JP2010264876A - Cooling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling device capable of efficiently preventing knocking attributable to a temperature rise in a combustion chamber of an internal combustion engine during normal travel or the like by using an excessive cooling capacity without impairing a cooling effect of the internal combustion engine. <P>SOLUTION: In the engine cooling device 40 which is applied to a hybrid vehicle 1 and provided with an intake air cooling unit 60 having an intake air cooling water passage 66 branched from an engine cooling water passage 54 of an engine cooling unit 50, an electric water pump 61 for circulating cooling water in the intake air cooling unit 60, a radiator outlet water temperature sensor 64 for detecting a radiator water temperature Tr, and an engine outlet water temperature sensor 65 for detecting an engine water temperature Te, a control unit 10 performs the drive control of the electric water pump 61 when the radiator water temperature Tr exceeds the radiator water temperature Trth, and stops the drive of the electric water pump 61 when the engine water temperature Te exceeds an engine water temperature Teth<SB>1</SB>. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a cooling device, and more particularly, to a cooling device for a hybrid vehicle for an internal combustion engine provided independently of a cooling device for electrical equipment.

  In general, in a cooling device for a hybrid vehicle, an engine cooling device that cools an engine and a motor cooling device that cools a motor or the like are provided independently, and are configured by different refrigerant circulation systems.

  Here, the cooling capacity of the engine cooling device described above is determined by the heat dissipation capacity of the radiator. In particular, the cooling capacity is sufficient to cool the engine even under the highest engine load conditions during climbing and high-speed driving. It is set in advance.

  Further, the engine of the hybrid vehicle as described above adopts a so-called Atkinson cycle or the like in which, for example, the expansion ratio is increased and the thermal efficiency is increased as compared with the actual compression ratio. During normal running, the heat generation due to the combustion of the air-fuel mixture in the combustion chamber and the friction in the cylinder is reduced. Therefore, in the engine cooling device applied to the hybrid vehicle equipped with the engine employing the above-described Atkinson cycle or the like, the engine thermal efficiency is enhanced. The frequency of use decreases. For this reason, in the above-described engine cooling apparatus, the cooling capacity of the cooling apparatus for cooling the engine is surplus compared to the above-described preset cooling capacity.

By the way, as shown in FIG. 14, the engine of the hybrid vehicle cooled by the engine cooling device described above has a particularly low engine speed as compared with an engine mounted on a general vehicle that does not employ a hybrid system. In addition, since the engine torque (engine load) is used in a high load region, fuel efficiency can be improved. In other words, the broken lines a and b shown in FIG. 14 shows an operation line of an engine mounted on a general vehicle not employing the hybrid system, the solid lines f ₁ ~f ₅ shows the fuel consumption contours, from f ₅ to f ₁ It shows that fuel economy improves as you head. A thick solid line c indicates an operating line of an engine mounted on a vehicle adopting the hybrid system. Accordingly, the engine of the hybrid vehicle has an operation line set around the f ₁ region having particularly good fuel efficiency, as shown by a thick solid line c shown in FIG. Can be achieved.

  On the other hand, since the engine of a hybrid vehicle is used in a high load region as described above, the temperature in the combustion chamber is high and there is a risk that knocking is likely to occur.

  On the other hand, even in a general vehicle engine that does not employ a hybrid system, a high compression ratio is employed to improve the thermal efficiency of the engine, or high supercharging is performed by a supercharging means to achieve high engine output. In some cases, particularly when the temperature of the cylinder head rises, the natural self-ignition temperature is likely to be reached. As a result, knocking may easily occur.

  Conventionally, in order to suppress the occurrence of knocking due to the temperature rise of the cylinder head as described above, it has a main pump and a sub pump, and the main pump uses the main cooling path to supply the refrigerant to the cooling jacket of the cylinder block. After the supply, the refrigerant is supplied to the cooling jacket of the cylinder head, and the auxiliary pump supplies the refrigerant to the peripheral portion of the intake port in the cooling jacket of the cylinder head through the auxiliary cooling path without passing through the cooling jacket of the cylinder block. There has been known an engine cooling apparatus configured as described above (for example, see Patent Document 1).

