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Title:
HEAT EXCHANGER AND VEHICLE HEAT EXCHANGE SYSTEM
Document Type and Number:
WIPO Patent Application WO/2020/136092
Kind Code:
A2
Abstract:
A vehicle heat exchange system is provided, which allows for reduction in the size of a heat exchanger and effective utilization of exhaust heat from a motor. A heat exchanger is provided in which a first flow channel (second, fourth, and sixth layers) and a third flow channel (first, third, fifth, and seventh layers) are alternately arranged in a direction of stacking from a partition wall 56 at one end to a midway partition wall 5m; and a second flow channel (eighth, tenth, and twelfth layers) and the third flow channel (ninth, eleventh, and thirteenth layers) are alternately arranged in the direction of stacking from the midway partition wall 56m to a partition wall at the other end 54, the third flow channel (first, third, fifth, and seventh layers) and the third flow channel (ninth, eleventh, and thirteenth layers) are in communication with each other so as to form a continuous flow channel. A vehicle heat exchange system includes a first heat exchanger that performs heat exchange between a first medium for use in cooling of an internal combustion engine and a third medium for use in lubrication of a transmission and/or cooling of a motor, and a second heat exchanger that performs heat exchange between a second medium for use in cooling of an inverter and the third medium.

Inventors:
ARIYAMA MASAHIRO (JP)
ISODA KATSUHIRO (JP)
YAMASHITA KENJI (JP)
Application Number:
EP2019/086420
Publication Date:
July 02, 2020
Filing Date:
December 19, 2019
Export Citation:
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Assignee:
MAHLE FILTER SYSTEMS JP CORP (JP)
MAHLE INT GMBH (DE)
International Classes:
F01M5/00; B60K11/02; F01P3/12; F28D9/00; H05K7/20
Foreign References:
JP2011098628A2011-05-19
JP2012047309A2012-03-08
Attorney, Agent or Firm:
BRP RENAUD UND PARTNER MBB (DE)
Download PDF:
Claims:
BO

What is claimed is:

1. A heat exchanger comprising a plurality of partition walls stacked on top of one another, the partition walls defining, between pairs of adjacent ones of the partition walls, a first flow channel in which a first medium for use in cooling of an internal combustion engine flows, a second flow channel in which a second medium for use in cooling of an inverter flows, and a third flow channel in which a third medium for use in lubrication of a transmission and/or cooling of a motor flows, wherein the first flow channel, the second flow channel, and the third flow channel are isolated from each other,

the first flow channel and the third flow channel being alternately arranged in a direction of stacking of the partition walls from a partition wall at one end to a midway partition wall, the second flow channel and the third flow channel being alternately arranged in the direction of stacking from the midway partition wall to a partition wall at another end, and

the third flow channel adjacent to the first flow channel and the third flow channel adjacent to the second flow channel being in communication with each other so as to form a continuous flow channel.

2. A vehicle heat exchange system comprising:

a first heat exchanger that performs heat exchange between a first medium for use in cooling of an internal combustion engine and a third medium for use in lubrication of a transmission and/or cooling of a motor; and

a second heat exchanger that performs heat exchange between a second medium for use in cooling of an inverter and the third medium.

3. The vehicle heat exchange system according to claim 2, wherein the third medium passes through the second heat exchanger after passing through the first heat exchanger.

4. The vehicle heat exchange system according to claim 2 or 3, further comprising: a first medium switch valve that enables selective switching between a first path that supplies the first medium after cooling the internal combustion engine to the first heat exchanger via an internal combustion engine radiator and a second path that supplies the first medium after cooling the internal combustion engine directly to the first heat exchanger; and

a control unit that controls the first medium switch valve such that the first path is selected in response to the first medium being in a predetermined high- temperature state, and the second path is selected in response to the first medium being not in the predetermined high-temperature state.

5. The vehicle heat exchange system according to any one of claims 2 to 4, further comprising a second medium switch valve that enables selective switching between a third path that supplies the second medium having passed through the second heat exchanger to the inverter via an inverter radiator and a fourth path that supplies the second medium having passed through the second heat exchanger directly to the inverter, wherein, the control unit controls the second medium switch valve such that the third path is selected when the control unit determines that the second medium and/or the third medium are each in a predetermined high-temperature states and the fourth path is selected when the control unit determines that the second medium and/or the third medium are not each in a high-temperature states.

6. The vehicle heat exchange system according to any one of claims 2 to 5, wherein the heat exchanger according to claim 1 is used as a heat exchanger having functionality of the first heat exchanger and the second heat exchanger, and

the first medium is made to flow in the first flow channel, the second medium is made to flow in the second flow channel, and the third medium is made to flow in the third flow channel, respectively.

Description:
HEAT EXCHANGER AND VEHICLE HEAT EXCHANGE SYSTEM

BACKGROU ND OF TH E I NVENTION

Field of the I nvention

[0001]

The present disclosure relates to a heat exchanger that performs heat exchange between three types of liquids and a vehicle heat exchange system that performs heat exchange of an internal combustion engine, an inverter, a motor, etc. of a hybrid vehicle or the like.

Description of the Related Art

[0002]

I n recent years, hybrid vehicles (HEV) have been widely introduced to seek improved fuel efficiency. As HEVs run with both an internal combustion engine and a motor as drive sources, effective utilization of their exhaust heat has become a challenge for realizing further improvement in fuel efficiency. And various solutions to this challenge have been disclosed (for example, see Japanese Patent Laid-Open No. 2011-98628).

[0003]

According to a vehicle heat exchange system illustrated in Japanese Patent Laid-Open No. 2011-98628, in a vehicle heat exchange system that includes an engine cooling water circuit that cools an engine, a driving inverter that converts a DC current into an AC current and supplies it to a driving motor, and an HV cooling circuit that cools the driving motor, exhaust heat produced from the driving inverter and the driving motor is utilized to warm up the engine by warming engine cooling water through performing heat exchange between the engine cooling water and HV cooling water.

[0004]

However, as the number of other types of exhaust heat has been increasing in modern vehicle heat exchange systems, utilization of the exhaust heat is not sufficient in existing systems. For example, in response to increase in the amount of heat generated from a motor as a result of increase in the output of the motor as well as reduction in the size of the motor, the number of hybrid vehicles is increased which are configured to apply automatic transmission fluid (ATF) for use in lubrication of a decelerator (automatic transmission) to a power generation motor and/or a driving motor within a transmission case (gear case) so as to oil-cool these motors (for example, see Japanese Patent Laid-Open No. 2012-47309), but the status quo is that the exhaust heat produced from these motors in such a configuration is not utilized effectively.

[0005]

I n the meantime, in vehicles, space saving has been achieved for the purpose of securing a living space and optimizing space distribution, and there has been a demand for reduction in the sizes of various devices and electrical components for vehicles. Accordingly, reduction in the size of heat exchangers used in vehicle heat exchange systems is also desirable.

SUMMARY OF THE I NVENTION

[0006] The present disclosure is related to providing a vehicle heat exchange system capable of effectively utilizing exhaust heat produced from motors such as a power generation motor and a driving motor.

In addition, the present disclosure is related to achieving reduction in the size of a heat exchanger.

[0007]

In accordance with one aspect of the present disclosure, a heat exchanger is provided which includes a plurality of partition walls stacked on top of one another, the partition walls defining, between pairs of adjacent ones of the partition walls, a first flow channel in which a first medium for use in cooling of an internal combustion engine flows, a second flow channel in which a second medium for use in cooling of an inverter flows, and a third flow channel in which a third medium for use in lubrication of a transmission and/or cooling of a motor flows, wherein the first flow channel, the second flow channel, and the third flow channel are isolated from each other, the first flow channel and the third flow channel are alternately arranged in a direction of stacking of the partition walls from a partition wall at one end to a midway partition wall, the second flow channel and the third flow channel are alternately arranged in the direction of stacking from the midway partition wall to a partition wall at another end, and the third flow channel adjacent to the first flow channel and the third flow channel adjacent to the second flow channel are in communication with each other so as to form a continuous flow channel.

[0008]

According to the aspect of the present disclosure directed to the heat exchanger described above, with regard to a so-called three-phase type heat exchanger which performs heat exchange between three types of liquids, reduction in size can be achieved while maintaining its functions. The heat exchanger of this aspect is used in particular in a preferable manner in an aspect of the present disclosure directed to a vehicle heat exchange system which will be described later.

[0009]

Meanwhile, according to another aspect of the present disclosure, a vehicle heat exchange system is provided which includes a first heat exchanger that performs heat exchange between a first medium for use in cooling of an internal combustion engine and a third medium for use in lubrication of a transmission and/or cooling of a motor, and a second heat exchanger that performs heat exchange between a second medium for use in cooling of an inverter and the third medium.

[0010]

According to the aspect of the present disclosure, in an EV driving mode or the like after the start-up and before the internal combustion engine starts to operate, in which the temperature of the first medium is low, the heat exchange between the first medium and the third medium is performed by the first heat exchanger, so that warm up of the internal combustion engine can be promoted. By virtue of this, exhaust heat produced from the transmission and/or the motor can be effectively utilized.

[0011]

At this point, it is preferable that the heat exchange system be configured such that the third medium passes through the second heat exchanger after passing through the first heat exchanger. Since it is ensured that the third medium passes through the second heat exchanger after passing through the first heat exchanger, the temperature of the third medium supplied to the second heat exchanger can be lowered in advance to some extent, by virtue of which the temperature rise of the second medium can be suppressed, so that, for example, reduction in the size of an inverter radiator can be achieved.

