JP7375649B2 - Vehicle cooling system - Google Patents

Description

The present invention relates to a cooling device for a vehicle, and more particularly to a cooling device for a vehicle that includes a motor drive device, a cooling water flow path for the motor drive device, and an oil flow path for oil that lubricates the inside of a transmission.

In recent years, in so-called hybrid vehicles that use an engine and a motor as a power source, and so-called electric vehicles that use a motor as a power source, the operating efficiency of the motor and the motor drive device that includes the high-voltage parts that operate the motor has been increasing. In order to maintain this, it is necessary to cool the motor drive device.

For example, Patent Document 1 describes a flow path through which cooling water flows to cool an engine as a power source of a vehicle, a motor as a power source, and a motor drive device such as high voltage parts for operating the motor. A circuit is disclosed that includes a flow path through which cooling water flows for cooling, and a flow path through which oil flows to lubricate the inside of the transmission.

Japanese Patent Application Publication No. 2015-001301

However, in a circuit like Patent Document 1, when the temperature of the transmission oil is relatively high and the temperature of the cooling water is relatively low, the cooling water receives heat from the transmission oil in the heat exchanger, and the cooling water There is a problem in that the temperature rises, the motor drive device cannot be cooled down to a desired temperature, and the operating efficiency of the motor drive device cannot be maintained.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a vehicle cooling device that can suppress a decrease in cooling efficiency of a motor drive device.

In order to achieve the above object, the present invention provides a motor drive device, a cooling water flow path for the motor drive device through which cooling water for cooling the motor drive device flows, and an oil flow path through which oil circulates to lubricate the inside of a transmission. a heat exchanger installed in the oil flow path for exchanging heat between the cooling water in the cooling water flow path and the oil in the oil flow path; The present invention is characterized by comprising an oil flow rate adjustment device capable of adjusting the flow rate.

According to the present invention configured in this way, since the flow rate of oil flowing through the heat exchanger can be adjusted, the amount of heat exchanged between the oil and the cooling water can be adjusted to adjust the temperature of the cooling water. can. Therefore, even when the temperature of the transmission oil is relatively high and the temperature of the cooling water is low, the cooling water temperature can be adjusted by adjusting the amount of heat exchange, and a decrease in cooling efficiency of the motor drive device can be suppressed.

Further, in the present invention, preferably, the oil flow path includes a first flow path that circulates oil in the transmission to the transmission bypassing the heat exchanger, and a first flow path that circulates oil in the transmission to the transmission through the heat exchanger. and a second flow path for circulating the oil to the machine, and the oil flow rate adjustment device is provided in the second flow path of the oil flow path.
According to the present invention configured in this way, the oil flow path includes a first flow path that circulates the oil in the transmission to the transmission bypassing the heat exchanger, and a first flow path that circulates the oil in the transmission through the heat exchanger. Since the oil flow regulating device is provided in the second flow path, the oil flowing through the first flow path can ensure lubricating performance within the transmission. The oil flow rate adjusting device in the second flow path can accurately adjust the flow rate of oil flowing into the heat exchanger in the second flow path.

Preferably, the present invention further includes a control device that controls the oil flow rate adjustment device, and the control device controls the oil flow rate when the temperature of the oil in the oil flow path is higher than the temperature of the cooling water in the cooling water flow path. The oil flow rate adjusting device is controlled so that the flow rate of oil flowing through the heat exchanger is smaller than when the temperature of the oil in the cooling water flow path is lower than the temperature of the cooling water in the cooling water flow path.
According to the present invention configured in this way, when the temperature of the oil in the oil flow path is higher than the temperature of the cooling water in the cooling water flow path, the temperature of the oil in the oil flow path is higher than the temperature of the cooling water in the cooling water flow path. Since the oil flow rate adjustment device is controlled so that the flow rate of oil flowing through the heat exchanger is lower than when the temperature is low, even if the coolant temperature is relatively low and the oil temperature is high, the The amount of heat received by the motor can be reduced, thereby suppressing a decrease in the cooling efficiency of the motor drive device.

