature as the temperature of the coolant circulating through the coolant circulation path 36 (hereinafter referred to as "coolant temperature").

[0045] <Flow control process> FIG. 4 is a flowchart showing the flow of the flow rate control process.

[0046] In the flow rate control process, first, the MG1 temperature and the MG2 temperature are acquired, and it is determined whether the MG1 temperature or the MG2 temperature is equal to or higher than a predetermined control start threshold (step S1). The MG1 temperature and the MG2 temperature are detected at regular intervals, and acquiring the MG1 temperature and the MG2 temperature means taking the most recent MG1 temperature and the MG2 temperature at the present time. The same applies to the cooling water temperature.

[0047] If both the MG1 temperature and the MG2 temperature are below the control start threshold (NO in step S1), normal control is performed (step S2). The relationship between the coolant temperature and the W / P request flow rate, which is the coolant discharge flow rate required for the electric water pump 34, is stored in the nonvolatile memory of the HVECU 42, and in normal control, the coolant temperature is acquired and the W / P request flow rate according to the coolant temperature is set based on the relationship stored in the nonvolatile memory. The relationship between the coolant temperature and the W / P request flow rate is as shown in FIG. 5. Based on this relationship, when the coolant temperature is below a certain lower limit temperature, the W / P request flow rate is set to the minimum discharge flow rate of the electric water pump 34, when the coolant temperature is above a certain upper limit temperature, the W / P request flow rate is set to the maximum discharge flow rate of the electric water pump 34, and when the coolant temperature is between the lower limit temperature and the upper limit temperature, the W / P request flow rate is set to a larger value as the coolant temperature increases. Then, the drive of the electric water pump 34 is controlled so that the discharge flow rate of the electric water pump 34 coincides with the W / P required flow rate.

[0048] When the cooling water temperature is low, such as when driving at high speed or when the outside air temperature is low, the W / P required flow rate is set to a small value, and the flow rate of the cooling water circulating through the cooling water circulation path 36 is limited to a low flow rate. If the flow rate of the cooling water is limited to a low flow rate during high output when the generating motor 3 and / or the driving motor 4 generate a large amount of heat, the amount of heat exchange between the oil and the cooling water in the oil cooler 33 is small, resulting in insufficient cooling of the oil, and the oil temperature (oil temperature) rises, and the MG1 temperature and the MG2 temperature rise. When the MG1 temperature exceeds a predetermined limit threshold, the output of the generating motor 3 is limited to a certain level or lower in order to protect the generating motor 3. When the MG2 temperature exceeds a predetermined output limit threshold, the output of the driving motor 4 is limited to a certain level or lower in order to protect the driving motor 4. The output limit threshold of the MG1 temperature and the output limit threshold of the MG2 temperature are set to a temperature value within a range of, for example, 105 to 145°C, and may be the same or different.

[0049] The control start threshold is set to a temperature value less than the output limit threshold, for example, in the range of 85 to 125°C. When at least one of the MG1 temperature and the MG2 temperature reaches the control start threshold (YES in step S1) while normal control is being performed, maximum flow control is started (step S3). In maximum flow control, the W / P required flow rate is set to the maximum discharge flow rate of the electric water pump 34. As a result, when the coolant temperature is less than the upper limit temperature, the flow rate of the coolant circulating through the coolant circuit 36 ​​increases, and the amount of heat exchanged between the oil and the coolant in the oil cooler 33 increases.

[0050] While maximum flow rate control is being performed, it is repeatedly determined whether or not both the MG1 temperature and the MG2 temperature have fallen below a predetermined control end threshold (step S4). The control end threshold is set to a temperature value equal to or lower than the control start threshold, for example, set to a temperature value within a range of 65 to 105°C. Maximum flow rate control is continued until both the MG1 temperature and the MG2 temperature fall below the control end threshold, and when both the MG1 temperature and the MG2 temperature fall below the control end threshold (YES in step S4), the maximum flow rate control is ended and normal control is started (step S2).

[0051] <Action and effect> As described above, the hybrid vehicle 1 employs an oil-cooling system in which the generator motor 3 and the drive motor 4 are cooled by oil, and the oil is cooled in the oil cooler 33 by heat exchange with the coolant flowing through the coolant circulation path 36. In normal control, the flow rate of the coolant is controlled to a flow rate according to the coolant temperature. When at least one of the MG1 temperature and the MG2 temperature becomes equal to or higher than the control start threshold value while normal control is being performed, the drive of the electric water pump 34 is controlled so that the flow rate of the coolant flowing through the coolant circulation path 36 increases to the maximum discharge flow rate of the electric water pump 34. This increases the amount of heat exchange between the oil and the coolant in the oil cooler 33. The increase in the amount of heat exchange between the oil and the coolant reduces the temperature of the oil, so that the MG1 temperature and the MG2 temperature can be prevented from becoming high enough to be equal to or higher than the output limit threshold value, and the output of the generator motor 3 and the drive motor 4 can be prevented from being limited for the protection of the generator motor 3 and the drive motor 4, respectively. As a result, the drivability can be improved when the generator motor 3 and the drive motor 4 are at high output, such as when the hybrid vehicle 1 is traveling at high speed.

