JP5465935B2 - Vehicle cooling system - Google Patents

Description

  The present invention relates to a vehicle cooling system including an exhaust heat recovery device that heats a heat transfer fluid for engine cooling with exhaust heat.

  Conventionally, as can be seen in Patent Documents 1 and 2, exhaust heat recovery devices are known that promote engine warm-up by heating engine coolant, which is a heat transfer fluid, with engine exhaust heat. The exhaust heat recovery device is provided in an engine cooling circuit that circulates engine cooling water, and is configured as a heat exchanger that exchanges heat between exhaust gas and engine cooling water. Further, Patent Document 2 describes that in a vehicle cooling system equipped with such an exhaust heat recovery device, the engine warm-up is further promoted by stopping the circulation of the cooling water inside the engine during the warm-up. ing.

  Conventionally, Patent Document 3 describes a vehicle cooling system including two independent cooling circuits for cooling an engine and for cooling a transaxle system. With such a cooling system, the circulation of the cooling water in the other cooling circuit can be stopped while continuing the circulation of the cooling water in one cooling circuit. Therefore, in such a cooling system, it is possible to stop the circulation of the cooling water in the cooling circuit for the engine and promote the engine warm-up while continuing the circulation of the cooling water in the cooling circuit for the transaxle.

JP 2008-185002 A JP 2008-255944 A JP 2007-216799 A

  It is conceivable to employ an exhaust heat recovery device as found in Patent Literatures 1 and 2 in a vehicle cooling system including two independent cooling circuits as found in Patent Literature 3. In such a case, the exhaust heat recovery mechanism is installed in a cooling circuit for the engine. Even in the vehicle cooling system configured as described above, the circulation of the cooling water in the engine cooling circuit is stopped during the warming up of the engine, so that the cooling water stays in the engine and promotes the warming up of the engine. Can be planned. However, in such a case, the following problems arise.

  That is, in such a vehicle cooling system, when the cooling water circulation of the engine cooling circuit is stopped, the cooling water circulation of the exhaust heat recovery device is also stopped. Then, the cooling water staying in the exhaust heat recovery device continues to be heated by the exhaust heat, and the water temperature may rise excessively, and the cooling water may boil in the exhaust heat recovery device.

  The present invention has been made in view of such a situation, and the problem to be solved is to circulate cooling water in an engine in a vehicle cooling system in which an exhaust heat recovery device is provided in an engine cooling circuit. Is to prevent the cooling water in the exhaust heat recovery device from excessively rising while promoting warm-up of the engine.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
The vehicle cooling system according to claim 1, wherein the heat transfer fluid for cooling the engine is circulated by the first pump, and the heat transfer fluid for cooling the transaxle system is the second pump. And a cooling circuit for the transaxle system that is circulated by the engine, and an exhaust heat recovery device that is provided in the engine cooling circuit and heats the heat transfer fluid with the exhaust heat. In order to solve the above problem, the vehicle cooling system according to claim 1 circulates a heat transfer fluid to the exhaust heat recovery device by the second pump while the engine is operating and the first pump is stopped. I try to let them.

In such a configuration, by stopping the first pump and stopping the circulation of the heat transfer fluid in the engine cooling circuit, the heat transfer fluid can be retained in the engine to promote the warm-up of the engine. In the exhaust heat recovery apparatus at this time, the heat transfer fluid is not circulated depending on the first pump, but the heat transfer fluid is circulated by the second pump installed in the transaxle cooling circuit. Therefore, the circulation of the heat transfer fluid in the exhaust heat recovery device is continued even while the circulation of the heat transfer fluid in the engine cooling circuit for promoting warm-up of the engine is stopped. Therefore, according to the above configuration, it is possible to prevent an excessive increase in the temperature of the heat transfer fluid in the exhaust heat recovery device while stopping the circulation of the heat transfer fluid in the engine and promoting the warm-up of the engine. become.