Further, in the present invention, preferably, when the temperature of the oil in the oil flow path is lower than the temperature of the cooling water in the cooling water flow path, the control device controls the temperature of the oil in the oil flow path to be the temperature of the cooling water in the cooling water flow path. The oil flow rate adjustment device is controlled so that the flow rate of oil flowing through the heat exchanger is greater than when the temperature is higher than .
According to the present invention configured in this way, when the temperature of the oil in the oil flow path is lower than the temperature of the cooling water in the cooling water flow path, the temperature of the oil in the oil flow path is lower than the temperature of the cooling water in the cooling water flow path. The oil flow adjustment device is controlled so that the flow rate of oil flowing through the heat exchanger is higher than when the cooling water temperature is relatively high and the oil temperature is low. By receiving heat from the cooling water, the cooling water can be cooled, and thereby the cooling efficiency of the motor drive device can be maintained or improved.

Further, in the present invention, preferably, the motor drive device includes a motor and a high voltage component for operating the motor, and the motor is provided downstream of the heat exchanger.
According to the present invention configured in this way, since the motor is provided on the downstream side of the heat exchanger, it is possible to more effectively suppress a decrease in the cooling efficiency of the motor of the motor drive device.

Preferably, the present invention further includes an engine cooling water flow path through which cooling water for cooling the engine flows, and the motor drive device cooling water flow path is a flow path independent of the engine cooling water flow path. be.
According to the present invention configured in this way, the cooling water flow path for cooling the motor drive device is provided as a separate circuit independently from the engine cooling water flow path, so that the cooling water flow path for cooling the motor drive device is provided as a separate circuit, and therefore the cooling water flow path for cooling the motor drive device is provided as a separate circuit independently from the engine cooling water flow path. As a result, it is possible to more effectively suppress a decrease in the cooling efficiency of the motor drive device.

According to the vehicle cooling device of the present invention, it is possible to suppress a decrease in the cooling efficiency of the motor drive device.

1 is a plan view showing a schematic configuration of a power source and a power transmission device of a vehicle to which a vehicle cooling device according to a first embodiment of the present invention is applied. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing a schematic configuration of a cooling water and oil heat exchange circuit of a vehicle cooling device according to a first embodiment of the present invention. FIG. 1 is a control block diagram of a control device for a vehicle cooling device according to a first embodiment of the present invention. It is a flowchart which shows the control process performed by the control apparatus of the cooling device for vehicles by 1st Embodiment of this invention. 5 is a time chart showing the relationship between the time change in oil flow rate controlled by the control device of the vehicle cooling device according to the first embodiment of the present invention, and the time change in cooling water temperature and oil temperature. FIG. 2 is a plan view showing a schematic configuration of a power source and a power transmission device of a vehicle to which a vehicle cooling device according to a second embodiment of the present invention is applied. It is a schematic diagram which shows the schematic structure of the cooling water and oil heat exchange circuit of the vehicle cooling device by 2nd Embodiment of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle cooling device according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

First, with reference to FIG. 1, a schematic configuration of a power transmission system of a vehicle to which a vehicle cooling device according to a first embodiment of the present invention is applied will be described. FIG. 1 is a plan view showing a schematic configuration of a power source and a power transmission device of a vehicle to which a vehicle cooling device according to a first embodiment of the present invention is applied.

As shown in FIG. 1, a power transmission system 2 of a vehicle to which a vehicle cooling device 1 according to a first embodiment of the present invention is applied includes an engine 4 and a motor 6 that are power sources, and a transmission that is a power transmission device. (transmission) 8. In this embodiment, the engine 4 is a six-cylinder longitudinally-mounted multi-cylinder engine, but it may be an engine with another number of cylinders, such as four cylinders.

The vehicle according to the present embodiment is a rear wheel drive vehicle (FR) in which a motor 6 is provided between an engine 4 and a transmission 8. It's a transmission. The power of the engine 4 and/or the motor 6 is transmitted to the transmission 8, and the power is transmitted to rear wheels (not shown) via a propeller shaft, a differential device (not shown), or the like. The transmission 8 is an automatic transmission, but may be a manual transmission. As a modification, the vehicle cooling device 1 according to the embodiment of the present invention can also be applied to a front wheel drive vehicle having a power transmission system of a horizontally mounted engine or a horizontally mounted transmission (not shown).