[0052] <Modification> Although one embodiment of the present invention has been described above, the present invention can be embodied in other forms.

[0053] For example, in the above embodiment, the W / P required flow rate is increased to the maximum discharge flow rate of the electric water pump 34 when at least one of the MG1 temperature and the MG2 temperature reaches or exceeds the control start threshold value.

[0054] Without being limited thereto, when at least one of the MG1 temperature and the MG2 temperature becomes equal to or higher than the control start threshold, the W / P required flow rate may be raised to a predetermined value greater than the current W / P required flow rate within a range equal to or lower than the maximum discharge flow rate of electric water pump 34, and when both the MG1 temperature and the MG2 temperature are equal to or higher than the control start threshold, the predetermined value may be raised to a value greater than when one of the MG1 temperature and the MG2 temperature is equal to or higher than the control start threshold. In this way, when both the MG1 temperature and the MG2 temperature become equal to or higher than the control start threshold, the amount of heat exchanged between the oil and the coolant in oil cooler 33 can be further increased compared to when one of the MG1 temperature and the MG2 temperature is equal to or higher than the control start threshold.

[0055] Furthermore, when the MG1 temperature or the MG2 temperature becomes equal to or higher than the control start threshold, the W / P required flow rate may be increased to a larger value the greater the degree of increase in the MG1 temperature or the MG2 temperature until it becomes equal to or higher than the control start threshold. This allows the amount of heat exchanged between the oil and the cooling water in the oil cooler 33 to be increased significantly the greater the degree of increase in the MG1 temperature or the MG2 temperature, and effectively prevents the MG1 temperature and the MG2 temperature from reaching the output limit threshold.

[0056] In the case where a radiator fan for cooling the radiator 35 is provided, when at least one of the MG1 temperature and the MG2 temperature reaches or exceeds the control start threshold, the W / P required flow rate is increased, or instead of increasing the W / P required flow rate, the blowing capacity (rotation speed) of the radiator fan may be increased. This also increases the amount of heat exchanged between the oil and the coolant in the oil cooler 33.

[0057] The control start threshold for the MG1 temperature and the control start threshold for the MG2 temperature are not limited to being the same value, and may be set to different values.

[0058] In addition, not limited to the MG1 temperature and MG2 temperature, a variable having a correlation with the MG1 temperature and MG2 temperature, for example, the temperature of the oil cooling the generator motor 3 and the drive motor 4, may be detected, and when the oil temperature reaches or exceeds the control start threshold while normal control is being performed, the W / P required flow rate may be increased to a value greater than the current W / P required flow rate.

[0059] In the above embodiment, the hybrid vehicle 1 equipped with a series type hybrid system has been described, but the present invention can be applied to vehicles equipped with hybrid systems of types other than the series type, such as a series-parallel type. In a series-parallel type hybrid system, for example, an engine and a motor are connected to a planetary gear mechanism, and the power from the engine can be divided and distributed to the motor and the drive wheels, and the power from the engine and the power from the motor can be combined and transmitted to the drive wheels. In addition, the present invention is not limited to vehicles employing a hybrid system, and can be applied to electric vehicles (EVs) as long as the vehicles are equipped with a motor, and may also be applied to conventional vehicles that use an engine as a drive source.

[0060] In addition, various design modifications can be made to the above-described configuration within the scope of the claims. [Explanation of symbols]

[0061] 1: Hybrid vehicle (vehicle) 3: Generator motor (motor) 4: Drive motor (motor) 32:HV cooling system (cooling system) 36: Cooling water circulation path (cooling water channel) 42: HVECU (vehicle control device, flow control means, heat exchange amount increasing means)

Claims

1. A control device for use in a vehicle equipped with a generator motor, a drive motor, and a cooling system that cools oil by heat exchange with cooling water flowing through a cooling water passage, and cools the generator motor and the drive motor with the oil, a flow rate control means for controlling the flow rate of the cooling water to a flow rate corresponding to the temperature of the cooling water; a heat exchange amount increasing means for increasing an amount of heat exchange between the oil and the cooling water compared to when the flow rate control means is used, when a first variable having a correlation with the temperature of the generator motor is less than a first control start threshold and a second variable having a correlation with the temperature of the drive motor is less than a second control start threshold, causing the flow rate control means to perform control; When at least one of the following is true in a state in which the control by the flow rate control means is being performed: the first variable is equal to or greater than the first control start threshold value, or the second variable is equal to or greater than the second control start threshold value, the control by the flow rate control means is terminated and control by the heat exchange amount increasing means is started; A vehicle control device which, when control by the heat exchange amount increasing means is being performed, if the first variable falls below a first control termination threshold and the second variable falls below a second control termination threshold, terminates control by the heat exchange amount increasing means and starts control by the flow rate control means.

2. 2. The vehicle control device according to claim 1, wherein the heat exchange amount increasing means increases the flow rate of the cooling water to a predetermined value that is greater than a flow rate according to a temperature of the cooling water.

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