The vehicle cooling system according to claim 2, wherein the heat transfer fluid for cooling the engine is circulated by the first pump, and the heat transfer fluid for cooling the transaxle system is the second pump. And a cooling circuit for the transaxle system that is circulated by the engine, and an exhaust heat recovery device that is provided in the engine cooling circuit and heats the heat transfer fluid with exhaust heat. In order to solve the above-mentioned problem, the vehicle cooling system according to claim 2 includes a connection means for connecting the exhaust heat recovery device to the transaxle cooling circuit, the engine being operated, and the first pump And control means for controlling the connecting means so that the exhaust heat recovery device is connected to the transaxle cooling circuit during the stop.

In such a configuration, when the first pump is stopped, the circulation of the heat transfer fluid of the exhaust heat recovery device by the first pump is stopped. However, in the above configuration, when the first pump is stopped, the connecting means is controlled by the control means so as to connect the exhaust heat recovery device to the transaxle cooling circuit. As a result, the heat transfer fluid is circulated in the exhaust heat recovery device by the second pump provided in the transaxle cooling circuit. Therefore, in the above configuration, the circulation of the heat transfer fluid in the exhaust heat recovery device is continued even when the circulation of the heat transfer fluid in the engine cooling circuit for promoting warm-up of the engine is stopped. Therefore, according to the above configuration, it is possible to prevent an excessive increase in the temperature of the heat transfer fluid in the exhaust heat recovery device while stopping the circulation of the heat transfer fluid in the engine and promoting the warm-up of the engine. become.

  In a vehicle cooling system including two cooling circuits for the engine and the transaxle system, it is desirable to make the two cooling circuits independent in order to perform individual heat management after the engine warm-up is completed. Therefore, as described in claim 3, after the warm-up of the engine is completed, the connection between the exhaust heat recovery device and the transaxle system cooling circuit by the connecting means is released, and the engine cooling circuit and the transaxle system cooling are disconnected. The control means may be configured to be independent of the circuit.

  A heating device for heating a passenger compartment includes a heater core that exchanges heat between a heat transfer medium for cooling an engine and air blown into the passenger compartment. In order to effect heating early after the engine is started, it is necessary to start supplying the heated heat transfer medium to the heater core at an earlier stage. In this respect, in the vehicle cooling device according to claim 4, the heater core of the heating device for heating the vehicle interior is provided in the engine cooling circuit, and the heater core is used for the transaxle system simultaneously with the exhaust heat recovery device. The connecting means is configured to connect to the cooling circuit. Therefore, supply of the heat transfer medium heated by the exhaust heat recovery device to the heater core can be started from an early stage, and heating performance can be secured early.

  By the way, in recent years, a hybrid vehicle having two types of drive sources of an engine and a motor has been put into practical use. Many of these hybrid vehicles are provided with an inverter for driving the motor. Since the inverter generates heat during its operation, it is necessary to cool the inverter while the vehicle is running. Therefore, in many hybrid vehicle cooling systems, an inverter for driving a motor is connected to a cooling circuit for a transaxle system to cool the inverter.

  In such a vehicle cooling system, when the exhaust heat recovery device and the transaxle system cooling circuit are connected, the vehicle passes through the inverter and the exhaust heat recovery device and bypasses the transaxle system. Thus, the connecting means is configured so that the heat transfer fluid is circulated. In this case, since the transaxle system is excluded from the circulation circuit of the heat transfer fluid formed during engine warm-up, the thermal mass of the circulation circuit is reduced. Therefore, the temperature of the heat transfer fluid can be increased more quickly due to the heat generated by the exhaust heat recovery device and the inverter. For example, when the heater core of the heating device is included in the circulation circuit of the heat transfer fluid during engine warm-up, early heating performance can be ensured.

  In the vehicle cooling system of the present invention, the connecting means includes a bypass flow path for connecting the exhaust heat recovery device and the transaxle cooling circuit, and a bypass for the bypass heat recovery device. And a valve that selectively permits and prohibits the flow of the heat transfer fluid through the flow path.