Next, as shown in FIG. 1, the engine 4 of the power transmission system 2 according to the present embodiment includes a supercharger (turbocharger) 10, an intake air (fresh air), and an interface for cooling intake gas including EGR gas. It includes a cooler 12 and an EGR device 14 that circulates exhaust gas to the intake side. In this embodiment, the supercharger 10 is a turbocharger that uses exhaust pressure, but it may also be an electric turbocharger or a mechanical supercharger.

Further, a DCDC converter (voltage converter/transformer) 16 and an inverter 18, which are high voltage components for operating the motor 6, are connected to the motor 6 of the power transmission system 2 according to the present embodiment. The voltage components 16 and 18 constitute a motor drive device.

On the vehicle front side of the engine 4 and motor 6, there is an air-cooled radiator (HT radiator) 20 (hereinafter referred to as a first radiator) for high-temperature cooling water that cools the cooling water that flows through the engine 4 and cools the engine 4 with the running wind. and low-temperature cooling water that is provided on the vehicle front side of the first radiator 20 and that flows through the DCDC converter 16, inverter 18, motor 6, and intercooler 12, and cools the cooling water that cools them with the running wind. An air cooling radiator (LT radiator) (hereinafter referred to as a second radiator) 22 is provided. Each radiator 20, 22 is a heat exchanger that exchanges heat between the running wind and cooling water.

Further, as shown in FIG. 1, the engine 4 is equipped with a first heat exchanger 24 (Automatic Transmission Fluid/Warmer-Cooler) that exchanges heat between engine cooling water and transmission oil, which will be described later. A second heat exchanger (Automatic Transmission Fluid/Warmer-Cooler) 26, which will be described later, exchanges heat between motor drive unit cooling water and transmission oil, is attached to each of the parts 6 and 6.

Next, referring to FIGS. 2 and 3, a schematic configuration of a circuit for heat exchange between cooling water and oil, including a cooling water flow path, an oil flow path, and a heat exchanger, of the vehicle cooling device according to the first embodiment of the present invention is shown. Explain. FIG. 2 is a schematic diagram showing a schematic configuration of a cooling water and oil heat exchange circuit of a vehicle cooling system according to the first embodiment of the present invention, and FIG. FIG. 3 is a diagram illustrating an example of the concept of adjusting the oil flow rate by the oil flow rate adjustment device of the cooling device.
First, as shown in FIG. 2, the vehicle cooling device 1 according to the first embodiment of the present invention includes an engine cooling water flow path (hereinafter referred to as a first cooling water flow path) 30, a motor drive device cooling water flow path (hereinafter referred to as a first cooling water flow path) 30, a cooling water flow path for a motor drive device (hereinafter referred to as a first cooling water flow path) , a second cooling water flow path) 32, and a transmission oil flow path (hereinafter referred to as an oil flow path) 34.

The first cooling water flow path 30 is a flow path through which the engine 4 and the oil cooler (OC) 28 that cools the engine oil in the engine 4 flow, and the cooling water that cools them flows.
The second cooling water flow path 32 flows through the DC/DC converter (DCDC) 16, the inverter (INV) 18, the motor (Motor) 6, and the intercooler (I/C) 12, and the cooling water that cools them flows. It is a flow path.
The oil flow path 34 is a flow path through which transmission oil that lubricates the inside of the transmission (TM) 8 flows.

The first cooling water flow path 30 will be explained in more detail.
The first cooling water passage 30 is provided with a water pump 40 for circulating cooling water within the first cooling water passage 30 .
The first cooling water flow path 30 has two branched flow paths. The first cooling water flow path 30 first includes a first flow path 30a through which cooling water flows through the water pump 40, the engine 4, the first radiator 20, and a thermostat (T/S) 42 as a temperature regulator of the cooling water. have The thermostat 42 is a valve that opens when the coolant flowing through the engine 4 is so high that it must be cooled by the radiator 20, allowing the coolant to flow through the radiator 20.