[0012]

Also, it is preferable that the system further includes a first medium switch valve that enables selective switching between a first path that supplies the first medium after cooling the internal combustion engine to the first heat exchanger via an internal combustion engine radiator and a second path that supplies the first medium after cooling the internal combustion engine directly to the first heat exchanger; and a control unit that controls the first medium switch valve such that the first path is selected in response to the first medium being in a predetermined high-temperature state, and the second path is selected in response to the first medium being not in the predetermined high-temperature state.

[0013]

According to the above-described aspect, when the EV driving mode or the like after the start-up and before the internal combustion engine starts to operate and the temperature of the first medium is not in the predetermined high-temperature state, then the heat exchange between the first medium and the third medium is performed by the first heat exchanger, so that warm-up of the internal combustion engine can be promoted. As a result of this, exhaust heat produced from the motor can be effectively utilized. Meanwhile, when the temperature of the first medium is in the predetermined high-temperature state, for example, when the internal combustion engine is gradually warmed and the shift is made to an HV driving mode, then the heat exchange between the first medium that has been cooled by the internal combustion engine radiator and the third medium is performed by the first heat exchanger and the heat exchange between the second medium and the third medium is performed by the second heat exchanger so as to perform cooling of the third medium, so that the heat exchange of the third medium is performed in a distributed manner by the first heat exchanger and the second heat exchanger and thereby, the load on the second medium is reduced. For this reason, for example, since the load upon the inverter radiator can be reduced, which can contribute to reduction in the size of the inverter radiator.

[0014]

Also, it is preferable that the system further includes a second medium switch valve that enables selective switching between a third path that supplies the second medium having passed through the second heat exchanger to the inverter via the inverter radiator and a fourth path that supplies the second medium having passed through the second heat exchanger directly to the inverter, wherein the control unit controls the second medium switch valve such that the third path is selected when the control unit determines that the second medium and/or the third medium are each in a predetermined high-temperature states and the fourth path is selected when the control unit determines that the second medium and/or the third medium are not each in a predetermined high-temperature states.

[0015]

According to the above-described aspect, when the EV driving mode or the like after the start-up and before the internal combustion engine starts to operate and the second medium and/or the third medium are not each in predetermined high- temperature states, then, without involvement of the inverter radiator, the second medium directly supplied to the inverter and thereby warmed and the third medium are subjected to heat exchange by the second heat exchanger. By doing so, the temperature rise of the third medium can be promoted, which contributes to friction reduction of a drive unit such as the motor and the like.

[0016]

Meanwhile, when the second medium and/or the third medium are each in a predetermined high-temperature states, then the inverter is cooled by the second medium that has been cooled by the inverter radiator, so that the temperature of the second medium is suppressed to a lower level, and, in this state, the second medium and the third medium are subjected to the heat exchange by the second heat exchanger. Accordingly, the third medium whose temperature has become high can be effectively cooled.

[0017]

Further, the aforementioned three-phase type heat exchanger which is the aspect of the present disclosure can be used as the heat exchanger that has the functions of both of the first heat exchanger and the second heat exchanger.

I n this case, it should be ensured that the first medium flows in the first flow channel, the second medium flows in the second flow channel, and the third medium flows in the third flow channel.

[0018]

When the heat exchanger which is the aspect of the present disclosure is used on the vehicle heat exchange system which is the aspect of the present disclosure, two heat exchanger can be integrated into one single unit and its size can be reduced while maintaining the functions of the system, which in turn achieves smaller installation space of the system.

[0019]

Note that the aforementioned third medium is an oil-based fluid for use in lubrication of the transmission and cooling of the motor and it is preferable that the third medium is automatic transmission fluid. I n automatic transmission of vehicles, oil-based automatic transmission fluids (ATF) or continuously variable transmission fluids (CVTF) are used. For this reason, as the third medium different than the first medium and the second medium in which in general water-based coolant is used, automatic transmission fluids such as ATFs and CVTFs can also be utilized also for this purpose without using new liquid, and the oil-based medium excellent in its electrical insulation property can be adopted as the coolant for the electric systems.

[0020]

According to the vehicle heat exchange system of the present disclosure, it is made possible to provide a vehicle heat exchange system that can effectively utilize the exhaust heat produced from the transmission and the motors.

Also, according to the heat exchanger of the present disclosure, reduction in the size can be achieved. The heat exchange of the present disclosure can be in a preferred manner used in the vehicle heat exchange system of the present disclosure.

BRI EF DESCRI PTION OF THE DRAWI NGS

[0021] FIG. 1 is a block diagram that schematically illustrates an overall configuration of a vehicle heat exchange system in accordance with a first embodiment illustrating an example of the present disclosure;

FIG. 2 is a block diagram that illustrates a state where operation takes place in an EV driving mode in the vehicle heat exchange system in accordance with the first embodiment depicted in FIG. 1;

FIG. 3 is a block diagram that illustrates a state where the operation takes place in an HV driving mode in the vehicle heat exchange system in accordance with the first embodiment depicted in FIG. 1;

FIG. 4 is a graph that shows a relationship between elapsed time since engine start-up and temperatures of media circulating in individual circuits and the engine in the vehicle heat exchange system in accordance with the first embodiment depicted in FIG. 1;

FIG. 5 is a block diagram that schematically illustrates an overall configuration of a vehicle heat exchange system in accordance with a second embodiment illustrating an example of the present disclosure;

FIG. 6 is a block diagram that illustrates a state where operation takes place in the EV driving mode in the vehicle heat exchange system in accordance with the second embodiment depicted in FIG. 5;

FIG. 7 is a block diagram that illustrates a state where the operation takes place in the EV driving mode when the temperature of inverter cooling water has risen in the vehicle heat exchange system in accordance with the second embodiment depicted in FIG. 5;

FIG. 8 is a block diagram that illustrates a state where the operation takes place in the HV driving mode in the vehicle heat exchange system in accordance with the second embodiment depicted in FIG. 5;

FIG. 9 is a graph that shows a relationship between elapsed time since engine start-up and temperatures of media circulating in individual circuits and the engine in the vehicle heat exchange system in accordance with the second embodiment depicted in FIG. 5;

FIG. 10 is a block diagram that schematically illustrates an overall configuration of a vehicle heat exchange system in accordance with a third embodiment illustrating an example of the present disclosure;

FIG. 11 is a perspective view of a heat exchanger in accordance with an embodiment illustrating an example of the present disclosure, which is used in the third embodiment depicted in FIG. 10;

FIG. 12 is a bottom view of the heat exchanger in accordance with an embodiment illustrating an example of the present disclosure, which is used in the third embodiment depicted in FIG. 10; and

FIG. 13 is schematic configuration diagram for explanation of an internal structure of the heat exchanger in accordance with an embodiment illustrating an example of the present disclosure, which is used in the third embodiment depicted in FIG. 10.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, a vehicle heat exchange system of the present disclosure will be specifically described with reference to three preferred embodiments. With regard to a heat exchanger of the present disclosure, explanations will be provided in the context of a third embodiment.

[0023]

(First Embodiment)

FIG. 1 is a block diagram that schematically illustrates an overall configuration of a vehicle heat exchange system in accordance with a first embodiment illustrating an example of the present disclosure. The arrow lines in FIG. 1 each represents the flow of a medium in a circulation circuit for each of heat exchange media.

[0024]

As illustrated in FIG. 1, the vehicle heat exchange system in accordance with the present embodiment includes three cooling (circulation) circuits, i.e., an engine cooling circuit (first medium cooling circuit) 10 for performing cooling of an engine 11 which is an internal combustion engine, an inverter cooling circuit (second medium cooling circuit) 20 for performing cooling of an inverter 21, and an ATF cooling circuit (third medium cooling circuit) 30 for cooling automatic transmission fluid (ATF) of a drive unit 39 which incorporates a decelerator (automatic transmission) 31, a driving motor (motor) 36, and a power generation motor (motor) 35.

[0025]

Also, in the vehicle heat exchange system in accordance with the present embodiment, two heat exchangers, i.e., a first heat exchanger 1 and a second heat exchanger 2, for mutual heat exchange of the heat of the media (cooling water, ATF) flowing in the individual cooling circuits are provided across two circuits.

[0026]

The engine cooling circuit 10 includes, in addition to the engine 11, an electrically-powered engine pump 12 for pumping and circulating engine cooling water (first medium) to the engine cooling circuit 10, a heater core 17 for generating warm air during heating operation of a car air conditioner, a throttle body 18 including a throttle valve, an engine radiator (internal combustion engine radiator) 13 for cooling of the circulating engine cooling water by heat dissipation, a water channel switch valve (first medium switch valve) 16 that switches on and off the supply of the engine cooling water to the engine radiator 13, and a water temperature meter (T i) 14 that measures the water temperature of the engine cooling water that has cooled the engine 11. In this engine cooling circuit 10, the engine cooling water circulates as depicted by the flow indicated by the dotted arrows in FIG. 1.

[0027]

The engine cooling water pumped from the electrically-powered engine pump 12 is first sent to a water jacket formed inside the engine 11 via the first heat exchanger 1. Here, the engine cooling water is used as a coolant for the engine 11. At the downstream side of the engine 11 in the engine cooling circuit 10, the water channel is split into three portions, which are individually connected to the heater core 17, the throttle body 18, and the water channel switch valve 16, respectively.

[0028]

The water channel switch valve 16 is an electromagnetic directional switching valve, and is configured to be capable of selective switching between a first path A in which the engine cooling water that has passed through the engine 11 flows toward the first heat exchanger 1 after having passed through the engine radiator IB and a second path B in which the engine cooling water that has passed through the engine 11 directly flows toward the first heat exchanger 1. As the engine radiator 13 provided in the engine cooling circuit 10, the one having a larger size and higher cooling capacity than an inverter radiator 23 provided in an inverter cooling circuit 20 is adopted. In the present embodiment, since the electrically-powered engine pump 12 is arranged before the first heat exchanger 1, the engine cooling water in any case flows toward the first heat exchanger 1 via the electrically-powered engine pump 12.