  In such a conventional engine cooling device described in Patent Document 1, knocking occurs by highly cooling the cylinder head so that the temperature of the cylinder head does not reach the natural self-ignition temperature that causes knocking. Is suppressed.

Japanese Patent Laid-Open No. 02-256820

  However, in an engine cooling device mounted on a general vehicle that does not employ the conventional hybrid system as described above, the cylinder head cooling is performed at a low temperature start or at a low temperature regardless of whether the cooling capacity is excessive. While the amount of refrigerant supplied to the jacket is zero or extremely small, the amount of refrigerant supplied to the cooling jacket of the cylinder head is increased when the thermal load on the cylinder head is high. For this reason, for example, even when the engine load is highest, such as during climbing or high-speed traveling, the amount of refrigerant supplied to the cooling jacket of the cylinder head is increased when the thermal load on the cylinder head is high. As a result, the amount of refrigerant supplied to the cooling jacket of the cylinder block that needs to be cooled most is reduced. As a result, there is a possibility that the cooling of the engine in the state where the engine load is most applied becomes insufficient.

  Moreover, in the cooling device for engines of a hybrid vehicle, the subject that the surplus cooling capacity at the time of the above-mentioned normal driving etc. was not utilized effectively occurred.

  The present invention has been made in order to solve the above-described conventional problems, and uses the surplus cooling capacity without impairing the cooling effect of the internal combustion engine. An object of the present invention is to provide a cooling device that can efficiently prevent the occurrence of knocking due to a temperature rise.

  In order to achieve the above object, a cooling device according to the present invention is (1) a cooling device that includes an internal combustion engine and a rotating electrical machine, and is applied to a hybrid vehicle that uses at least one of the internal combustion engine and the rotating electrical machine as a travel source. A heat exchanger that exchanges heat between the refrigerant and the outside air, and a first circulation passage that circulates the refrigerant discharged from the heat exchanger to cool the internal combustion engine. And a second circulation channel that branches from the first circulation channel and circulates the refrigerant discharged from the heat exchanger so as to cool the intake air supplied to the internal combustion engine. A second cooling unit formed; a refrigerant circulating means for forcibly circulating the refrigerant; and a temperature detecting unit configured to detect a temperature of the refrigerant discharged from the heat exchanger. 1 refrigerant temperature detecting means; Second refrigerant temperature detection means for detecting the temperature of the refrigerant after cooling the internal combustion engine, and the temperature of the refrigerant detected by the first refrigerant temperature detection means exceeds a predetermined first threshold value. The refrigerant circulating means is controlled to circulate the refrigerant when the temperature of the refrigerant detected by the second refrigerant temperature detecting means exceeds a second threshold value greater than the first threshold value. And a control means for controlling the refrigerant circulation means to stop the circulation of the refrigerant.

  With this configuration, when the temperature of the refrigerant detected by the first refrigerant temperature detection unit exceeds the first threshold, the control unit controls the refrigerant circulation unit to circulate the refrigerant. During normal travel in an urban area or the like after completion, the intake air sucked into the internal combustion engine can be cooled using the surplus cooling capacity of the cooling device. For this reason, during normal traveling, the temperature rise in the combustion chamber of the internal combustion engine can be suppressed by utilizing the excess cooling capacity, and the occurrence of knocking due to the temperature rise in the combustion chamber can be prevented. .