1 is a block diagram schematically showing the overall configuration of a first embodiment of a vehicle cooling system according to the present invention. The block diagram which shows the circulation aspect of the cooling water after the engine warming-up in the same embodiment. The block diagram which shows the circulation aspect of the cooling water in the engine warming-up in the same embodiment. The flowchart which shows the process sequence of the cooling system control routine employ | adopted as the embodiment. The block diagram which shows typically the whole structure of 2nd Embodiment of the cooling system of the vehicle which concerns on this invention. The block diagram which shows typically the whole structure of 3rd Embodiment of the cooling system of the vehicle which concerns on this invention.

(First embodiment)
Hereinafter, a first embodiment of a vehicle cooling system according to the present invention will be described in detail with reference to FIGS. In the present embodiment, the cooling system according to the present invention is applied to a hybrid vehicle including two types of drive sources of an engine and a motor.

  FIG. 1 shows the overall configuration of a vehicle cooling system according to the present embodiment. As shown in the figure, this vehicle cooling system includes two cooling circuits, that is, an engine cooling circuit 10 and a transaxle system (T / A) cooling circuit 20.

  The engine cooling circuit 10 is provided with an engine water pump 11 as a first pump that circulates cooling water, which is a heat transfer fluid, in the cooling circuit. The engine cooling circuit 10 includes an engine water pump 11, an engine (E / G) 12, a heater core (HC) 13, an exhaust heat recovery device (EHR) 14, an engine 12 again, and an engine radiator 15. After passing, it is formed so as to return to the engine water pump 11 again. Here, the heater core 13 is a heat exchanger that heats the air blown into the vehicle interior by heat exchange with the cooling water. The exhaust heat recovery device 14 is a heat exchanger that heats the cooling water by exchanging heat with the exhaust of the engine 12, and the engine radiator 15 is a heat exchanger that cools the cooling water by exchanging heat with the outside air. It has become.

  On the other hand, the T / A cooling circuit 20 is provided with a T / A water pump 21 as a second pump for circulating cooling water through the cooling circuit. The T / A cooling circuit 20 includes, in order from the T / A water pump 21, a T / A radiator 22, a transaxle (T / A) 23 of a vehicle such as an ATF warmer or a differential, and an inverter (INV for driving a motor). ) After passing through 24, it is formed so as to return to the T / A water pump 21 again. Here, the T / A radiator 22 is a heat exchanger that cools the cooling water by heat exchange with the outside air.

  Further, in the vehicle cooling system of the present embodiment, the first and second bypass passages 30, 31 connecting the exhaust heat recovery device 14 and the T / A cooling circuit 20, and the bypass passages (30, 31) and an electromagnetically driven valve 32 that selectively permits and prohibits the flow of the cooling water through 31). In the present embodiment, the first bypass flow path 30 connects the upstream of the heater core 13 of the engine cooling circuit 10 and the downstream of the T / A water pump 21 of the T / A cooling circuit 20. Is formed. Further, the second bypass flow path 31 is formed so as to connect the downstream of the exhaust heat recovery device 14 of the engine cooling circuit 10 and the upstream of the transaxle 23 of the T / A cooling circuit 20. The electromagnetically driven valve 32 is installed at the connection between the first bypass flow path 30 and the engine cooling circuit 10. In the present embodiment, the first and second bypass passages 30 and 31 and the electromagnetically driven valve 32 constitute the connection means.

  Further, the vehicle cooling system according to the present embodiment includes an electronic control unit (ECU) 40 as a control means for controlling the two water pumps (11, 21) and the electromagnetically driven valve 32. The electronic control unit 40 temporarily stores a central processing unit (CPU) that performs arithmetic processing related to pump and valve control, a read-only memory (ROM) that stores control programs and data, CPU arithmetic results, etc. And a random access memory (RAM) for storing the data.