[0029]

It should be noted that, in the present disclosure, the pump that generates a liquid flow in the cooling circuits (not only the engine cooling circuit 10 but all of the three cooling circuits) may be arranged anywhere in the path. In the present embodiment, the position where the pump is arranged is one of suitable examples, and is not limited in particular in the present disclosure. Also, as is the case with the engine cooling circuit 10 in the present embodiment, even when the electrically- powered engine pump 12 resides between the engine (internal combustion engine) 11 and the first heat exchanger 1, it is assumed that the engine 11 and the second heat exchanger 2 are directly coupled to each other and it is contemplated here that the state is entered where "the first medium (engine cooling water) that has cooled the internal combustion engine (engine 11) is directly supplied to the second heat exchanger (2)."

[0030]

It is ensured that the engine cooling water that has been made to pass through the path A or the path B selectively by the water channel switch valve 16 merges with the engine cooling water that has flown through the heater core 17 and the throttle body 18 and then flows back to the electrically-powered engine pump 12, and the engine cooling circuit 10 is formed as a closed circuit.

[0031]

The vehicle heat exchange system of the present embodiment is controlled by an ECU (electronic control unit; control unit) 40. The ECU 40 is configured as a computer unit that includes a central processing unit (CPU) that executes various calculation processes related to the control of this heat exchange system, a read-only memory (ROM) that stores control programs and data, a random access memory (RAM) that temporarily stores calculation results of the CPU and external input information, and an input/output port (I/O) that mediates external data

inputs/outputs.

[0032]

With regard to the ECU 40, a result of detection of the engine cooling water temperature measured by the water temperature meter (Ti) 14 is input via the input port. Also, with regard to the ECU 40, a control signal is output from the ECU 40 via the output port to the water channel switch valve 16 in accordance with this result of detection as well as the status of operation or stoppage of the engine 11 separately determined by the ECU 40 itself, and by controlling this, the operation of the vehicle heat exchange system of the present embodiment is managed.

[0033]

It should be noted that, with regard to the ECU 40, in addition to those that have been mentioned above, results of detection of the temperature of inverter cooling water, the temperature of the ATF in the drive unit 39, the outside

temperature, the traveling speed of the vehicle, and the like are input, and, with these conditions taken into account, various devices and components may be more precisely controlled such as the electrically-powered engine pump 12, an electrically-powered inverter pump 22, an ATF pump 32, and the like as well as the water channel switch valve 16.

[0034]

The inverter cooling circuit 20 includes, in addition to the inverter 21, the electrically-powered inverter pump 22 for pumping and circulating the inverter cooling water (second medium) to the inverter cooling circuit 20, and an inverter radiator 23 for cooling the inverter cooling water by heat dissipation. In this inverter cooling circuit 20, the inverter cooling water circulates as depicted by the flow indicated by the solid arrows in FIG. 1. Specifically, the inverter cooling water passes through the inverter radiator 23, the inverter 21, the second heat exchanger 2, and the electrically- powered inverter pump 22 in this order, and the inverter cooling circuit 20 is formed as a closed circuit.

[0035]

The ATF cooling circuit 30 is a circuit that pumps the ATF (third medium) inside the drive unit 39 to the first heat exchanger 1 and the second heat exchanger 2 by the ATF pump 32 so as to make the ATF circulate for cooling. Inside the drive unit 39, the ATF pump 32, the decelerator 31, the driving motor 36, the power generation motor 35, and the like are incorporated.

[0036]

In the drive unit 39, the ATF is brought up by the rotation of one of gears of the decelerator (transmission) 31 and supplied to the decelerator 31, and serves as a lubricant of the individual gears of the decelerator 31. Also, it is ensured that the ATF that has been pumped up by the ATF pump 32 is pumped to the ATF cooling circuit 30, in addition to which the ATF is made to flow to be applied to the driving motor 36 and the power generation motor 35. The ATF supplied to the decelerator 31 is used for the original function of the ATF. On the other hand, the ATFs that have been made to flow to be applied to the driving motor 36 and the power generation motor 35 function to cool these motors.

[0037]

In the ATF cooling circuit 30, the ATF circulates as depicted by the flow indicated by the dash-dotted arrows in FIG. 1. Specifically, the ATF that has been pumped out of the drive unit 39 by the ATF pump 32 flows through the second heat exchanger 2 after having flowed through the first heat exchanger 1 and then flows back to the drive unit 39, so that the ATF cooling circuit 30 is formed as a closed circuit.

[0038]

The two heat exchangers including the first heat exchanger 1 and the second heat exchanger 2 are a heat exchanger each configured to perform liquid-to-liquid heat exchange. More specifically, it is a device which separates the flow channels of two liquids from each other by a partition wall made of a material with high thermal conductivity (for example, metal such as aluminum and stainless steel) so as to transfer heat from the high-temperature liquid to the low-temperature liquid across the partition wall and thereby realize the heat exchange. The two flow channels are sealed from each other such that the liquids are not mixed with each other, and it is ensured that different liquids are allowed to pass through the one flow channel and the other flow channel so as to realize heat exchange between these two liquids. By increasing the area of the partition wall between the two flow channels and increasing the thermal conductivity of the partition wall (including thinning), the heat exchange efficiency can be improved.

There is no limitation in particular in relation to these heat exchangers, and conventionally well-known ones can be used as a heat exchanger which performs the liquid-to-liquid heat exchange.

[00B9]

Next, a state of operation of the vehicle heat exchange system in accordance with the present embodiment will now be described for each of the vehicle's driving mode. In the following description, an example is described which is implemented based on a series-parallel hybrid scheme having an EV driving mode in which the engine 11 is stopped and the driving only relies upon the driving motor 36 and an HV driving mode in which the engine 11 operates to drive the power generation motor 35 whose electrical power is used to operate the driving motor 36 so that the driving only relies upon the driving motor 36 or the driving takes place based on both of the outputs of the driving motor 36 that is made to operate in the same manner and the outputs of the engine 11.

[0040]

In addition to this, the temperature change of the media circulating in the individual circuits will be explained using a graph in FIG. 4. Note that FIG. 4 is the graph in which the expected values are plotted, wherein the horizontal axis indicates the elapsed time since the start-up (time 0) and the vertical axis indicates the temperatures of the individual media and the engine 11. In order to make it easier to understand, the graphs of the engine cooling water (first medium), the inverter cooling water (second medium), the ATF (third medium), and the engine 11 are distributed vertically but, at the start-up (time 0), these four are at substantially the same temperature.

The temperature of the engine cooling water is the temperature of the water temperature meter (T i) 14.

[0041]

Note that the solid line in each graph plots the individual temperature changes in the present embodiment, and the broken line plots the individual temperature changes in the case where the first heat exchanger 1 is not provided (which is a state where pipes of the circuit are directly coupled at the section of the heat exchanger.

The second heat exchanger 2 is provided) as a reference.

[0042]

(1) EV Driving Mode

FIG. 2 is a block diagram that illustrates a state where the operation takes place in the EV driving mode in the vehicle heat exchange system in accordance with the present embodiment.

In the EV driving mode, the engine 11 is controlled to be stopped by the ECU (electronic control unit) 40. Especially at the time of the start-up, the engine 11 and the engine cooling water are in a very cold state.

[0043] The ECU 40 performs switching of the water channel switch valve 16 such that the second path B is selected if the temperature of the engine cooling water is not in a predetermined high-temperature state, and the first path A is selected if the temperature of the engine cooling water is in the predetermined high-temperature state. Accordingly, at the time of the start-up, with regard to the water channel switch valve 16, the second path B is selected.

[0044]

First, in the EV driving mode at the time of the start-up, the driving motor 36 and the inverter 21 operate in response to the start-up, and the ATF and the inverter cooling water which cool the driving motor 36 and the inverter 21 experience rise in their temperatures. Also, the decelerator 31 rotates in response to the driving of the vehicle, and the ATF used for the purpose of lubrication is also warmed by the frictional heat of this decelerator 31. At this point, in the inverter cooling circuit 20, the inverter cooling water is heated as a result of the inverter cooling water having cooled the inverter 21, and is further subjected to heat exchange with the ATF by the second heat exchanger 2 and thus heated. In addition, the inverter cooling water that has been heated to a certain extent is cooled by the inverter radiator 23 and then supplied again for cooling of the inverter 21. As a result of this, as illustrated in FIG. 4 (EV driving mode 1), the inverter cooling water exhibits a relatively rapid temperature rise immediately after the start-up, but an equilibrium is soon established between the heating by the cooling of the inverter 21 and the ATF and the cooling by the inverter radiator 23, and saturation will be reached.

[0045]

Also, in the ATF cooling circuit 30, the ATF that has been heated by the driving motor 36, etc. is pumped from the drive unit 39, subjected to heat exchange with the engine cooling water by the first heat exchanger 1, further subjected to heat exchange with the inverter cooling water by the second heat exchanger 2, and cooled by these two heat exchanges, and then the ATF flows back to the drive unit 39. However, the heating by the driving motor 36 is predominant and, as illustrated in FIG. 4 (EV driving mode), the ATF exhibits relatively rapid temperature rise and reaches saturation on the way.