On the other hand, when the temperature of the refrigerant detected by the second refrigerant temperature detection means exceeds a second threshold value that is larger than the first threshold value, the control means controls the refrigerant circulation means to stop the circulation of the refrigerant. For example, in the case of uphill traveling where the load applied to the internal combustion engine increases compared to during normal traveling, the cooling of each cylinder of the internal combustion engine that is originally required may be performed with priority over the cooling of the intake air. it can.
As the first threshold, for example, the temperature of the refrigerant is set after the completion of warming-up of the internal combustion engine and when there is a possibility of knocking due to the temperature rise in the combustion chamber of the internal combustion engine. In addition, as the second threshold value, for example, the temperature of the refrigerant when it is necessary to cool each cylinder of the internal combustion engine in preference to the cooling of the intake air is set.

  The cooling device according to the present invention is the cooling device according to (1) above, (2) provided on the second circulation flow path, and a part of the exhaust discharged from the internal combustion engine is taken into the intake air of the internal combustion engine It is determined whether or not the exhaust gas recirculated by the EGR device that recirculates to the passage is cooled by the refrigerant that circulates in the second circulation flow path, and whether the exhaust gas recirculation by the EGR device has stopped. EGR stop determination means, and the control means circulates the refrigerant so as to circulate the refrigerant when the temperature of the refrigerant detected by the first refrigerant temperature detection means exceeds the first threshold value. The exhaust gas recirculation by the EGR device is stopped by the EGR stop determining means and the exhaust gas recirculation by the EGR device is stopped. When spent, configured to control the refrigerant circulation means so as to stop the circulation of the refrigerant.

  With this configuration, when the temperature of the refrigerant detected by the first refrigerant temperature detection unit exceeds a predetermined first threshold value, the control unit controls the refrigerant circulation unit to circulate the refrigerant. During normal driving in an urban area or the like after completion of engine warm-up, the exhaust gas recirculated by the EGR device can be cooled by using the surplus cooling capacity of the cooling device. In addition, the intake air including the exhaust gas recirculated that is taken into the internal combustion engine is further cooled by the second cooling unit. For this reason, during normal traveling, the temperature rise in the combustion chamber of the internal combustion engine can be suppressed by utilizing the excess cooling capacity, and the occurrence of knocking due to the temperature rise in the combustion chamber can be prevented. .

  On the other hand, after the EGR stop determination means determines that the recirculation of exhaust gas by the EGR device has stopped, the control means controls the refrigerant circulation means to stop the circulation of the refrigerant. In the case of uphill traveling that increases compared to traveling, the cooling of the internal combustion engine that is originally required can be performed with priority over the cooling of the intake air. In addition, since the circulation of the refrigerant in the second cooling unit is stopped when a predetermined time has elapsed after the exhaust gas recirculation by the EGR device is stopped, overheating of the EGR cooling unit can be suppressed.

  In order to achieve the above object, a cooling device according to the present invention is (3) a cooling device that includes an internal combustion engine and a rotating electrical machine, and is applied to a hybrid vehicle that uses at least one of the internal combustion engine and the rotating electrical machine as a travel source. A heat exchanger that exchanges heat between the refrigerant and the outside air, and a first circulation passage that circulates the refrigerant discharged from the heat exchanger to cool the internal combustion engine. And cooling the exhaust gas recirculated by an EGR device that branches from the first circulation flow path and recirculates part of the exhaust gas discharged from the internal combustion engine to the intake passage of the internal combustion engine. A third cooling section in which a third circulation flow path for circulating the refrigerant is formed; a refrigerant circulation means provided on the third circulation flow path for forcibly circulating the refrigerant; and the internal combustion engine. After cooling The second refrigerant temperature detecting means for detecting the temperature of the refrigerant, the EGR stop determining means for determining whether or not the exhaust gas recirculation by the EGR device has stopped, and the second refrigerant temperature detecting means are detected. When the temperature of the refrigerant exceeds a predetermined third threshold value, the refrigerant circulation means is controlled to circulate the refrigerant, while the exhaust gas recirculation by the EGR device is stopped by the EGR stop determination means. And a control means for controlling the refrigerant circulation means to stop the refrigerant circulation when a predetermined time has elapsed after the exhaust gas recirculation is stopped by the EGR device. Is done.

