JP7375648B2 - Vehicle cooling system - Google Patents

Description

The present invention relates to a cooling device for a vehicle, and in particular, a cooling device for a vehicle that includes a motor, a high-voltage component, a cooling water flow path for the motor and the high-voltage component, and an oil flow path for oil that lubricates the inside of a transmission. Regarding.

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, motors and voltage converters (DCDC converters), which are high-voltage components for operating the motors, have become popular. In order to maintain the operating efficiency of a motor drive device including an inverter and the like, a technique is known in which a cooling water circuit is provided 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, and a flow path through which cooling water flows to cool a motor driving device such as a motor as a power source and its high-voltage components. A circuit is known that includes a flow path and a flow path through which oil for lubricating the inside of the transmission flows, and in which heat exchanges between the cooling water that cools the motor drive device and the oil that lubricates the inside of the transmission. There is. Patent Document 1 describes a circuit in which cooling water that has been cooled through a radiator flows through a heat exchanger that exchanges heat between the cooling water and transmission oil, a high voltage component for the motor, and the motor in this order. Disclosed.

Japanese Patent Application Publication No. 2015-001301

However, in a circuit like Patent Document 1, the cooling water cooled by the radiator flows through the heat exchanger, the high-voltage components, and the motor in this order, so the cooling water receives heat from the transmission oil in the heat exchanger. There is a problem in that the water temperature increases and the cooling efficiency of downstream high voltage components and motors decreases.

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

In order to achieve the above object, the present invention includes a motor as a power source of a vehicle, a high voltage component that supplies electric power to the motor, a cooling water flow path through which cooling water cools the motor and the high voltage components, A heat exchanger is installed in the oil flow path through which oil that lubricates the inside of the transmission flows, and in the cooling water flow path to exchange heat between the cooling water in the cooling water flow path and the oil in the oil flow path. and a radiator for cooling the cooling water, and the cooling water flow path includes a radiator, a high voltage component, a heat exchanger, and a heat exchanger so that the cooling water that has passed through the radiator flows in the order of the high voltage component, the heat exchanger, and the motor. It is characterized by being provided with an exchanger and a motor.

According to the present invention configured in this way, in the cooling water flow path, the cooling water that has passed through the radiator flows through the high-voltage components, the heat exchanger, and the motor in this order, so that the cooling water that has been cooled by the radiator first flows through the high-voltage components, then the heat exchanger, and then the motor. While the temperature increases due to heat received from the voltage components, the high voltage components can be effectively cooled. Next, the cooling water that has passed through the high-voltage parts flows through the heat exchanger, and as the high-voltage parts in particular generate a large amount of heat and the temperature of the cooling water becomes higher than the transmission oil temperature, the temperature of the cooling water increases with the transmission oil in the heat exchanger. The cooling water is cooled by heat exchange between the two, and the cooled cooling water flows through the downstream motor, thereby effectively cooling the motor. Therefore, it is possible to suppress a decrease in the cooling efficiency of high voltage components and the motor.

Further, in the present invention, preferably, the high voltage components are a voltage converter and an inverter, and the voltage converter and inverter are provided so that the cooling water flows in the order of the voltage converter and the inverter in the cooling water flow path. .
According to the present invention configured in this way, the voltage converter with a high cooling demand is preferentially cooled using low-temperature cooling water that has been cooled by flowing through the radiator, and then the inverter is cooled. By doing so, it is possible to more effectively suppress a decrease in the cooling efficiency of high voltage components and the motor.

Preferably, the present invention further includes an engine cooling water flow path through which cooling water for cooling the engine flows, and the cooling water flow path through which cooling water for cooling the motor and high-voltage components flows. It is a flow path independent of the channel.
According to the present invention configured in this way, the cooling water flow path for cooling the motor and high-voltage parts is provided as a separate circuit independent of the engine cooling water flow path, so that As a result, it is possible to more effectively suppress a decrease in the cooling efficiency of high-voltage components and the motor.

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

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. 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, with reference to FIG. 2, 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 will be described. . FIG. 2 is a schematic diagram showing a schematic configuration of a heat exchange circuit for cooling water and oil in a vehicle cooling system according to a first embodiment of the present invention.
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 .
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 second flow path 32a and the oil flowing through 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. This 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.
In this embodiment, the opening degree of the valve of the solenoid valve device 52 is adjusted according to the oil temperature detected by the oil temperature sensor 50, and the oil flow rate (first oil flow rate) flowing through the first heat exchanger 24 is adjusted. The solenoid valve device 52 is configured so that the oil flow rate (second oil flow rate) flowing through the second heat exchanger 26 can be adjusted.