The first coolant flow path 30 further includes a second flow path 30b through which the coolant flows through the water pump 40, the first heat exchanger 24, the oil cooler 28, and the engine 4 in this order. The first heat exchanger 24 exchanges heat between the cooling water flowing through the second flow path 30b and the oil (transmission oil) flowing through the oil flow path 34.

Next, the second cooling water flow path 32 will be explained in more detail.
The second cooling water passage 32 is provided with a water pump 46 for circulating cooling water within the second cooling water passage 32 . Further, on the downstream side of the second radiator 22 and the upstream side of the water pump 46 in the second cooling water passage 30, a cooling water temperature sensor 47 that detects the temperature (water temperature) of the cooling water flowing through the second cooling water passage 30 is provided. It is provided. The coolant temperature sensor 47 may be provided at any position within the second coolant flow path 32 as long as it can detect the temperature of the coolant itself.

The second cooling water flow path 32 has two branched flow paths. The second cooling water passage 32 first has a first passage 32a through which cooling water flows through the water pump 46, the DCDC converter 16, the inverter 18, the second heat exchanger 26, and the motor 6 in this order. The second heat exchanger 26 exchanges heat between the cooling water flowing through the first flow path 32a and the oil flowing through the second flow path 34b of the oil flow path 34.

The second cooling water flow path 32 further branches from the first flow path 32a, and allows the cooling water to flow through a flow rate adjustment valve/coolant solenoid valve (Coolant Solenoid Valve) 48 that adjusts the flow rate of the cooling water, and the intercooler 12 in that order. , has a second flow path 32b that joins the first flow path 32a on the downstream side of the motor 6.

Next, the oil flow path 34 will be explained in more detail.
The transmission 8 is provided with an oil pump (not shown) for circulating oil within the transmission 8 and within the oil flow path 34. The oil pump (not shown) is a known oil pump that supplies transmission oil as lubricating oil/operating oil to power transmission components (gears, clutches, etc.) in the transmission 8.

The oil flow path 34 has two branched flow paths. The oil flow path 34 first has a first flow path 34 a that circulates between the transmission 8 and the first heat exchanger 24 . This first flow path 34a is also a flow path that bypasses the second heat exchanger 26.
The oil flow path 34 further branches from the first flow path 34a at a branch portion 34c, and circulates the oil that has passed through the transmission 8 and the first heat exchanger 24 to the second heat exchanger 26. 2 has a second flow path 34b that circulates from the heat exchanger 26 to the transmission 8.

Further, the oil flow path 34 is provided with an oil temperature sensor (SN) 50 that detects the temperature of the oil. The oil temperature sensor 50 may be provided at any position within the oil flow path 34 as long as it can detect the temperature of the oil itself.

Further, the second flow path 34b of the oil flow path 34 is provided with a solenoid valve device (SV) 52 that adjusts the flow rate of oil flowing to the second heat exchanger 26. This solenoid valve device 52 is an electromagnetic solenoid valve, and the opening degree of the valve can be adjusted by changing the duty ratio through on-off control.
The solenoid valve device 52 of this embodiment adjusts its valve opening degree to adjust the oil flow rate (first oil flow rate) flowing through the first heat exchanger 24 and the oil flow rate (first oil flow rate) flowing through the second heat exchanger 29. 2 oil flow rate) can be adjusted.

Next, the control details of the oil flow rate adjusting device 52 in the vehicle cooling device according to the first embodiment of the present invention will be explained with reference to FIGS. 3 to 5. FIG. 3 is a control block diagram of a control device for a vehicle cooling device according to the first embodiment of the present invention, and FIG. 4 is a control block diagram of a control device for a vehicle cooling device according to the first embodiment of the present invention. 5 is a flowchart showing the process, and FIG. 5 shows the relationship between the time change in the oil flow rate controlled by the control device of the vehicle cooling device according to the first embodiment of the present invention, and the time change in the cooling water temperature and the oil temperature. FIG.