  With this configuration, when the temperature of the refrigerant detected by the second refrigerant temperature detection unit exceeds a predetermined third threshold, the control unit controls the refrigerant circulation unit to circulate the refrigerant. During normal driving in an urban area or the like after completion of engine warm-up, the exhaust gas recirculated by the EGR device can be cooled by using the surplus cooling capacity of the cooling device. Thereby, the intake air sucked into the internal combustion engine including the exhaust gas to be recirculated is cooled. For this reason, during normal traveling, the temperature rise in the combustion chamber of the internal combustion engine can be suppressed by utilizing the excess cooling capacity, and the occurrence of knocking due to the temperature rise in the combustion chamber can be prevented. .

On the other hand, after the EGR stop determining means determines that the recirculation of the exhaust gas by the EGR device has stopped, the control means controls the EGR refrigerant circulation means to stop the refrigerant circulation, so that, for example, a load applied to the internal combustion engine is increased. In the case of uphill traveling that increases compared to normal traveling, the cooling of the internal combustion engine that is originally required can be performed with priority over the cooling of the intake air. In addition, since the circulation of the refrigerant in the third cooling unit is stopped when a predetermined time has elapsed after the exhaust gas recirculation by the EGR device is stopped, overheating of the third cooling unit can be suppressed.
The third threshold value is, for example, a refrigerant when warmed up until the internal combustion engine can perform stable combustion even when a part of the exhaust discharged from the internal combustion engine is recirculated to the intake passage of the internal combustion engine. Set to the temperature of.

  According to the present invention, it is possible to efficiently prevent the occurrence of knocking due to the temperature rise in the combustion chamber of the internal combustion engine during normal traveling or the like by using the surplus cooling capacity without impairing the cooling effect of the internal combustion engine. It is possible to provide a cooling device that can

1 is a schematic configuration diagram showing an outline of a hybrid vehicle to which an engine cooling device according to a first embodiment of the present invention is applied. It is a schematic structure figure showing the outline of the engine cooling device concerning a 1st embodiment of the present invention. It is a perspective view explaining the structure of the intake water cooling spacer in the engine cooling device which concerns on the 1st Embodiment of this invention. It is a fragmentary sectional view of an engine explaining the composition of the intake water cooling spacer in the engine cooling device concerning a 1st embodiment of the present invention. It is a figure explaining the structure of the intake water cooling spacer in the engine cooling device which concerns on the 1st Embodiment of this invention, (a) is a front view of an intake water cooling spacer, (b) is an expansion of an intake water cooling spacer. It is a side view. It is a graph which shows water warm-up property in A mode. It is a graph which shows water warm-up property in B mode. It is a flowchart which shows the intake air cooling control performed in the engine cooling device which concerns on the 1st Embodiment of this invention. It is a schematic block diagram which shows the outline of the EGR apparatus in the engine cooling device which concerns on the 2nd Embodiment of this invention. It is a schematic block diagram which shows the outline of the cooling device for engines which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows the intake air cooling control performed in the engine cooling device which concerns on the 2nd Embodiment of this invention. It is a schematic block diagram which shows the outline of the cooling device for engines which concerns on the 3rd Embodiment of this invention. It is a flowchart which shows the EGR cooling control performed in the engine cooling device which concerns on the 3rd Embodiment of this invention. It is a graph which shows the engine operating line applied to the vehicle which employ | adopts a hybrid system.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
A hybrid vehicle 1 to which an engine cooling device 40 according to a first embodiment of the present invention is applied will be described with reference to FIG.

  As shown in FIG. 1, a hybrid vehicle 1 includes an engine 2 as an internal combustion engine, a motor generator MG1 and a motor generator MG2 as rotating electric machines, a power split device 4, a differential gear 5, a gear 6 and a gear 7. A battery B, a boosting unit 8, an inverter 9, a control unit 10, front wheels 12R, 12L, rear wheels 13R, 13L, a radiator 15 for electric equipment, and a cooling device 20 including a radiator 16 for engine. It is configured to include.