  In the vehicle cooling system of the present embodiment configured as described above, the engine cooling circuit 10 and the T / A cooling circuit 20 are basically independent cooling circuits. That is, the cooling water is normally circulated in the manner shown in FIG. 2, and the cooling waters flowing through both cooling circuits (10, 20) are not mixed with each other.

  On the other hand, in the vehicle cooling system of the present embodiment, the electronic control unit 40 stops the operation of the engine water pump 11 while the engine 12 is warmed up, and stops the circulation of the cooling water in the engine cooling circuit 10. By doing so, the cooling water staying inside the engine 12 is continuously heated so that the cooling water can be warmed up quickly, and thus the engine 12 can be warmed up early. In this case, when the engine water pump 11 is stopped, the circulation of the cooling water in the exhaust heat recovery device 14 is also stopped. As a result, the cooling water staying in the exhaust heat recovery device 14 continues to be heated by the exhaust heat, and the cooling water in the exhaust heat recovery device 14 may boil due to excessive temperature rise.

  Therefore, in the present embodiment, the cooling water boiled by continuing the circulation of the cooling water in the exhaust heat recovery device 14 by the T / A water pump 21 even when the engine water pump 11 for warming up the engine is stopped. Try to avoid. For this reason, in the present embodiment, the exhaust heat recovery device 14 can be connected to the T / A cooling circuit 20 by the first and second bypass flow paths 30 and 31, and electromagnetic waves are generated while the engine water pump 11 is stopped. The drive valve 32 is opened, and the exhaust heat recovery device 14 is connected to the T / A cooling circuit 20.

  That is, while the engine 12 is warming up, the electronic control unit 40 stops the engine water pump 11 to stop the cooling water circulation in the engine cooling circuit 10 and opens the electromagnetically driven valve 32 to open the exhaust heat recovery device 14. Is connected to the T / A cooling circuit 20. The flow of the cooling water in the cooling system at this time is as shown in FIG. That is, in this case, a circulation path of the cooling water passing through the T / A water pump 21, the heater core 13, the exhaust heat recovery device 14, the transaxle 23, and the inverter 24 is formed.

  FIG. 4 shows a flowchart of a cooling system control routine employed in the present embodiment. The processing of this routine is performed by the electronic control unit 40 when the engine 12 is started.

  When the processing of this routine is started, the electronic control unit 40 first checks in step S101 whether or not the engine 12 has been warmed up. Whether or not the engine 12 has been warmed up is determined based on the temperature of the cooling water in the engine cooling circuit 10. More specifically, if the temperature of the cooling water in the engine cooling circuit 10 is equal to or lower than a predetermined determination value, it is determined that the engine 12 has not been warmed up. Here, if the warm-up of the engine 12 has not yet been completed (S101: YES), the electronic control unit 40 proceeds to step S102, otherwise (S101: NO), the process proceeds to step S107.

  When the process proceeds to step S102, the electronic control unit 40 stops the engine water pump 11 in step S102 if the engine water pump 11 is not stopped. Further, in the subsequent step S103, the electronic control unit 40 opens the electromagnetically driven valve 32 and causes the first and second bypass flow paths 30, 31 to communicate with each other. As a result, a circulation path of the cooling water passing through the T / A water pump 21, the heater core 13, the exhaust heat recovery device 14, the transaxle 23, and the inverter 24 is formed as shown in FIG.

  Subsequently, in step S104, the electronic control unit 40 confirms whether or not the cooling water in the exhaust heat recovery device 14 is in a state where it may boil. This confirmation is performed based on the load of the engine 12 and the outside air temperature. Here, if the electronic control unit 40 is in a state where there is no possibility of boiling (S104: YES), the electronic control unit 40 waits as it is until there is a possibility of boiling. On the other hand, if there is a possibility of boiling, the electronic control unit 40 proceeds to the process of step S105.