[0046]

Meanwhile, in the engine cooling circuit 10, the engine cooling water is subjected to the heat exchange with the ATF at the first heat exchanger 1, and provided in a warmed state for warm-up of the engine 11. In addition, since the engine cooling water that has cooled the engine 11 passes through the path B that has been selected by the water channel switch valve 16, the engine cooling water is supplied again to the first heat exchanger 1 without being cooled by the engine radiator 13. Hence, as illustrated in FIG. 4 (EV driving mode), the engine cooling water and the engine 11 exhibit gradual temperature rise.

[0047]

As has been described in the foregoing, in a state, immediately after the start up, where the engine 11 is stopped and driving only relies on the driving motor 36, the temperature of the engine cooling water used in cooling of the engine 11 is low, so that switching of the water channel switch valve 16 is made by the ECU 40 such that it selects the second path B. By virtue of this, the engine cooling water, without being cooled by the engine radiator 13, is subjected to the heat exchange at first heat exchanger 1 with the ATF used in cooling of the driving motor 36, which can promote the warm-up of the engine 11. In this manner, the exhaust heat produced from the driving motor 36 can be effectively utilized.

[0048]

(2) HV Driving Mode

FIG. 3 is a block diagram that illustrates a state where the operation takes place in the HV driving mode in the vehicle heat exchange system in accordance with the present embodiment.

In general, after having run to a certain extent in the EV driving mode, a hybrid vehicle shifts to the HV driving mode when a condition is satisfied such as a condition that the driving speed is faster than a predetermined value or a condition that the remaining capacity of a battery is insufficient. The ECU 40 receives the water temperature of the water temperature meter 14 and determines that the engine cooling water is in the predetermined high-temperature state.

[0049]

When the command of the ECU 40 causes the shift to the HV driving mode, then the engine 11 operates. On the other hand, when the temperature of the engine cooling water is in the predetermined high-temperature state, then the ECU 40 switches the water channel switch valve 16 as illustrated in FIG. 3 such that the first path A is selected. Note that, in the HV driving mode, the power generation motor 35 also starts to operate.

[0050]

At this point, in the inverter cooling circuit 20, in a similar manner as in the case of the EV driving mode, the inverter cooling water is warmed as a result of the inverter cooling water having cooled the inverter 21, and is further subjected to heat exchange with the ATF by the second heat exchanger 2, and receives heat from the higher- temperature ATF and is thus heated. The ATF has the function of cooling not only the driving motor 36 but also the power generation motor 35 that has begun to operate inside the drive unit 39. In addition, the inverter cooling water that has entered the high-temperature state is cooled by the inverter radiator 23 and is then supplied again for cooling of the inverter 21. As a result of this, with regard to the inverter cooling water, an equilibrium is established between the heating by the inverter 21 and the second heat exchanger 2 and the cooling by the inverter radiator 23, and as illustrated in FIG. 4 (HV driving mode), the temperature is kept constant.

[0051]

Also, in the ATF cooling circuit 30, the ATF that has been heated by the driving motor 36, the decelerator 31, and the power generation motor 35 is pumped from the drive unit 39 and, is subjected to heat exchange with the engine cooling water by the first heat exchanger 1, further subjected to heat exchange with the inverter cooling water by the second heat exchanger 2, and cooled by these two heat exchanges, and then the ATF flows back to the drive unit 39. As will be described later, since cooling by the second heat exchanger 2 with the inverter cooling water that has been cooled strongly by the inverter radiator 23 is performed in addition to the cooling by the first heat exchanger 1 with the engine cooling water that has been cooled strongly by the engine radiator 13, an equilibrium is established between the heating by the driving motor 36, the decelerator 31, and the power generation motor 35 and the cooling by the two heat exchangers, and as illustrated in FIG. 4 (HV driving mode), the ATF is maintained at a constant temperature.

[0052]

Meanwhile, the engine 11 starts the operation and thereby produces high heat and, as illustrated in FIG. 4 (HV driving mode), exhibits a rapid temperature rise.

Against this, the engine cooling water is cooled strongly by the engine radiator 13.

In the engine cooling circuit 10, the engine cooling water, after having been cooled strongly by the engine radiator 13, is supplied to the engine 11 in a state where the engine cooling water is subjected to the heat exchange with the ATF at the first heat exchanger 1 and is thus warmed.

[0053]

Even when heating through heat exchange with the ATF at the first heat exchanger 1 is done in addition to heating as a result of cooling of the engine 11 that emits high heat, strong cooling is performed by the engine radiator 13, so that an equilibrium is established between the cooling thereby and the heating by all the two. As a result of this, as illustrated in FIG. 4 (HV driving mode), with regard to the engine cooling water, the temperature is kept constant. Also, with regard to the engine 11, the cooling with the engine cooling water causes the temperature rise to peak, and the temperature on the way is kept constant.

[0054]

As has been described in the foregoing, the heat exchange between the engine cooling water and the ATF is performed by the first heat exchanger 1, in addition to which the heat exchange between the inverter cooling water cooled by the inverter radiator 23 and then having cooled the inverter 21 and the ATF is performed by the second heat exchanger 2, by virtue of which the cooling of the ATF that has been heated by the driving motor 36, the power generation motor 35, etc. is performed. In this manner, the heat exchange of the ATF can be performed in a distributed manner by the first heat exchanger 1 and the second heat exchanger 2, and the load on the inverter radiator 23 can be reduced. Accordingly, compared to cooling both the inverter 21 and the ATF with the inverter cooling water alone, reduction in the size of the inverter radiator 23 can be achieved.

[0055]

Also, by virtue of the fact that the engine cooling water is subjected to the heat exchange with the ATF without involvement of the engine radiator 13 when the engine 11 is stopped, the engine 11 can be warmed up efficiently and, on the other hand, when the HV driving mode is entered, the engine 11 is operating, and the engine cooling water is in the predetermined high-temperature state, then the engine cooling water is supplied to the engine radiator 13 and thereby efficiently cooled.

[0056]

(3) EV Driving Mode 2 (after the HV driving mode)

In general, when the hybrid vehicle decelerates in the HV driving mode and the remaining capacity of the battery is sufficient, then the shift to the EV driving mode is made by the determination of the ECU. This also applies to the present embodiment.

When the command of the ECU 40 causes the shift from the HV driving mode to the EV driving mode, then the engine 11 stops. In response to this, the

temperatures of the engine and the engine cooling water decrease, and the engine cooling water is immediately taken out of the predetermined high-temperature state. IB

For this reason, the ECU 40 performs switching of the water channel switch valve 16 such that the second path B is selected. As a result of this, the vehicle heat exchange system of the present embodiment enters the state illustrated in FIG. 2 in a similar manner as discussed in the "(2) EV Driving Mode 2."

[0057]

In the inverter cooling circuit 20, in a similar manner as in the case of the HV driving mode, the inverter cooling water is warmed as a result of the inverter cooling water having cooled the inverter 21, and is further subjected to heat exchange with the ATF by the second heat exchanger 2, and the inverter cooling water receives heat from the higher-temperature ATF and is thus heated. In addition, the inverter cooling water that has entered the high-temperature state is cooled by the inverter radiator 23, and is then supplied for cooling of the inverter 21. As a result of this, with regard to the inverter cooling water, a heat balance similar to the saturating condition in the "(1) EV Driving Mode 1" is established, and, as illustrated in FIG. 4 (EV driving mode 2), the temperature is kept constant.

[0058]

Also, in the ATF cooling circuit 30, the ATF that has been heated by the driving motor 36, etc. is pumped from the drive unit 39 and, is subjected to heat exchange with the engine cooling water by the first heat exchanger 1, further subjected to heat exchange with the inverter cooling water by the second heat exchanger 2, cooled by these two heat exchanges, and then the ATF flows back to the drive unit 39. At this point, since the inverter cooling water is cooled strongly by the inverter radiator 23, an equilibrium is established between the heating by the driving motor 36 and the cooling by the two heat exchangers, and as illustrated in FIG. 4 (EV driving mode 2), the ATF is maintained at a constant temperature.

[0059]

Meanwhile, as a result of stoppage of the operation of the engine 11, new exhaust heat is not produced from the engine 11.

In the engine cooling circuit 10, the engine cooling water is subjected to heat exchange with the ATF in the first heat exchanger 1 without flowing through the engine radiator 13, and is supplied to the engine 11. At this point, since the engine cooling water is subjected to the heat exchange with the ATF and warmed, as illustrated in FIG. 4 (EV driving mode 2), the temperature will decrease gradually. In response to this, with regard to the engine 11 as well, the temperature will decrease gradually.

[0060]

(Second Embodiment)

FIG. 5 is a block diagram that schematically illustrates an overall configuration of a vehicle heat exchange system in accordance with a second embodiment illustrating an example of the present disclosure. The vehicle heat exchange system in accordance with the present embodiment has the same features as those of the vehicle heat exchange system in accordance with the first embodiment except for some additional components and paths. For this reason, components in FIG. 5 having the same configurations and the same functions as those of the vehicle heat exchange system in accordance with the first embodiment are assigned the same reference signs as those in FIG. 1 and explanations will not be repeated.

[0061] In the present embodiment, in the inverter cooling circuit 20, on the

downstream side of the electrically-powered inverter pump 22, a water temperature meter (T ) 24 that measures the water temperature of the circulating inverter cooling water and a water channel switch valve (second medium switch valve) 26 are arranged. Also, in the ATF cooling circuit BO, on the downstream side of the ATF pump 32, an oil temperature meter (T 3 ) 34 is arranged which measures the temperature of the ATF pumped up by the ATF pump 32.