  The engine 2 has a plurality of cylinders (not shown), and employs a so-called Atkinson cycle in which the expansion ratio is higher than the actual compression ratio to increase the thermal efficiency. Further, the engine 2 includes a cylinder head and a cylinder block (not shown), and a water jacket (not shown) is formed in the cylinder head and the cylinder block so that cooling water, which will be described later, is circulated. Yes.

  The motor generator MG1 is connected to the engine 2 via the power split device 4, and functions mainly as a generator when driven by the engine 2 and also functions as a starter motor when the engine 2 is started. The electric power generated by motor generator MG1 is stored in battery B via inverter 9 and booster unit 8, and is used for driving motor generator MG2.

  The motor generator MG2 has a motor rotation shaft connected to the power split device 4, and assists the engine 2 to drive the front wheels 12R and 12L via the differential gear 5. In addition, when the hybrid vehicle 1 is braked, the motor generator MG2 functions as a generator to generate regenerative power by converting rotational energy of the front wheels 12R and 12L into electric energy. The obtained electric energy is stored in the battery B through the inverter 9 and the booster unit 8.

  Power split device 4 is constituted by a planetary gear device, and is arranged between engine 2 and motor generator MG2. The power split device 4 splits power among the engine 2, the motor generator MG1, and the motor generator MG2. Therefore, the power split device 4 controls the vehicle speed by driving the motor generator MG2 by controlling the power generation amount of the motor generator MG1 while operating the engine 2 in the most efficient region, and the energy efficiency as a whole is improved. A good hybrid vehicle 1 is realized.

  Further, the power of the engine 2 and the motor generator MG2 as the travel source transmitted through the power split device 4 is transmitted to the differential gear 5 through the gear 6 and the gear 7, and the front wheels 12R and 12L are transmitted from the differential gear 5. To be communicated to.

  The battery B is composed of, for example, a secondary battery such as nickel metal hydride or lithium ion, and functions as a DC power source. The battery B supplies DC power to the boosting unit 8 and is charged by DC power supplied from the boosting unit 8. Further, the battery B is configured to include a plurality of battery units B0 to Bn connected in series so that a high voltage is ensured.

The boosting unit 8 is connected to the battery B and the inverter 9, boosts the DC voltage received from the battery B, and supplies the boosted DC voltage to the inverter 9. Further, the booster unit 8 converts the DC voltage supplied from the inverter 9 into a voltage suitable for charging the battery B and supplies the converted voltage to the battery B. Thereby, the battery B is charged.
In addition, system main relays 8a and 8b are provided between the boosting unit 8 and the battery B so that the supply of a high voltage is cut off when the vehicle is not in operation.

The inverter 9 is connected to the motor generator MG1 and the motor generator MG2 and the boosting unit 8, and performs conversion between AC power and DC power. For example, when the engine 2 is started, the DC voltage supplied from the booster unit 8 is converted into an AC voltage, and the motor generator MG1 is driven and controlled. On the other hand, after engine 2 is started, inverter 9 converts AC power generated by motor generator MG1 into DC power and supplies it to boosting unit 8.
Further, the inverter 9 drives and controls the motor generator MG2.

  The control unit 10 includes a microcomputer including a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), an input / output interface, and the like. The CPU is a temporary storage function of the RAM. And signal processing is performed in accordance with a program stored in advance in the ROM. By this signal processing, the control unit 10 causes the engine 2, the inverter 9, the boosting unit 8, the system main relays 8a and 8b, and the cooling device in accordance with the driver's instructions and outputs from various sensors provided in the hybrid vehicle 1. 20 controls are performed. Therefore, the control unit 10 constitutes the hybrid vehicle 1 and also constitutes the cooling device 20.