  When the process proceeds to step S105, the electronic control unit 40 activates the electronic control unit 40 if the T / A water pump 21 is stopped in step S105, and proceeds to step S106. In subsequent step S106, the electronic control unit 40 waits until it is confirmed that the warm-up of the engine 12 is completed. The electronic control unit 40 at this time determines that the warm-up of the engine 12 has been completed if the temperature of the cooling water in the engine cooling circuit 10 is equal to or higher than a predetermined determination value. When it is confirmed that the engine 12 has been warmed up (S105: YES), the electronic control unit 40 proceeds to the process of step S107.

  When the process proceeds to step S107, the electronic control unit 40 operates the engine water pump 11 in step S107. Then, in the following step S108, the electronic control unit 40 closes the electromagnetically driven valve 32 to make both the cooling circuits (10, 20) independent from each other, and then ends the processing of this routine.

According to the vehicle cooling system of the present embodiment described above, the following effects can be obtained.
(1) The vehicle cooling system according to the present embodiment includes an engine cooling circuit 10 in which cooling water for cooling the engine 12 is circulated by the engine water pump 11, and T for cooling water for cooling the transaxle system. / A The cooling circuit 20 for T / A circulated by the water pump 21 is provided. The vehicle cooling system of the present embodiment also includes an exhaust heat recovery device 14 that is provided in the engine cooling circuit 10 and heats the cooling water with exhaust heat. In the vehicle cooling system of the present embodiment, the cooling water is circulated to the exhaust heat recovery device 14 by the T / A water pump 21 while the engine water pump 11 is stopped. Specifically, the vehicle cooling system of the present embodiment includes first and second bypass flow paths 30 and 31 and an electromagnetically driven valve for connecting the exhaust heat recovery device 14 to the T / A cooling circuit 20. 32. At the same time, an electronic control unit 40 is provided for controlling the electromagnetically driven valve 32 so that the exhaust heat recovery device 14 is connected to the T / A cooling circuit 20 while the engine water pump 11 is stopped. In the present embodiment, when the engine water pump 11 is stopped, the electromagnetically driven valve 32 is controlled by the electronic control unit 40 so as to connect the exhaust heat recovery device 14 to the T / A cooling circuit 20. As a result, cooling water is circulated in the exhaust heat recovery device 14 by the T / A water pump 21 provided in the T / A cooling circuit 20. Therefore, in the present embodiment, even when the circulation of the cooling water in the engine cooling circuit 10 for promoting warm-up of the engine 12 is stopped, the circulation of the cooling water in the exhaust heat recovery device 14 is continued. Become. Therefore, according to the present embodiment, it is possible to prevent an excessive increase in the cooling water in the exhaust heat recovery device while stopping the circulation of the cooling water in the engine 12 and promoting the warm-up of the engine 12. become.

  (2) In the vehicle cooling system in which the engine cooling circuit 10 and the T / A cooling circuit 20 are independent, the inverter 24 is the only heat source for the transaxle system at the time of cold start. It takes time to warm up. In that respect, in the vehicle cooling system of the present embodiment, the cooling water heated by the exhaust heat recovery device 14 and the inverter 24 is supplied to the transaxle 23 while the engine 12 is warmed up. For this reason, the transaxle 23 can be warmed up early.

  (3) In the vehicle cooling system of the present embodiment, the electronic control unit 40 closes the electromagnetically driven valve 32 and completes the exhaust heat recovery device 14 and the T / A cooling circuit 20 after the warm-up of the engine 12 is completed. By releasing the connection, the engine cooling circuit 10 and the T / A cooling circuit 20 are made independent. Therefore, after the warm-up of the engine 12 is completed, individual heat management can be performed by the engine cooling circuit 10 and the T / A cooling circuit 20, and more effective heat management can be performed. It becomes like this.

  (4) The heating device for heating the vehicle interior includes a heater core 13 that exchanges heat between the cooling water flowing through the engine cooling circuit 10 and the air blown into the vehicle interior. It is necessary to start the supply of the heated cooling water to the heater core 13 at an earlier stage in order to make the heating effective later. In this regard, in the present embodiment, the heater core 13 of the heating device for heating the passenger compartment is provided in the engine cooling circuit 10, and the heater core 13 is simultaneously with the exhaust heat recovery device 14 during the warm-up of the engine 12. Are also connected to the T / A cooling circuit 20. Therefore, the supply of the cooling water heated by the exhaust heat recovery device 14 to the heater core 13 can be started from an early stage, and the heating performance can be secured early.