First, with reference to FIG. 3, a control block of the control system included in the vehicle cooling device 1 according to the first embodiment of the present invention will be described.
As shown in FIG. 3, the control system 60 of the vehicle cooling device 1 according to this embodiment includes an ECU (control device) 62 that controls the flow rate regulating valve 48 and the like.
In this embodiment, the ECU 62 includes the cooling water temperature sensor 47 provided on the downstream side of the second radiator 22 in the second cooling water flow path 30 as described above, the output signal regarding the cooling water temperature from the SW 5, and the above-mentioned As described above, output signals relating to the temperature of the oil in the oil flow path 34 from the oil temperature sensor 50 and SW 10 provided on the downstream side of the transmission 8 in the oil flow path 34 are respectively input. Based on the output signals from the cooling water temperature sensor 47, SW5 and the oil temperature sensor 50, SW10, the ECU 62 controls the opening degree of the solenoid valve (oil flow rate adjustment valve) 52, as described later, to adjust the oil flow. By controlling the oil flow rate in the second flow path 34b of the passage 34, the flow rate of oil flowing through the second heat exchanger 26 is controlled.

The ECU 62 includes an ignition output signal (SW1) indicating a command to start the engine, an output signal related to the intake air amount from an air flow sensor SW2 provided in the intake passage of the engine 4, and an intake air temperature sensor SW3 provided in the intake passage. An output signal related to the intake air temperature from the intake air temperature, an output signal related to the intake pressure from the intake pressure sensor SW4 provided in the intake passage, an output signal related to the crank angle from the crank angle sensor SW6 provided on the crankshaft (4a) of the engine 4, An output signal related to the opening of the accelerator pedal from the accelerator opening sensor SW7, an output signal related to the intake side cam angle from the intake cam angle sensor SW8 provided on the intake camshaft (not shown), and an output signal related to the cam angle on the intake side from the intake camshaft (not shown). Output signals relating to the cam angle on the exhaust side from the exhaust cam angle sensor SW9 provided in the exhaust cam angle sensor SW9 are respectively input. The ECU 62 controls the fuel injection timing by controlling the injector 70 of the engine 4 based on the ignition signal SW1 and output signals from various sensors SW2 to SW9, and controls the fuel injection timing by controlling the spark plug 72 and the pre-chamber spark plug (PCP). 74 to control the ignition timing, the throttle valve 80, the intake side variable valve lift mechanism (intake electric S-VT) 16 and/or the injector 70 to control the air-fuel ratio, and the exhaust side variable valve lift mechanism (intake electric S-VT) 16 to control the air-fuel ratio. By controlling the variable valve lift mechanism (exhaust electric S-VT) 78 and the EGR valve 82, the flow rate of EGR gas recirculated to the intake side of the engine 4 is controlled.

Next, the content of the control process executed by the control unit (ECU) of the vehicle cooling device 1 according to the first embodiment of the present invention will be explained with reference to FIGS. 4 and 5.
As shown in FIG. 4, the ECU 62 first reads output signals (sensor values) from various sensors in S1. In this embodiment, an output signal related to the coolant temperature in the second coolant flow path 32 from the coolant temperature sensor 47 and SW5, and an output signal related to the oil temperature in the oil flow path 34 from the oil temperature sensor 50 and SW10 are input. be done.

Next, the process proceeds to S2, and it is determined whether the oil temperature in the oil flow path 34 read in S1 is higher than the cooling water temperature in the second cooling water flow path 32. If it is determined in S2 that the oil temperature is higher than the cooling water temperature (YES in S2), the process proceeds to S3, where the oil flow rate in the second flow path 34b of the oil flow path 34 is throttled (reduced). The opening degree of the solenoid valve (oil flow rate adjustment valve) 52 is controlled. That is, in this case, the duty ratio is changed by on-off control of the solenoid valve 52, and the opening degree of the valve is adjusted to be small. In this embodiment, through such control, the amount of heat received from the oil in the cooling water is reduced in the second heat exchanger 26, thereby suppressing a decrease in the cooling efficiency of the motor drive devices 6, 16, and 18. ing.

On the other hand, if it is determined in S2 that the oil temperature is lower than the cooling water temperature (NO in S2), the process proceeds to S4, and the solenoid valve 52 Controls the opening degree. That is, in this case, the duty ratio is changed by on-off control of the solenoid valve 52, and the opening degree of the valve is adjusted to be large. In this embodiment, by such control, the amount of heat received by the oil from the cooling water in the second heat exchanger 26 is increased, thereby cooling the cooling water, thereby controlling the motor driving devices 6, 16, 18. The cooling efficiency of the system is maintained or improved.