  In addition, for example, an accelerator pedal position sensor or a vehicle speed sensor that detects the amount of depression of an accelerator pedal is connected to the control unit 10 as described above, and the control unit 10 opens an accelerator that is input from the accelerator pedal position sensor. The required torque is calculated based on the degree Acc and the vehicle speed V detected based on the input signal from the vehicle speed sensor, and the engine 2, the motor generator MG1, and the motor generator MG2 are output so that the power corresponding to the required torque is output. It comes to control.

Further, an ignition device and a fuel injection device (not shown) are connected to the control unit 10, and the engine 2 is started or stopped by grasping the state of the ignition device and the fuel injection device. It is designed to determine whether it has been done. In addition, the control unit 10 may determine whether the engine 2 is started or stopped based on, for example, the engine speed.
Moreover, the control part 10 performs warming-up of the engine 2 mentioned later according to the temperature of the cooling water which passed the water jacket in the engine 2. FIG.

  The cooling device 20 includes an electric device cooling device 30 including the electric device radiator 15 and an engine cooling device 40 including the engine radiator 16.

  The electric device cooling device 30 is provided separately from the engine cooling device 40, and includes an electric device radiator 15, an electric device water pump (not shown), an electric motor that drives the electric device water pump, and the like. Yes. The electric device cooling apparatus 30 configured as described above includes a cooling water passage 30a between the electric device radiator 15 and the inverter 9, the motor generator MG1, and the motor generator MG2 as electric devices by a water pump for electric devices. Cooling water as a refrigerant is circulated through the. That is, in the cooling device 30 for electric equipment, the cooling water circulating in the cooling water passage 30a takes heat generated by the inverter 9, the motor generator MG1 and the motor generator MG2, and dissipates heat to the outside air by the electric equipment radiator 15. The inverter 9, the motor generator MG1, and the motor generator MG2 are cooled.

  In addition to the inverter 9, the motor generator MG1, and the motor generator MG2, the electric device cooling apparatus 30 may cool the boosting unit 8, the control unit 10, and the battery B, for example, as electric devices.

  The engine cooling device 40 is provided separately from the electric device cooling device 30 and includes the engine radiator 16 and an engine water pump described later. The engine cooling device 40 configured as described above is a cooling water as a refrigerant discharged from the engine radiator 16 via the cooling water passage 40a by the engine water pump between the engine radiator 16 and the engine 2. Is being circulated. That is, the engine cooling device 40 is configured so that the cooling water circulating in the cooling water passage 40a takes heat generated by the engine 2 and dissipates heat to the outside air by the engine radiator 16, thereby cooling the engine 2 described above. It has become. Therefore, engine cooling device 40 according to the present embodiment constitutes a cooling device according to the present invention.

Next, with reference to FIG. 2, the engine cooling device 40 according to the first embodiment of the present invention will be described in detail.
As shown in FIG. 2, the engine cooling device 40 includes an engine cooling unit 50, an intake air cooling unit 60, an engine radiator 16 shared by the engine cooling unit 50 and the intake air cooling unit 60, and a radiator outlet water temperature sensor. 64, an engine outlet water temperature sensor 65, and the control unit 10. The engine cooling unit 50 of the engine cooling device 40 according to the present embodiment constitutes a first cooling unit in the cooling device according to the present invention, and the intake air cooling unit 60 constitutes a second cooling unit. The radiator 16 constitutes a heat exchanger, the radiator outlet water temperature sensor 64 constitutes a first refrigerant temperature detecting means, the engine outlet water temperature sensor 65 constitutes a second refrigerant temperature detecting means, and a control unit 10 constitutes a control means.