(Second Embodiment)
Next, a second embodiment of the vehicle cooling system according to the present invention will be described with reference to FIG.

  In order to ensure the heating performance of the passenger compartment at an early stage, it is necessary to supply the cooling water heated from the early stage to the heater core 13 of the heating apparatus. In that respect, in the vehicle cooling system of the first embodiment, the cooling water heated by the exhaust heat recovery device 14 is supplied to the heater core 13 while the engine 12 is warmed up. The heating performance can be secured. In the present embodiment, a vehicle cooling system capable of more efficiently ensuring the heating performance during the cold start of the engine 12 is proposed.

  FIG. 5 shows the configuration of the vehicle cooling system of the present embodiment. In the figure, illustration of the configuration of the control system of the cooling system is omitted. Incidentally, the control system of the cooling system includes an electronic control unit 40 (see FIG. 1) that controls the engine water pump 11, the T / A water pump 21, and the electromagnetically driven valve 32.

  As shown in the figure, the vehicle cooling system of the present embodiment also includes an engine cooling circuit 10 and a T / A cooling circuit 20. The engine cooling circuit 10 is formed so as to pass through the engine water pump 11, the engine 12, the heater core 13, the exhaust heat recovery device 14, and the engine radiator 15. The T / A cooling circuit 20 is formed so as to pass through the T / A water pump 21, the inverter 24, the transaxle 23, and the T / A radiator 22.

  Also in the present embodiment, the first and second bypass flow paths 30a and 31 for connecting the exhaust heat recovery device 14 to the T / A cooling circuit 20 and the electromagnetic drive when the engine water pump 11 is stopped. A valve 32 is provided. However, in the present embodiment, the first bypass flow path 30 a is connected to the T / A cooling circuit 20 downstream of the inverter 24 and upstream of the transaxle 23.

  In the vehicle cooling system according to the present embodiment, when the exhaust heat recovery device 14 and the T / A cooling circuit 20 are connected, the inverter 24, the heater core 13 and the exhaust heat recovery device 14 pass through, while the transaxle 23 The cooling water is circulated by bypassing. That is, in the present embodiment, the transaxle 23 is excluded from the circulation path of the cooling water during the warm-up of the engine 12.

  In the vehicle cooling system according to the present embodiment, the heat mass of the circulation circuit of the cooling water formed during the warm-up of the engine 12 is reduced by the amount that the transaxle 23 is excluded. Therefore, the temperature of the cooling water is increased more quickly due to the heat generated by the exhaust heat recovery device 14 and the inverter 24, and the cooling water heated from an earlier stage is supplied to the heater core 13.

According to the vehicle control apparatus of the present embodiment described above, in addition to the effects described in (1) to (4) above, the following effects can be further achieved.
(5) In the present embodiment, when the exhaust heat recovery device 14 and the T / A cooling circuit 20 are connected, the inverter 24, the heater core 13 and the exhaust heat recovery device 14 are bypassed while bypassing the transaxle 23. The cooling water is circulated. Therefore, the thermal mass of the circulating circuit of the cooling water formed during the warm-up of the engine 12 can be reduced, and the temperature of the cooling water can be raised more quickly due to the heat generated by the exhaust heat recovery device 14 and the inverter 24. Therefore, the heating performance can be secured earlier.

(Third embodiment)
Next, a third embodiment of the vehicle cooling system according to the present invention will be described with reference to FIG. In each of the embodiments described above, the vehicle cooling system is configured such that the engine cooling circuit 10 and the T / A cooling circuit 20 each include a radiator. In the present embodiment, an embodiment of the present invention when both cooling circuits share a radiator will be described.