For example, the solenoid valve device 52 causes the first oil flow rate to be greater than the second oil flow rate when the oil temperature is below a predetermined temperature (for example, 80°C), and on the other hand, when the oil temperature exceeds the predetermined temperature. The first oil flow rate can be made smaller than the second oil flow rate. In addition, as a modification, when the oil temperature exceeds a predetermined temperature, the first oil flow rate may be set to be equal to the second oil flow rate. The predetermined temperature is set to a temperature that can quickly raise the temperature of the oil to reduce the drive resistance of the transmission 8 and suppress an excessive rise in oil temperature.

Next, a vehicle cooling device according to a second embodiment of the present invention will be described with reference to FIGS. 3 and 4. FIG. 3 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. 4 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. 3, 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. 3, 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. 4, 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. The predetermined temperature is set to a temperature that can quickly raise the temperature of the oil to reduce the drive resistance of the transmission 8 and suppress an excessive rise in oil temperature.

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, in the cooling water flow path 32, the cooling water that has passed through the radiator 22 is transferred to the high voltage components 16, 18, and the second heat exchanger. First, the cooling water cooled by the radiator 22 receives heat from the high voltage components 16 and 18 and its temperature rises, and the high voltage components 16 and 18 are effectively cooled. I can do it. Next, the cooling water that has passed through the high-voltage parts 16 and 18 flows through the second heat exchanger 26, and as the high-voltage parts 16 and 18 in particular generate a large amount of heat and the temperature of the cooling water becomes higher than the transmission oil temperature, The cooling water is cooled by heat exchange with the transmission oil in the second heat exchanger 26, and this cooled cooling water flows through the downstream motor 6, thereby effectively cooling the motor 6. can. Therefore, a decrease in the cooling efficiency of the high voltage components 16, 18 and the motor 6 can be suppressed.

Further, according to the first and second embodiments, the voltage converter 16 with a high cooling demand is preferentially cooled using the low-temperature cooling water cooled by flowing through the radiator 22, and then the inverter By cooling 18, it is possible to suppress a decrease in the cooling efficiency of voltage converter 16, inverter 18, and motor 6.

Further, according to the first and second embodiments, the cooling water passage 32 for cooling the motor 6 and the high voltage components 16 and 18 is provided as a separate circuit independently of the cooling water passage 30 for the engine 4. Since it is provided, it is not affected by the cooling water that circulates in the engine 4 and reaches a relatively high temperature, and it is possible to effectively suppress a decrease in the cooling efficiency of the high voltage components 16, 18 and the motor 6. .

1,100 Vehicle cooling system 2 Power transmission system 4 Engine 6 Motor (motor drive device)
8 Transmission 10 Supercharger 12 Intercooler 14 EGR device 16 DCDC converter (voltage 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 2nd flow path 48 Flow rate adjustment valve/coolant solenoid valve 50 Oil temperature sensor 52 Solenoid valve 54 2WAY valve

Claims (3)

A motor as a power source for a vehicle,
A high voltage component that supplies power to the motor;
a cooling water flow path through which cooling water flows to cool the motor and the high voltage components;
An oil flow path through which oil lubricates the inside of the transmission,
a heat exchanger that is provided in the cooling water 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 radiator provided in the cooling water flow path for cooling the cooling water,
The cooling water flow path includes the radiator, the high voltage component, the heat exchanger, and the motor so that the cooling water that has passed through the radiator flows in the order of the high voltage component, the heat exchanger, and the motor. A cooling device for a vehicle, characterized in that it is provided with. The high voltage components mentioned above are voltage converters and inverters,
The vehicle cooling device according to claim 1, wherein the voltage converter and the inverter are provided so that the cooling water flows in the order of the voltage converter and the inverter in the cooling water flow path. Furthermore, it is equipped with a cooling water flow path for the engine, through which cooling water flows to cool the engine.
The vehicle cooling device according to claim 1 or 2, wherein the cooling water flow path through which cooling water for cooling the motor and the high voltage components flows is a flow path independent of the engine cooling water flow path. .

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