[0062]

The water channel switch valve 26 is an electromagnetic directional switching valve, and is configured to be capable of selective switching between a third path C that supplies the inverter cooling water after having passed through the second heat exchanger 2 to the inverter 21 via the inverter radiator 23, and a fourth path D that supplies the inverter cooling water after having passed through the second heat exchanger 2 directly to the inverter 21 without involvement of the inverter radiator 23. It is ensured that the individual portions of the inverter cooling water that have passed through the paths merge into one flow before the inverter 21, and the inverter cooling circuit 20 is formed as a closed circuit.

[0063]

The vehicle heat exchange system of the present embodiment is controlled by the ECU (electronic control unit, control unit) 40.

With regard to the ECU 40, the results of detection of the engine cooling water temperature measured by the water temperature meter (T i) 14, the temperature of the inverter cooling water measured by the water temperature meter 24, and the temperature of the ATF measured by the oil temperature meter 34 are input via the input port. Also, the ECU 40 outputs control signals from the output port to the water channel switch valve 16 and the water channel switch valve 26 in accordance with the results of detection as well as the status of operation or stoppage of the engine 11 separately determined by the ECU 40 itself, controls this, and thereby manages the operation of the vehicle heat exchange system of the present embodiment.

[0064]

It should be noted that, with regard to the ECU 40, in addition to those that have been mentioned above, results of detection of the outside temperature, the traveling speed of the vehicle, etc. are input, and with these conditions taken into account, various devices and components such as the electrically-powered engine pump 12, electrically-powered inverter pump 22, ATF pump 32, etc. as well as the water channel switch valve 16 and the water channel switch valve 26 may be more precisely controlled.

[0065]

Next, a state of the operation of the vehicle heat exchange system in

accordance with the present embodiment will be described for each vehicle driving mode. In the following description, in the same manner as in the first embodiment, an example is described which is implemented with the series-parallel hybrid scheme having the HV driving mode. In addition, with regard to the temperature change of the media circulating in the individual circuits, in the same manner as in the first

embodiment, explanations will be given using a graph of FIG. 9. Note that FIG. 9 is the graph in the second embodiment which is created in the same manner as FIG. 5 used in the first embodiment. [0066]

The temperature of engine cooling water is the same as in the first

embodiment. Also, the temperature of the inverter cooling water is the result of measurement by the water temperature meter 24 and the temperature of the ATF is the result of measurement by the oil temperature meter 34.

[0067]

(1) EV Driving Mode

FIG. 6 is a block diagram that illustrates a state where the operation takes place in an EV driving mode in the vehicle heat exchange system in accordance with the present embodiment.

In the EV driving mode, the engine 11 is controlled by the ECU 40 such that the engine 11 is stopped. Especially at the time of the start-up, the engine 11 and the engine cooling water are in a very cold state. For this reason, at the time of the start up, by the ECU 40, with regard to the water channel switch valve 16, the second path B is selected.

Also, in the EV driving mode at the time of the start-up, the ECU 40 receives results of measurement of the water temperature meter 24 and the oil temperature meter 34, determines that the temperatures of the inverter cooling water and the ATF are not in their individual predetermined high-temperature states, and, as illustrated in FIG. 9, controls the system such that the fourth path D is selected for the water channel switch valve 26.

[0068]

First, in the EV driving mode at the time of the start-up, the driving motor 36 and the inverter 21 operate in response to the start-up, and the ATF and the inverter cooling water which cool the driving motor 36 and the inverter 21 experience rise in their temperatures. Also, the decelerator 31 rotates in response to the driving of the vehicle, and the ATF used for the purpose of lubrication is also warmed by the frictional heat of this decelerator 31. At this point, in the inverter cooling circuit 20, the inverter cooling water is heated as a result of the inverter cooling water having cooled the inverter 21, and is further subjected to heat exchange with the ATF by the second heat exchanger 2 and thus heated. In addition, the inverter cooling water that has been heated passes through the fourth path D that has been selected by the water channel switch valve 26 and is then directly supplied again for cooling of the inverter 21 without flowing through the inverter radiator 23. As a result of this, as illustrated in FIG. 9 (EV driving mode 1), the inverter cooling water immediately after the start-up exhibits a rapid temperature rise.

[0069]

Also, in the ATF cooling circuit 30, the ATF that has been heated by the driving motor 36, etc. is pumped from the drive unit 39 and, is subjected to heat exchange with the engine cooling water by the first heat exchanger 1, further subjected to heat exchange with the inverter cooling water by the second heat exchanger 2, and the ATF flows back to the drive unit 39. At this point, in the first heat exchanger 1, the ATF will have a higher temperature than that of the engine cooling water which is not heated at all but, in the second heat exchanger 2, the inverter cooling water whose temperature continues to rise as the inverter cooling water does not pass through the inverter radiator 23 will have a higher temperature than that of the ATF. Accordingly, the ATF is subjected to heat exchange with the engine cooling water by the first heat exchanger 1 and cooled, and then subjected to heat exchange with the inverter cooling water by the second heat exchanger 2 and heated. At this point, the heating by the heat exchange by the second heat exchanger 2 is predominant, and, as illustrated in FIG. 9 (EV driving mode 1), the ATF exhibits a rapid temperature rise.

[0070]

Meanwhile, in the engine cooling circuit 10, the engine cooling water is subjected to the heat exchange with the ATF at the first heat exchanger 1, and provided in a warmed state for warm-up of the engine 11. In addition, since the engine cooling water after the engine 11 has been warmed up passes through the path B that has been selected by the water channel switch valve 16, the engine cooling water is supplied again to the first heat exchanger 1 without being cooled by the engine radiator IB. Hence, as illustrated in FIG. 9 (EV driving mode 1), the engine cooling water and the engine 11 exhibit gradual temperature rise.

[0071]

As has been described in the foregoing, in a state, immediately after the start up, where the engine 11 is stopped and driving only relies on the driving motor 36, the temperature of the engine cooling water used in cooling of the engine 11 is low, so that switching of the water channel switch valve 16 is made by the ECU 40 such that the second path B is selected. By virtue of this, the engine cooling water is not cooled by the engine radiator 13, the heat exchange with the ATF used in cooling of the driving motor 36 is performed by the first heat exchanger 1, which can promote the warm-up of the engine 11. In this manner, the heat of the ATF as a result of the exhaust heat produced from the driving motor 36, etc. can be effectively utilized.

[0072]

Also, in the state immediately after the start-up, the drive unit 39 such as the driving motor 36 and the decelerator 31 is not sufficiently warmed. However, in the EV driving mode 1, the inverter cooling water that has been directly supplied to the inverter 21 and warmed without involvement of the inverter radiator 23 experiences rapid temperature rise and heat exchange is performed between the inverter cooling water that has experienced the temperature rise and the ATF by the second heat exchanger 2. By doing this, the ATF temperature rise is promoted, which can contribute to friction reduction of the drive unit 39 such as the driving motor 36 and the decelerator 31.

[0073]

(2) EV Driving Mode 2-1 (before the HV driving mode)

FIG. 7 is a block diagram that illustrates a state where the operation takes place in the EV driving mode when the temperature of the inverter cooling water has risen in the vehicle heat exchange system in accordance with the present embodiment.

In the EV driving mode, the ECU 40 receives results of measurement of the water temperature meter 24 and the oil temperature meter 34 and controls the system, in the case where the temperatures of the inverter cooling water and the ATF are in the predetermined high-temperature state, as illustrated in FIG. 7, such that, with regard to the water channel switch valve 26, the third path C is selected. This is referred to as the EV driving mode 2.

[0074]

At this point, in the inverter cooling circuit 20, in a similar manner as in the case of the EV driving mode 1, the inverter cooling water is warmed as a result of the inverter cooling water having cooled the inverter 21, and is further subjected to heat exchange with the ATF by the second heat exchanger 2, receives heat from the higher- temperature ATF and is thus heated. In addition, the inverter cooling water that has entered the predetermined high-temperature state passes through the third path C, cooled by the inverter radiator 23, and is then supplied for cooling of the inverter 21.

As a result of this, as illustrated in FIG. 9 (EV driving mode 2-1), the inverter cooling water will exhibit a relatively rapid temperature drop and saturation will be reached when the temperature drops to a certain extent.

[0075]

Also, in the ATF cooling circuit 30, the ATF that has been heated by the driving motor 36, etc. is pumped from the drive unit 39 and, is subjected to heat exchange with the engine cooling water by the first heat exchanger 1, further subjected to heat exchange with the inverter cooling water by the second heat exchanger 2, cooled by these two heat exchanges, and then flows back to the drive unit 39. At this point, since the inverter cooling water is cooled strongly by the inverter radiator 23, an equilibrium is established between the heating by the driving motor 36, etc. and the cooling by the two heat exchangers (the former is slightly more dominant) and, as illustrated in FIG. 9 (EV driving mode 2-1), the temperature rise of the ATF will peak, and the temperature rise will be slight.

[0076]

Meanwhile, in the engine cooling circuit 10, the engine cooling water is supplied for warming up the engine 11 in a state where the engine cooling water is subjected to the heat exchange with the ATF at the first heat exchanger 1 and thus warmed. Since the influence of the heat exchange with the ATF at the first heat exchanger 1 is more significant, slowdown of the temperature rise of the engine cooling water does not become so large. In other words, as illustrated in FIG. 5 (EV driving mode 2), the engine cooling water and the engine 11 will exhibit a gradual temperature rise though the temperature rise will be slightly slowed down as compared with the case of the EV driving mode 1.

[0077]

With regard to the determination by the ECU 40 that the temperatures of the inverter cooling water and the ATF are in the predetermined high-temperature state, for example, a temperature serving as a predetermined threshold may be specified in advance and the "high-temperature state" may be determined if the specified temperature is exceeded, and it may be determined that "the high-temperature state is not entered" if it is not exceeded, but the determination is not limited to this.