  FIG. 6 shows the configuration of the vehicle cooling system of the present embodiment. In the figure, illustration of the configuration of the control system of the cooling system is omitted. Incidentally, the control system of the cooling system includes an electronic control unit 40 (see FIG. 1) that controls the engine water pump 11, the T / A water pump 21, and the electromagnetically driven valve 32.

  In the vehicle cooling system of the present embodiment, the T / A cooling circuit is provided in the first flow path 20 a connected upstream of the engine water pump 11 of the engine cooling circuit 10 and the engine cooling circuit 10. And a second flow path 20b connected upstream of the radiator 15a. Then, a T / A cooling is provided by disposing a T / A water pump 21, an inverter 24, and a transaxle 23 between the upstream end of the first flow path 20a and the downstream end of the second flow path 20b. A circuit is formed.

  Furthermore, in the vehicle cooling system of the present embodiment, the first bypass flow path is connected so as to connect the upstream of the heater core 13 of the engine cooling circuit 10 and the second flow path 20b of the T / A cooling circuit. 30b is formed. A second bypass flow path 31b is formed so as to connect the exhaust heat recovery device 14 downstream of the engine cooling circuit 10 and the first flow path 20a of the T / A cooling circuit. The electromagnetically driven valve 32 is installed at a connection portion between the engine cooling circuit 10 and the first bypass flow path 30b.

  Even in this embodiment, when the engine water pump 11 is stopped, the electromagnetically driven valve 32 is opened, and the exhaust heat recovery device 14 is used for T / A via the first and second bypass flow paths 30b and 31b. By connecting to the cooling circuit, circulation of the cooling water in the exhaust heat recovery device 14 can be continued. Therefore, according to the present embodiment, it is possible to prevent the cooling water from excessively rising in the exhaust heat recovery device 14 while stopping the circulation of the cooling water in the engine 12 and promoting the warm-up of the engine 12. It becomes like this.

The above-described embodiments can be implemented with the following modifications.
In the above embodiment, the heater core 13 installed in the engine cooling circuit 10 is connected to the T / A cooling circuit 20 simultaneously with the exhaust heat recovery device 14 while the engine 12 is warming up. As a result, the cooling water heated by the exhaust heat recovery device 14 can be supplied to the heater core 13 while the engine 12 is warmed up, thereby enabling early use of heating. However, when it is not necessary to use heating before the engine 12 is warmed up, only the exhaust heat recovery device 14 may be connected to the T / A cooling circuit 20. Also in this case, since the cooling water circulation of the exhaust heat recovery device 14 can be continued while the engine water pump 11 is stopped, the circulation of the cooling water in the engine is stopped to promote the warm-up of the engine. In addition, it is possible to prevent an excessive increase in the cooling water in the exhaust heat recovery device.

  In the above embodiment, after the warm-up of the engine 12 is completed, the connection between the exhaust heat recovery device 14 and the T / A cooling circuit 20 by the electromagnetically driven valve 32 is released, and the engine cooling circuit 10 and the T / A The cooling circuit 20 for A was made independent. However, when it is not necessary to separately manage the heat of both cooling circuits, the connection between the exhaust heat recovery device 14 and the T / A cooling circuit 20 by the electromagnetically driven valve 32 is released even after the engine 12 is warmed up. You may make it operate these cooling circuits, without doing.

  -The connection aspect of the 1st and 2nd bypass flow paths 30 and 31 with respect to both the cooling circuits (10, 20) in the said embodiment may be changed suitably. Whatever the connection mode of the first and second bypass flow paths 30 and 31, the exhaust heat recovery device 14 is connected to the T / A cooling circuit 20 while the engine water pump 11 is stopped. If the cooling water is circulated to the exhaust heat recovery device 14 by the pump 21, the above problem can be solved.

  In the above embodiment, the exhaust heat recovery device 14 and the T / A cooling circuit 20 are connected by the electromagnetically driven valve 32. However, the connection is disconnected by other means such as a thermostat. You may make it contact.