The engine cooling unit 50 includes a thermostat 51, an engine water pump 52, and a heater core 53. Between the thermostat 51, the engine water pump 52 and the heater core 53, and the engine radiator 16, Cooling water is circulated through an engine cooling water passage 54, a bypass passage 56, and a heater core cooling water passage 58, which will be described later, constituting a part of the cooling water passage 40a (see FIG. 1).
Here, the engine coolant passage 54 is connected to the engine 2 via a flow path 54a through which coolant flowing from the radiator outlet 16a of the engine radiator 16 to the thermostat 51 flows, and from the thermostat 51 via the engine water pump 52. A flow path 54b through which cooling water that flows to the engine outlet 2a passes through a water jacket formed in a cylinder block or cylinder head (not shown) that constitutes the engine, and a radiator inlet of the engine radiator 16 from the engine outlet 2a. It is comprised from the flow path 54c through which the cooling water which flows into the part 16b distribute | circulates. Further, the bypass passage 56 circulates the cooling water that has branched from the flow path 54 c of the engine outlet portion 2 a and has flowed through the engine 2 to the thermostat 51. The heater core cooling water passage 58 includes a flow path 58a through which cooling water flowing from the engine outlet 2a to the heater core 53 flows, and a flow path 58b through which cooling water flowing from the heater core 53 to the thermostat 51 flows. ing. The engine coolant passage 54 of the engine cooling device 40 according to the present embodiment constitutes a first circulation channel of the cooling device according to the present invention.

  The thermostat 51 is provided in an engine coolant passage 54 between the engine radiator 16 and the engine water pump 52, and a valve body that opens and closes according to the temperature of the coolant is provided therein. When the temperature of the cooling water is equal to or lower than a predetermined value, that is, when the engine 2 is warmed up, the thermostat 51 closes the valve body to cut off the communication between the flow path 54a and the flow path 54b and also bypass the bypass passage 56. And the flow path 54b are communicated with each other. Therefore, when the engine 2 is warmed up, the cooling water circulating in the engine cooling water passage 54 is circulated again toward the engine 2 through the bypass passage 56 without circulating through the engine radiator 16. It has become. For this reason, the temperature of the cooling water in the engine 2 can be quickly raised, and the warm-up of the engine 2 can be promoted.

On the other hand, in the thermostat 51, when the temperature of the cooling water exceeds a predetermined value, that is, after the warm-up of the engine 2 is completed, the valve body is opened so that the flow path 54a and the flow path 54b are communicated. Yes. Therefore, when the temperature of the cooling water rises to an appropriate value, the cooling water circulating in the bypass passage 56 circulates through the engine radiator 16 via the engine cooling water passage 54, and the engine The heat of the cooling water that has become high temperature by circulating in the engine 2 is radiated from the engine radiator 16 to the outside air.
Therefore, the engine cooling unit 50 is configured so that when the coolant circulated through the engine coolant passage 54 circulates in a water jacket formed in a cylinder block or a cylinder head (not shown) constituting the engine 2, The engine 2 is cooled by depriving the heat generated in the engine 2 and exchanging heat with the outside air in the engine radiator 16.

  Here, the thermostat 51 is configured to be mechanically openable or closeable according to the temperature of the cooling water. However, the thermostat 51 is not limited thereto, and has, for example, a control valve electrically connected to the controller. And it is good also as a structure which can be opened or closed according to the signal from a control part.

  The engine water pump 52 is connected to a crankshaft (not shown) of the engine 2 through, for example, a drive belt, and is driven according to the rotation of the crankshaft of the engine 2. The engine water pump 52 may be driven by a drive source different from the engine 2, for example, an electric motor.

  The heater core 53 is provided on the heater core cooling water passage 58 between the flow passage 54c of the engine outlet portion 2a and the thermostat 51, and is provided by branching from the engine cooling water passage 54 of the engine outlet portion 2a. Cooling water having a high temperature in the engine 2 is introduced through 58a. The high-temperature cooling water introduced into the heater core 53 is used for heating the interior of the hybrid vehicle 1.