[0078]

For example, a mode may be contemplated in which the temperature serving as the threshold is not defined as one single value, where the temperature, which is determined as the specified temperature as described above and which is the basis for determining that the "high-temperature state" is entered when it is exceeded, and determining that the temperature has dropped and accordingly the "high-temperature state is not entered," is separately defined as a temperature lower than the defined specified temperature (a hysteresis state is specified). Also, the ECU 40 may receive various pieces of information other than the temperatures of the inverter cooling water and the ATF, for example, the pieces of information such as the water temperature of the engine cooling water, the outside temperature, and the traveling speed of the vehicle, and the determination of the "high-temperature state" or determination that the "high-temperature state is not entered" may be performed comprehensively with these pieces of information taken into account or in accordance with predetermined function calculation.

[0079]

The "high-temperature state" in the inverter cooling water and the ATF is an indicator determined in each of them. For example, it is desirable that, in the inverter cooling water, the state should be defined as a state where the cooling of the inverter radiator is desired.

[0080]

Note that, when the "temperature of the second medium" is mentioned in the context of the present disclosure, this refers, when applied to the present embodiment, to the temperature of the inverter cooling water whose portions have merged into one flow before flowing into the inverter 21 after the path branched into the portions for the first heat exchanger and the inverter radiator by the water channel switch valve 26.

[0081]

Also, when the "temperature of the third medium" is mentioned in the context of the present disclosure, this refers, when applied to the present embodiment, to the temperature of the ATF that is pumped out from the drive unit 39 by the ATF pump 32. It should be noted, however, that as in the present embodiment, it does not

necessarily follow that the temperature of the ATF measured immediately after the ATF has been pumped out by the ATF pump 32 is used as the criterion, but in the context of the present embodiment, the temperature measured at any location in an interval before the ATF is supplied to the first heat exchanger 1 from the tank of the drive unit 39 may be used as the criterion.

[0082]

As has been described in the foregoing, the heat exchange between the engine cooling water and the ATF is performed by the first heat exchanger 1, in addition to which the heat exchange between the inverter cooling water cooled by the inverter radiator 23 and then having cooled the inverter 21 and the ATF is performed by the second heat exchanger 2, by virtue of which cooling of the ATF that has been heated by the driving motor 36, etc. is performed. In this manner, the heat exchange of the ATF can be performed in a distributed manner by the first heat exchanger 1 and the second heat exchanger 2, and the load on the inverter radiator 23 can be reduced. Accordingly, compared to cooling both the inverter 21 and the ATF with the inverter cooling water alone, reduction in the size of the inverter radiator 23 can be achieved.

[0083]

Also, since the configuration is such that the ATF passes through the second heat exchanger 2 after having flowed through the first heat exchanger 1, the

temperature of the ATF supplied to the second heat exchanger 2 can be lowered in advance to some extent, by virtue of which the rise in the temperature of the inverter cooling water can be suppressed and reduction in the size of the inverter radiator 23 can be achieved.

[0084]

(3) HV Driving Mode FIG. 8 is a block diagram that illustrates a state where the operation takes place in the HV driving mode in the vehicle heat exchange system in accordance with the present embodiment.

In general, switching is made to the HV driving mode when the driving speed is equal to or larger than a predetermined value and/or the remaining capacity of the battery is insufficient. The ECU 40 receives the water temperature of the water temperature meter 14 and determines that the engine cooling water has entered the predetermined high-temperature state.

[0085]

When the command of the ECU 40 causes the shift to the HV driving mode, then the engine 11 will operate. On the other hand, when the temperature of the engine cooling water is in the predetermined high-temperature state, then the ECU 40 performs, as illustrated in FIG. 8, switching of the water channel switch valve 16 such that the first path A is selected. Note that, in the HV driving mode, the power generation motor 35 will also start the operation.

[0086]

At this point, in the inverter cooling circuit 20, in a similar manner as in the case of the EV driving mode 2, the inverter cooling water is warmed as a result of the inverter cooling water having cooled the inverter 21, and is further subjected to heat exchange with the ATF by the second heat exchanger 2, and the inverter cooling water receives heat from the higher-temperature ATF and is thus heated. The ATF has the function of cooling not only the driving motor 36 but also the power generation motor 35 that has begun to operate inside the drive unit 39. In addition, the inverter cooling water that has entered the high-temperature state is cooled by the inverter radiator 23 and is then supplied again for cooling of the inverter 21. As a result of this, with regard to the inverter cooling water, an equilibrium is established between the heating by the inverter 21 and the second heat exchanger 2 and the cooling by the inverter radiator 23 and, as illustrated in FIG. 9 (HV driving mode), the temperature is kept constant.

[0087]

Also, in the ATF cooling circuit 30, the ATF that has been heated by the driving motor 36, the decelerator 31, and the power generation motor 35 is pumped from the drive unit 39, subjected to heat exchange with the engine cooling water by the first heat exchanger 1, further subjected to heat exchange with the inverter cooling water by the second heat exchanger 2, and cooled by these two heat exchanges, and then the ATF flows back to the drive unit 39. As will be described later, since cooling by the second heat exchanger 2 with the inverter cooling water that has been cooled strongly by the inverter radiator 23 is performed in addition to the cooling by the first heat exchanger 1 with the engine cooling water that has been cooled strongly by the engine radiator 13, an equilibrium is established between heating by the driving motor 36, the decelerator 31, and the power generation motor 35 and cooling by the two heat exchangers and, as illustrated in FIG. 9 (HV driving mode), the ATF is maintained at a constant temperature.

[0088]

Meanwhile, the engine 11 starts the operation and thereby produces high heat, and as illustrated in FIG. 9 (HV driving mode), exhibits a rapid temperature rise.

Against this, the engine cooling water is cooled strongly by the engine radiator 13. In the engine cooling circuit 10, the engine cooling water, after having been cooled strongly by the engine radiator IB, is supplied to the engine 11 in a state where it is subjected to the heat exchange with the ATF at the first heat exchanger 1 and is thus warmed.

[0089]

Even when heating through heat exchange with the ATF at the first heat exchanger 1 is done in addition to heating as a result of cooling of the engine 11 that emits high heat, strong cooling is performed by the engine radiator 13, so that an equilibrium is established between the cooling thereby and the heating by all the two. As a result of this, as illustrated in FIG. 9 (HV driving mode), with regard to the engine cooling water, the temperature is kept constant. Also, with regard to the engine 11, the cooling with the engine cooling water will cause the temperature rise to peak, and the temperature on the way is kept constant.

[0090]

As has been described in the foregoing, the heat exchange between the engine cooling water and the ATF is performed by the first heat exchanger 1, in addition to which the heat exchange between the inverter cooling water cooled by the inverter radiator 23 and then having cooled the inverter 21 and the ATF is performed by the second heat exchanger 2, by virtue of which the cooling of the ATF that has been heated by the driving motor 36, the power generation motor 35, etc. is performed. In this manner, the heat exchange of the ATF can be performed in a distributed manner by the first heat exchanger 1 and the second heat exchanger 2, and the load on the inverter radiator 23 can be reduced. Accordingly, compared to cooling both the inverter 21 and the ATF with the inverter cooling water alone, reduction in the size of the inverter radiator 23 can be achieved.

[0091]

Also, by virtue of the fact that, when the engine 11 is stopped, the engine cooling water is subjected to the heat exchange with the ATF without involvement of the engine radiator 13, the engine 11 can be warmed up efficiently and, on the other hand, when the HV driving mode is entered, the engine 11 is operating, and the engine cooling water is in the predetermined high-temperature state, then it is supplied to the engine radiator 13 and thereby efficiently cooled.

[0092]

(4) EV Driving Mode 2-2 (after the HV driving mode)

When the command of the ECU 40 causes the shift from the HV driving mode to the EV driving mode, then the engine 11 stops. In response to this, the

temperatures of the engine and the engine cooling water decrease, and the engine cooling water is immediately taken out of the predetermined high-temperature state. For this reason, the ECU 40 performs switching of the water channel switch valve 16 such that the second path B is selected. As a result of this, the vehicle heat exchange system of the present embodiment enters the state illustrated in FIG. 7 in a similar manner as discussed in the "(2) EV Driving Mode 2-1."

[0093]

In the inverter cooling circuit 20, in a similar manner as in the case of the HV driving mode, the inverter cooling water is warmed as a result of the inverter cooling water having cooled the inverter 21, and is further subjected to heat exchange with the ATF by the second heat exchanger 2, receives heat from the higher-temperature ATF and is thus heated. In addition, the inverter cooling water that has entered the high-temperature state is cooled by the inverter radiator 23, and is then supplied for cooling of the inverter 21. As a result of this, the inverter cooling water will have a heat balance similar to the saturating condition at and after the "(2) EV Driving Mode 2-1" and, as illustrated in FIG. 9 (EV driving mode 2-2), the temperature is kept constant.

[0094]

Also, in the ATF cooling circuit 30, the ATF that has been heated by the driving motor 36, etc. is pumped from the drive unit 39 and, is subjected to heat exchange with the engine cooling water by the first heat exchanger 1, further subjected to heat exchange with the inverter cooling water by the second heat exchanger 2, and cooled by these two heat exchanges, and then the ATF flows back to the drive unit 39. At this point, since the inverter cooling water is cooled strongly by the inverter radiator 23, an equilibrium is established between the heating by the driving motor 36 and the cooling by the two heat exchangers, and as illustrated in FIG. 9 (EV driving mode 2-2), the ATF is maintained at a constant temperature.