In the above embodiment, the case where the cooling system of the present invention is applied to a hybrid vehicle including two types of drive sources of the engine 12 and the motor has been described, but the present invention is also applied to a vehicle other than the hybrid vehicle. be able to. In short, if the vehicle cooling system has the following configurations (a) to (c), the application of the present invention can stop the circulation of the cooling water in the engine and promote the warm-up of the engine. Further, it is possible to prevent an excessive increase in the cooling water in the exhaust heat recovery device.
(A) An engine cooling circuit in which a heat transfer fluid for cooling the engine is circulated by the first pump.
(B) A transaxle system cooling circuit in which a heat transfer fluid for cooling the transaxle system is circulated by the second pump.
(C) An exhaust heat recovery device that is provided in the engine cooling circuit and heats the heat transfer fluid with exhaust heat.

  DESCRIPTION OF SYMBOLS 10 ... Engine cooling circuit, 11 ... Engine water pump (1st pump), 12 ... Engine, 13 ... Heater core, 14 ... Exhaust heat recovery device, 15 ... Engine radiator, 15a ... Engine, T / A common radiator 20 ... T / A cooling circuit (transaxle system cooling circuit), 20a, 20b ... flow path (transaxle system cooling circuit), 21 ... T / A water pump (second pump), 22 ... T / Radiator for A, 23 ... transaxle, 24 ... inverter, 30, 30a, 30b ... first bypass flow path (connection means), 31, 31b ... second bypass flow path (connection means), 32 ... electromagnetically driven valve (Connection means), 40... Electronic control unit (control means).

Claims (6)

A cooling circuit for the engine in which a heat transfer fluid for cooling the engine is circulated by the first pump; a cooling circuit for the transaxle system in which a heat transfer fluid for cooling the transaxle system is circulated by the second pump; An exhaust heat recovery device that is provided in the engine cooling circuit and heats the heat transfer fluid with exhaust heat;
The vehicle cooling system, wherein the heat transfer fluid is circulated to the exhaust heat recovery device by the second pump while the engine is operating and the first pump is stopped. A cooling circuit for the engine in which a heat transfer fluid for cooling the engine is circulated by the first pump; a cooling circuit for the transaxle system in which a heat transfer fluid for cooling the transaxle system is circulated by the second pump; An exhaust heat recovery device that is provided in the engine cooling circuit and heats the heat transfer fluid with exhaust heat;
Connection means for connecting the exhaust heat recovery device to the transaxle cooling circuit;
Control means for controlling the connecting means to connect the exhaust heat recovery device to the transaxle cooling circuit during operation of the engine and when the first pump is stopped;
A vehicle cooling system comprising: The vehicle cooling system according to claim 2,
The control means releases the connection between the exhaust heat recovery device and the transaxle system cooling circuit by the connecting means after the warming-up of the engine is completed, and the engine cooling circuit and the transaxle system A vehicle cooling system characterized by being independent of a cooling circuit. The engine cooling circuit is provided with a heater core of a heating device for heating the vehicle interior, and the connecting means connects the heater core to the transaxle cooling circuit simultaneously with the exhaust heat recovery device. The vehicle cooling system according to claim 2 or 3, wherein the vehicle cooling system is configured as described above. An inverter for driving the motor is connected to the cooling circuit for the transaxle system,
The connecting means passes through the inverter and the exhaust heat recovery device when the exhaust heat recovery device and the transaxle cooling circuit are connected, and the heat transfer fluid is circulated around the transaxle system. The vehicle cooling system according to any one of claims 2 to 4, wherein the vehicle cooling system is configured as described above. The connection means includes a bypass passage that connects the exhaust heat recovery device and the transaxle cooling circuit, and a valve that selectively permits and prohibits the flow of the heat transfer fluid through the bypass passage; The vehicle cooling system according to any one of claims 2 to 5, wherein the vehicle cooling system is provided.

Images