As shown in the time chart in Fig. 5, when the oil temperature (oil temperature) is higher than the cooling water temperature (water temperature), by reducing the oil flow rate in the second flow path 32b, the cooling water is not received from the oil. I try to reduce the amount of heat. When the oil temperature (oil temperature) becomes lower than the cooling water temperature (water temperature) during a certain time A, the amount of heat received from the oil by the cooling water is increased by increasing the oil flow rate in the second flow path 32b. I have to.

Next, a vehicle cooling device according to a second embodiment of the present invention will be described with reference to FIGS. 6 and 7. FIG. 6 is a plan view showing a schematic configuration of a power source and a power transmission device of a vehicle to which a vehicle cooling device according to a second embodiment of the present invention is applied, and FIG. 7 is a plan view showing a schematic configuration of a power source and a power transmission device according to a second embodiment of the present invention. FIG. 2 is a schematic diagram showing a schematic configuration of a heat exchange circuit for cooling water and oil of a vehicle cooling device.
Below, configurations that are different from the first embodiment will be mainly described. Regarding each configuration of the second embodiment, the same components are given the same reference numerals except for differences in arrangement relationship.

First, as shown in FIG. 6, a power transmission system 102 of a vehicle to which a vehicle cooling device 100 according to a second embodiment of the present invention is applied has an engine 4 that is a power source, similar to the first embodiment described above. and a motor 6, a transmission 8, a supercharger 10, an intercooler 12, an EGR device 14, a DCDC converter 16, an inverter 18, an air cooling radiator for high temperature cooling water (first radiator) 20, and a low temperature It includes a cooling water air cooling radiator (second radiator) 22, a first heat exchanger 24, and a second heat exchanger 26.

In this second embodiment, as shown in FIG. 6, the motor 6 is not arranged between the engine 4 and the transmission 8, but is arranged in parallel with the engine 4 in the vehicle width direction. In this second embodiment, a power transmission belt 5 is provided that connects a motor pulley 6b provided on an output shaft 6a of the motor and a crank pulley 4b provided on a crankshaft 4a of an engine 4, and the driving force of the motor 6 is is transmitted to the crankshaft 4a of the engine 4 via the belt 5. Power from the engine 4 and/or motor 6 is transmitted to the transmission 8 .

Next, as shown in FIG. 7, the vehicle cooling device 100 according to the second embodiment of the present invention has the engine 4 and the oil cooler 28 flowing through each other, similarly to the first embodiment described above. A motor through which cooling water flows through an engine cooling water flow path (first cooling water flow path) 30, a DCDC converter 16, an inverter 18, a motor 6, and an intercooler 12, and through which cooling water flows. There are mainly three flow paths/circuits: a drive device cooling water flow path (second cooling water flow path) 32 and a transmission oil flow path (oil flow path) 34 through which transmission oil that lubricates the inside of the transmission 8 flows. Equipped with

The first cooling water flow path 30 is configured similarly to the first embodiment described above. That is, the first cooling water flow path 30 is provided with a water pump 40 and has two branched flow paths. The first flow path 30a of the first coolant flow path 30 is a flow path through which cooling water flows through the water pump 40, the engine 4, the first radiator 20, and the thermostat 42 in this order. The passage 30b is a passage through which cooling water flows through the water pump 40, the first heat exchanger 24, the oil cooler 28, and the engine 4 in this order.

The second cooling water flow path 32 is configured similarly to the first embodiment described above. That is, the second cooling water flow path 32 is provided with a water pump 46 and has two branched flow paths. The first flow path 32a of the second cooling water flow path 32 is a flow path through which cooling water flows through the water pump 46, the DCDC converter 16, the inverter 18, the second heat exchanger 26, and the motor 6 in this order. 32b is a flow that branches from the first flow path 32a, flows the cooling water in this order through a flow rate adjustment valve 48 that adjusts the flow rate of the cooling water, and the intercooler 12, and joins the first flow path 32a on the downstream side of the motor 6. It is a road.