[0095]

Meanwhile, as a result of stoppage of the operation of the engine 11, new exhaust heat is not produced from the engine 11.

[0096]

In the engine cooling circuit 10, the engine cooling water is subjected to heat exchange with the ATF in the first heat exchanger 1 without flowing through the engine radiator 13, and is supplied to the engine 11. At this point, since the engine cooling water is subjected to the heat exchange with the ATF and thus warmed, as illustrated in FIG. 9 (EV driving mode 2-2), the temperature will gradually decrease. In response to this, with regard to the engine 11 as well, the temperature will decrease gradually.

[0097]

(Third Embodiment)

FIG. 10 is a block diagram that schematically illustrates an overall configuration of a vehicle heat exchange system in accordance with the third embodiment illustrating an example of the present disclosure. The vehicle heat exchange system in accordance with the present embodiment has the same features as those of the vehicle heat exchange system in accordance with the second embodiment except that it differs from the latter in the configuration of the heat exchanger in use. For this reason, components in FIG. 10 having the same configurations and the same functions as those of the vehicle heat exchange system in accordance with the second embodiment are assigned the same reference signs as those in FIG. 5 and explanations will not be repeated.

[0098]

In the present embodiment, in place of the first heat exchanger 1 and the second heat exchanger 2 in the second embodiment, a three-phase type heat exchanger 5 having the functions of these two heat exchangers is used. This heat exchanger 5 is a heat exchanger in accordance with an embodiment illustrating an example of the present disclosure. FIG. 11 illustrates a perspective view of the heat exchanger 5, FIG. 12 illustrates a bottom view of the heat exchanger 5, and FIG. 13 illustrates a schematic configuration diagram for explanation of the internal structure of the heat exchanger 5.

[0099]

The heat exchanger 5 includes and is configured by a plurality of partition walls 55 stacked and arranged upon one surface of a base 54 (a part of the partition walls), and on the uppermost portion of the heat exchanger 5, a top panel 56 (a part of the partition walls) is stacked and arranged. The heat exchanger 5 defines a substantially square shape when viewed in its plan view (i.e., "when it is viewed from the side of the top panel 56 in the direction of stacking of the plurality of partition walls 55;" The same applies hereinafter). The base 54, the plurality of partition walls 55, and the top panel 56 are arranged such that each of them forms a cavity between the adjacent pairs, where each of them defines a flow channel. In the present embodiment, as illustrated in FIG. 13, a flow channel having a total of thirteen layers is formed by twelve partition walls 55, the base 54, and the top panel 56. In the following description, explanations will be provided with the first layer, the second layer, ..., and the thirteenth layer denoted in this order from the side of the top panel 56 to the side of the base 54.

[0100]

In the heat exchanger 5, the second layer, the fourth layer, and the sixth layer are a first flow channel X in which the engine cooling water flows. Also, the eighth layer, the tenth layer, and the twelfth layer are a second flow channel Y in which the inverter cooling water flows. In addition, the remaining odd-numbered layers are a third flow channel Z in which the ATF flows. In other words, from the top panel (partition wall at one end) 56 to an intermediate partition wall 55m (midway partition wall), the first flow channel X and the third flow channel Z are alternately arranged in the direction of stacking (the up-and-down direction in FIG. 13) of the plurality of partition walls 55; and from the intermediate partition wall 55m to the base (partition wall at the other end) 54, the second flow channel Y and the third flow channel Z are alternately arranged in the aforementioned direction of stacking.

In addition, the first flow channel X, the second flow channel Y, and the third flow channel Z are isolated from each other.

[0101]

In the top panel 56, near the inner side of the two corners on the diagonal, an engine cooling water introduction pipe 511 and an engine cooling water discharge pipe 512 are mounted. The engine cooling water introduction pipe 511 and the engine cooling water discharge pipe 512 are each in communication with intermittent pipes 513, 514 formed by a cooling water passage hole provided in the partition walls 55 inside the heat exchanger 5, and extended so as to penetrate the top panel 56 and the partition walls 55 stacked on the upper side of the intermediate partition wall 55m (including the partition wall that is the second closest to the intermediate partition wall 55m but not including the partition wall that is closest to the intermediate partition wall 55m).

[0102]

These extended intermittent pipes 513, 514 are isolated from the first layer, the third layer, and the fifth layer constituting the third flow channel Z at the portions penetrating these layers. On the other hand, no pipe wall is present in the portions penetrating the second layer, the fourth layer, and the sixth layer constituting the first flow channel X, and the intermittent pipes 513, 514 are in the state of communication with the flow channel of these individual layers.

[0103]

Accordingly, when the engine cooling water is introduced via the engine cooling water introduction pipe 511, the engine cooling water flows through the intermittent pipe 513 to be split into portions flowing in the second layer, the fourth layer, and the sixth layer constituting the first flow channel X to flow in the flow channel of these individual layers, and the portions of the engine cooling water advance to the other side on the diagonal. In addition, the portions of the engine cooling water that have been distributed in the flow channel of the layers are put together at the intermittent pipe 514 and discharged from the engine cooling water discharge pipe 512 penetrating the top panel 56.

[0104]

In the base 54, on the inner side of the two corners on the diagonal (the locations overlapping with the mounting sections of the engine cooling water introduction pipe 511 and the engine cooling water discharge pipe 512 in the plan view), an inverter cooling water introduction port 521 and an inverter cooling water discharge port 522 are provided. The inverter cooling water introduction port 521 and the inverter cooling water discharge port 522 are each in communication with intermittent pipes 523, 524 formed by a cooling water passage hole provided in the partition wall 55 inside the heat exchanger 5, and the intermittent pipes 523, 524 are extended so as to penetrate the base 54 and the partition walls 55 stacked on the lower side of the intermediate partition wall 55m (including the partition wall closest to the intermediate partition wall 55m but not including the intermediate partition wall 55m as such).

[0105]

These intermittent pipes 523, 524 are isolated from the thirteenth layer, the eleventh layer, and the ninth layer constituting the third flow channel Z at the portions penetrating these layers. On the other hand, with regard to these intermittent pipes 523, 524, no pipe wall is present in the portions penetrating the twelfth layer, the tenth layer, and the eighth layer constituting the second flow channel Y, and the intermittent pipes 523, 524 are in the state of communication with the flow channel of these individual layers.

[0106]

Accordingly, when the inverter cooling water is introduced via the inverter cooling water introduction port 521, the inverter cooling water flows through the intermittent pipe 523 to be split into portions flowing in the twelfth layer, the tenth layer, and the eighth layer constituting the second flow channel Y to flow in the flow channel of these individual layers and the portions of the inverter cooling water advance to the other side on the diagonal. In addition, the portions of the inverter cooling water that have been distributed into the flow channel of these individual layers are put together at the intermittent pipe 524 and discharged from the inverter cooling water discharge port 522 provided in the base 54.

[0107]

In the top panel 56, further, near the inner side of one of the two corners other than the corners at which the engine cooling water introduction pipe 511 and the engine cooling water discharge pipe 512 are mounted, an ATF introduction pipe 531 is mounted. The ATF introduction pipe 531 forms an intermittent pipe 533 formed by an oil passage hole provided in the partition wall 55 inside the heat exchanger 5 and is extended so as to penetrate the top panel 56 and the partition walls 55 stacked on the upper side of the intermediate partition wall 55m (including the partition wall closest to the intermediate partition wall 55m but not including the intermediate partition wall 55m as such).

[0108]

This intermittent pipe 533 is isolated from the second layer, the fourth layer, and the sixth layer constituting the first flow channel X at the portions penetrating these layers. On the other hand, no pipe wall is present in the portions penetrating the first layer, the third layer, the fifth layer, and the seventh layer constituting the third flow channel Z, and the intermittent pipe 533 is in the state of communication with the flow channel of these individual layers.

[0109]

Also, in the base 54, further, at a location overlapping with the mounting section of the ATF introduction pipe 531 in the plan view, an ATF discharge port 532 is provided. The ATF discharge port 532 is in communication with an intermittent pipe 534 formed by the oil passage hole provided in the partition wall 55 inside the heat exchanger 5, and the intermittent pipe 534 is extended so as to penetrate the base 54 and the partition walls 55 stacked on the lower side of the intermediate partition wall 55m (including the partition wall closest to the intermediate partition wall 55m but not including the intermediate partition wall 55m as such).

[0110]

This intermittent pipe 534 is isolated from the twelfth layer, the tenth layer, and the eighth layer constituting the second flow channel Y at the portions penetrating these layers. On the other hand, no pipe wall is present in the portions penetrating the thirteenth layer, the eleventh layer, and the ninth layer constituting the third flow channel Z, and the intermittent pipe 534 placed in the state of communication with the flow channel of these individual layers.

[0111]

Inside the heat exchanger 5, when viewed in the plan view, near the inner side of the corners on the other side in the diagonal with respect to the corners at which the ATF introduction pipe 531 and the ATF discharge port 532 are provided (in FIG. 11, among the four corners of the top panel 56, the corner which is not connected to any one of them), an intermittent pipe 535 formed by the oil passage holes provided in all of the partition walls 55 except for the top panel 56 and the base 54 is formed.

[0112]

This intermittent pipe 535 is isolated from the second layer, the fourth layer, and the sixth layer constituting the first flow channel X; and the eighth layer, the tenth layer, and the twelfth layer constituting the second flow channel Y at the portions penetrating these layers. On the other hand, no pipe wall is present in the portions penetrating all of the layers constituting the third flow channel Z, and the intermittent pipe 535 is in the state of communication with the flow channel of these individual layers. In other words, the first layer, the third layer, the fifth layer, and the seventh layer adjacent to the first flow channel (hereinafter they may be generically referred to as "upper layer(s)") are in communication with the ninth layer, the eleventh layer, and the thirteenth layer adjacent to the second flow channel (hereinafter they may be generically referred to as "lower layer") and a state is entered where a continuous flow channel is formed.

[0113]

Accordingly, when the ATF is introduced via the ATF introduction pipe 531, the ATF is distributed into the first layer, the third layer, the fifth layer, and the seventh layer constituting the third flow channel Z so as to flow in the flow channel of these individual layers and advances to the other side on the diagonal. The portions of the ATF that have been distributed into the flow channel of these individual layers are put together at the intermittent pipe 535 so as to flow in the direction toward the base 54. The ATF that has passed through the intermediate partition wall 55m is split into portions flowing in the ninth layer, the eleventh layer, and the thirteenth layer constituting the third flow channel Z so as to flow in the flow channel of these individual layers and advance to the original diagonal side. In addition, the portions of the ATF that have been distributed into the follow channel of these individual layers are put together at the intermittent pipe 534 and discharged from the ATF discharge port 532 provided in the base 54.

[0114]

The heat exchanger 5 is mounted to the vehicle, for example, by fastening the threaded holes provided at the four corners of the base 54 to a wall surface of the drive unit 39. At this point, in the wall surface of the drive unit 39 brought into threaded engagement, openings of pipes are provided which are individually

connected to the inverter cooling water introduction port 521, the inverter cooling water discharge port 522, and the ATF discharge port 532.

[0115]

Specifically, the pipe from the inverter 21 is connected to the inverter cooling water introduction port 521; the pipe directed toward the electrically-powered inverter pump 22 is connected to the inverter cooling water discharge port 522; and the pipe directed to the drive unit 39 is connected to the ATF discharge port 532. The coupling sections of them are sealed by a sealing member to prevent leakage of liquid.

[0116]

Meanwhile, pipes are also individually connected to the individual pipes mounted to the top panel 56. Specifically, the pipe from the electrically-powered engine pump 12 is connected to the engine cooling water introduction pipe 511; the pipe directed to the engine 11 is connected to the engine cooling water discharge pipe 512; and the pipe from the ATF pump 32 is connected to the ATF introduction pipe 531. The coupling sections of these pipes are also provided with sealing so as to prevent leakage of liquid.

With the configuration described above, the heat exchanger 5 in accordance with the present embodiment described using FIGS. 11 to 13 is incorporated into the vehicle heat exchange system in accordance with the present embodiment illustrated in FIG. 10.

[0117]

In the vehicle heat exchange system in accordance with the present

embodiment, the heat exchanger 5 is configured to include the functions of both of the first heat exchanger 1 and the second heat exchanger 2 of the vehicle heat exchange system in accordance with the second embodiment. Specifically, the first layer to the seventh layer in the heat exchanger 5 have the functionality of the first heat exchanger 1 and the eighth layer to the thirteenth layer have the functionality of the second heat exchanger 2. Also, the intermittent pipe 535 has the functionality of the pipe constituting part of the ATF cooling circuit 30, provides communication between the upper layers and the lower layers inside the heat exchanger 5 and connects the first heat exchanger 1 to the second heat exchanger 2 in the vehicle heat exchange system in accordance with the second embodiment.

[0118]

The vehicle heat exchange system in accordance with the present embodiment basically has the same features as those of the second embodiment except that it differs from the second embodiment in the configuration of the heat exchanger and, with regard to the state where the system is actually operated, will basically have the same operation status. Accordingly, the explanations about the state of the operation and the explanations about the transition of the temperatures of the individual circulating media and the engine are replaced by those in the context of the second embodiment and they are not repeated in the present embodiment.

[0109]

According to the present embodiment, while maintaining the functions of the vehicle heat exchange system in accordance with the second embodiment, the first heat exchanger 1 and the second heat exchanger 2 can be integrated into one single unit and its size can be reduced, which in turn achieves a smaller installation space of the system. Also, it will be appreciated that it is also possible to obtain the operations and effects that have been described in the context of the second embodiment.

[0120]

The heat exchanger 5 in accordance with the present embodiment is illustrated as the one that has a square shape when viewed in the plan view, but the present disclosure is not limited to this shape and may include various shapes (including an irregular shape). For example, when the heat exchanger 5 has an elongated shape such as a rectangle and an ellipse, when viewed in the plan view, then the flow channel of the medium flowing in the inside can be extended to improve the heat exchange efficiency. In this case, it is preferable that the media between which heat exchange takes place flow in the opposite directions.

[0121]

In the present embodiment, the seventh layer adjacent to the intermediate partition wall 55m is defined as the layer adjacent to the sixth layer constituting the first flow channel X, and as the layer in which the ATF that has been introduced into the heat exchanger 5 flows first (upper layer), but this layer is also adjacent to the eighth layer constituting the second flow channel Y, and this layer may also be configured as a layer in which the ATF that has been passed through the upper layers flows first (lower layer). In this case, the partition wall 55 between the sixth layer and the seventh layer becomes the intermediate partition wall, the intermittent pipe 533 is terminated at the fifth layer without penetrating the sixth layer, and the intermittent pipe 534 penetrates the eighth layer and extends to the seventh layer, and a state of communication is provided.

[0122]

While the heat exchanger 5 in accordance with the present embodiment has a configuration that includes a total of thirteen layers, the number of layers is in no way limited. It suffices that the first flow channel and the third flow channel of the upper layers, and the second flow channel and the third flow channel of the lower layers each includes one or more layers (a total of four layers). Also, there may be difference in the number of layers between the upper layers and the lower layers. In the present embodiment, the first flow channel of the upper layers and the second flow channel and third flow channel of the lower layers each have three layers, and the third flow channel of the upper layers has four layers. Even when the number of layers is not IB, the significance of the intermediate partition wall, the upper layers, and the lower layers is as has been discussed in the foregoing.

[0123]

As has been described in the foregoing, whilst the vehicle heat exchange system of the present disclosure has been described with reference to preferred embodiments, the vehicle heat exchange system of the present disclosure is not limited to the features of the above embodiments.

For example, in the above-described embodiments, the examples have been presented in which the third medium is the ATF (automatic transmission fluid), but the present disclosure is not limited to this, and as long as it is a medium for use in cooling of motors such as a driving motor and a power generation motor, the present disclosure can be applied. In vehicles, for example, continuously variable transmission fluids (CVTFs) used in continuously variable transmission and other heat media can be utilized, in addition to which a medium dedicated to cooling of a driving motor and a power generation motor may also be utilized. Among them, automatic transmission fluids such as ATFs and CVTFs are oil-based fluids and excellent in their insulation property, in addition to which their fluid volumes are relatively abundant and the decelerator, the driving motor, and the power generation motor are arranged close to each other according to layouts, so that it is particularly preferable that ATFs and CVTFs are adopted as the third medium in the present disclosure.

[0124]

Also, the positions of arrangement of the first heat exchanger and the second heat exchanger in the individual circuits are not limited to the positions of the above- described embodiments. For example, the first heat exchanger 1 and the second heat exchanger 2 in the ATF cooling circuit 30 may have an inverted positional relationship with each other (i.e., the direction of circulation of the ATF is in the reverse direction) (in a case where the heat exchanger 5 is used, the entrance and the exit of the ATF may be inverted with respect to the third embodiment). Needless to say, as has been discussed in the foregoing, the features of the above-described embodiments are particularly preferable, according to which the ATF passes through the second heat exchanger 2 after having passed through the first heat exchanger 1.

[0125]

It should be noted that, in the present disclosure, the fact that "the first medium is in a predetermined high-temperature state" means the temperature to which the first medium of the engine cooling water, etc. should be cooled by the radiator so that the first medium does not have a higher temperature for reasons associated with the operation of the vehicle (for example, so as to ensure that the first medium is not overheated), etc. or means that the first medium has a temperature near this temperature.

[0126] In addition, those skilled in the art would be able to modify the heat exchanger and the vehicle heat exchange system of the present disclosure as appropriate in accordance with conventionally known knowledge. It will be appreciated that such modifications are still included in the category of the present disclosure as long as they have the features of the heat exchanger or the vehicle heat exchange system of the present disclosure.

(Reference Signs List)

[0127]

1: first heat exchanger

2: second heat exchanger

3: third heat exchanger

5: heat exchanger

10: engine cooling circuit (first medium cooling circuit)

11: engine (internal combustion engine)

12: electrically-powered engine pump

13: engine radiator (internal combustion engine radiator)

14: water temperature meter (T i)

16: water channel switch valve (first medium switch valve)

17: heater core

18: throttle body

20: inverter cooling circuit (second medium cooling circuit)

21: inverter

22: electrically-powered inverter pump

23: inverter radiator

24: water temperature meter (T )

26: water channel switch valve (second medium switch valve)

30: ATF cooling circuit (third medium cooling circuit)

31: decelerator

32: ATF pump

34: oil temperature meter (T 3 )

35: power generation motor (motor)

36: driving motor (motor)

39: drive unit

40: ECU(control unit)

54: base (partition wall at the other end)

55: partition wall

55m: intermediate partition wall (midway partition wall)

56: top panel (partition wall at the one end)

511: engine cooling water introduction pipe

512: engine cooling water discharge pipe

513,514: intermittent pipe

521: inverter cooling water introduction port

522: inverter cooling water discharge port

523,524: intermittent pipe

531: ATF introduction pipe

532: ATF discharge port

533,534,535: intermittent pipe A: first path

B: second path C: third path

D: fourth path

X: first flow channel Y: second flow channel Z: third flow channel