The oil flow path 34 according to the second embodiment is circulated between the transmission 8 and the first heat exchanger 24 by an oil pump (not shown) provided in the transmission 8, as in the first embodiment described above. a first flow path 34a; a second flow path 34b that branches from the first flow path 34a and circulates the oil that has passed through the transmission 8 and the first heat exchanger 24 to the second heat exchanger 26; has.

The oil flow path 34 according to the second embodiment is provided with a 2WAY valve (2Way-V) 54 instead of the solenoid valve device 52 of the first embodiment.
More specifically, in the oil flow path 34, a branch portion 34c where the second flow path 34b branches from the first flow path 34a includes oil flowing through the first flow path 34a and oil flowing through the second flow path 34b. A 2WAY valve (2Way-V) 54 is provided to completely separate the two. The 2WAY valve 54 of the second embodiment is a so-called thermostat, and opens and closes depending on the oil temperature in the oil flow path 34 to adjust the oil flow rate (first oil flow rate) flowing through the first heat exchanger 24 and the second The oil flow rate (second oil flow rate) flowing through the heat exchanger 26 is configured to be adjustable.

For example, when the oil temperature is below a predetermined temperature (e.g. 80° C.), the 2WAY valve 54 is closed so that the oil flows only to the first heat exchanger 24, whereas when the oil temperature exceeds the predetermined temperature In this case, the 2WAY valve 54 is opened so that oil flows through both the first heat exchanger 24 and the second heat exchanger 26.

Note that the power transmission system (102) of the vehicle of this second embodiment is the power transmission system 2 of the vehicle of the first embodiment described above, and in this power transmission system 2, the power transmission system (102) including the two-way valve 54 as described above. The circuit of the second embodiment may also be used. Similarly, the power transmission system (2) of the vehicle of the first embodiment described above is replaced with the power transmission system 102 of the vehicle of the second embodiment, and in this power transmission system 102, as described above, the solenoid valve 52 is The circuit of one embodiment may be configured.

Next, the main effects of the vehicle cooling device according to the embodiment of the present invention will be explained.
First, in the vehicle cooling devices 1 and 100 according to the first and second embodiments of the present invention, the oil flow path 34 has a gap between the cooling water in the second cooling water flow path 32 and the oil in the oil flow path 34. A second heat exchanger 26 for exchanging heat is provided, and oil flow rate adjusting devices 52 and 54 capable of adjusting the flow rate of oil flowing through the oil passage 34 are provided. Even when the temperature of the cooling water is high and the temperature of the cooling water is low, the cooling water temperature can be adjusted by adjusting the amount of heat exchange, thereby suppressing a decrease in the cooling efficiency of the motor drive devices 6, 16, and 18.

Further, according to the first and second embodiments, since the motor 6 is provided downstream of the second heat exchanger 26, a decrease in the cooling efficiency of the motor 6 can be effectively suppressed.

Further, according to the first embodiment, the oil flow path 34 includes a first flow path 34a that circulates oil in the transmission 8 to the transmission 8 bypassing the second heat exchanger 26, and a first flow path 34a that circulates oil in the transmission 8 to the transmission 8, bypassing the second heat exchanger 26. The solenoid valve 52 is provided in the second flow path 34b, so that the solenoid valve 52 is provided in the second flow path 34b. The solenoid valve 52 in the second flow path 34b can accurately adjust the flow rate of oil flowing into the second heat exchanger 26 in the second flow path 34b, while ensuring the lubrication performance within the transmission 8 by the oil flowing through. can.

Further, according to the first embodiment, when the temperature of the oil in the oil passage 34 is higher than the temperature of the cooling water in the cooling water passage 32, the temperature of the oil in the oil passage 34 is higher than the temperature of the cooling water in the cooling water passage 32. Since the solenoid valve 52 is controlled so that the flow rate of oil flowing through the second heat exchanger 26 is lower than when the temperature is lower than that of the oil temperature, even when the cooling water temperature is relatively low and the oil temperature is high, cooling is performed. The amount of heat that water receives from the oil can be reduced, and thereby a decrease in cooling efficiency of the motor drive devices 6, 16, and 18 can be suppressed.

Further, according to the first embodiment, when the temperature of the oil in the oil passage 34 is lower than the temperature of the cooling water in the cooling water passage 32, the temperature of the oil in the oil passage 34 is lower than the temperature of the cooling water in the cooling water passage 32. Since the solenoid valve 52 is controlled so that the flow rate of oil flowing through the second heat exchanger 26 is higher than when the temperature is higher than that of the second heat exchanger 26, when the cooling water temperature is relatively high and the oil temperature is low, the second Since the oil receives heat from the cooling water through the heat exchanger 26, the cooling water can be cooled, and thereby the cooling efficiency of the motor drive devices 6, 16, and 18 can be maintained or improved.

1, 100 Vehicle cooling system 2, 102 Power transmission system 4 Engine 6 Motor (motor drive device)
8 Transmission 10 Supercharger 12 Intercooler 14 EGR device 16 DCDC converter (high voltage parts, motor drive device)
18 Inverter (high voltage parts, motor drive device)
20 Engine cooling water radiator (first radiator)
22 Radiator for motor drive device (second radiator)
24 First heat exchanger 26 Second heat exchanger 30 Engine cooling water flow path 30a First flow path 30b of engine cooling water flow path Second flow path 32 of engine cooling water flow path Motor drive device cooling water flow path 32a Motor The first flow path 32b of the cooling water flow path for the drive device The first flow path 34 of the cooling water flow path for the motor drive device The first flow path 34a of the transmission oil flow path 34b The first flow path 34b of the transmission oil flow path Second flow path 47 Cooling water temperature sensor/water temperature sensor 48 Flow rate adjustment valve/coolant solenoid valve 50 Oil temperature sensor 52 Solenoid valve (oil flow rate adjustment device)
54 2WAY valve (oil flow adjustment device)
62 ECU (control unit)

Claims (6)

a motor drive device;
a motor drive device cooling water flow path through which cooling water for cooling the motor drive device flows;
An oil flow path through which oil that lubricates the inside of the transmission circulates;
a heat exchanger that is provided in the oil flow path and performs heat exchange between the cooling water in the cooling water flow path and the oil in the oil flow path;
A cooling device for a vehicle, comprising: an oil flow rate adjustment device provided in the oil flow path and capable of adjusting the flow rate of oil flowing through the oil flow path. The oil flow path includes a first flow path that circulates oil in the transmission to the transmission bypassing the heat exchanger, and a first flow path that circulates oil in the transmission to the transmission via the heat exchanger. and a second flow path for circulating the
The vehicle cooling device according to claim 1, wherein the oil flow rate adjustment device is provided in a second flow path of the oil flow path. Furthermore, it includes a control device that controls the oil flow rate adjustment device,
The control device controls the control device when the temperature of the oil in the oil flow path is higher than the temperature of the cooling water in the cooling water flow path, and when the temperature of the oil in the oil flow path is lower than the temperature of the cooling water in the cooling water flow path. 3. The vehicle cooling device according to claim 1, wherein the oil flow rate adjusting device is controlled so that the flow rate of oil flowing through the heat exchanger is smaller than the amount of oil flowing through the heat exchanger. The control device controls the control device when the temperature of the oil in the oil flow path is lower than the temperature of the cooling water in the cooling water flow path, and when the temperature of the oil in the oil flow path is higher than the temperature of the cooling water in the cooling water flow path. 4. The vehicle cooling device according to claim 3, wherein the oil flow rate adjusting device is controlled so that the flow rate of oil flowing through the heat exchanger is greater than the amount of oil flowing through the heat exchanger. The motor drive device includes a motor and high voltage components for operating the motor,
The vehicle cooling device according to any one of claims 1 to 4, wherein the motor is provided downstream of the heat exchanger. Furthermore, it is equipped with a cooling water flow path for the engine, through which cooling water flows to cool the engine.
6. The vehicle cooling device according to claim 1, wherein the motor drive device cooling water flow path is a flow path independent of the engine cooling water flow path.

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