The intake air cooling unit 60 is provided independently of the engine cooling unit 50 described above, and includes an electric water pump 61 and an intake water cooling spacer 62. The intake air cooling unit 60 is connected to the electric water pump 61, the intake water cooling spacer 62, and the engine radiator 16 via an intake cooling water passage 66 constituting a part of the cooling water passage 40a (see FIG. 1). Cooling water is circulated. That is, the intake air cooling unit 60 cools the intake air introduced into the combustion chamber of the engine 2 when the cooling water circulated through the intake cooling water passage 66 flows through the intake water cooling spacer 62. It has become.
Here, the intake cooling water passage 66 is branched from the flow passage 54a of the engine cooling water passage 54, and the flow passage 66a through which the cooling water flowing from the radiator outlet 16a to the electric water pump 61 circulates, and the electric water. A flow path 66b through which cooling water that flows from the pump 61 to the intake water cooling spacer 62 flows, and a flow path 66c through which cooling water that flows from the intake water cooling spacer 62 to the radiator inlet 16b flows. The intake cooling water passage 66 of the engine cooling device 40 according to the present embodiment constitutes a second circulation channel of the cooling device according to the present invention.

  The electric water pump 61 is provided in the intake cooling water passage 66 between the radiator outlet 16a and the intake water cooling spacer 62, and has a drive motor 61a. The electric water pump 61 is configured to either circulate the cooling water or stop the circulation when the drive of the drive motor 61a is controlled by the control unit 10. Therefore, the electric water pump 61 of the engine cooling device 40 according to the present embodiment constitutes the refrigerant circulation means according to the present invention.

  The intake water cooling spacer 62 is provided in an intake cooling water passage 66 between the electric water pump 61 and the radiator inlet 16b, and is cooled by the electric water pump 61 from the engine radiator 16 through the flow paths 66a and 66b. Water has been distributed. Therefore, the intake water cooling spacer 62 cools the intake air introduced into the engine 2 through an intake port, which will be described later, with the coolant that is circulated.

  Specifically, as shown in FIGS. 3 and 4, the intake water cooling spacer 62 includes a plurality of bolts 72 and a plurality of bolts between the cylinder head 2 c of the engine 2 in which the intake port 2 b is formed and the intake manifold 71. The nut 73 is attached.

  Further, as shown in FIGS. 5A and 5B, the intake water cooling spacer 62 has a plurality of intake air flows corresponding to the plurality of intake passages 71a (see FIG. 4) of the intake manifold 71. A passage 62a is formed. Further, a cooling water flow path 62b is formed inside the intake water cooling spacer 62 so that the inside of the intake water cooling spacer 62 is hollow. The cooling water flow path 62b includes a cooling water inlet 62c and a cooling water outlet 62d. Via the flow path 66b and the flow path 66c (see FIG. 2) of the intake cooling water passage 66. Therefore, the cooling water circulating in the intake cooling water passage 66 flows through the intake water cooling spacer 62 via the cooling water flow path 62b, and cools the intake air introduced into the engine 2. Then, the heat of the cooling water after cooling the intake air is introduced into the engine radiator 16 through the flow path 66c, and is radiated from the engine radiator 16 into the outside air.

  As shown in FIG. 2, the radiator outlet water temperature sensor 64 is provided in the vicinity of the radiator outlet portion 16 a, and the electric water pump 61 passes through the flow path 66 a and the flow path 66 b of the intake cooling water passage 66 from the engine radiator 16. The cooling water flowing through the intake water cooling spacer 62, that is, the temperature of the cooling water discharged from the radiator outlet 16a after being radiated into the outside air by the engine radiator 16 (hereinafter simply referred to as the radiator water temperature Tr) is detected. It has become. Further, the radiator outlet water temperature sensor 64 outputs a signal corresponding to the detected radiator water temperature Tr to the control unit 10.

  Although not shown, the engine outlet water temperature sensor 65 is provided in the flow path 54c of the engine outlet portion 2a, and the cooling water after flowing through the water jacket of the engine 2, that is, the cooling after taking the heat of the engine 2 is removed. The temperature of water (hereinafter simply referred to as engine water temperature Te) is detected. The engine outlet water temperature sensor 65 outputs a signal corresponding to the detected engine water temperature Te to the control unit 10. In the present embodiment, the engine outlet water temperature sensor 65 is provided in the flow path 54c of the engine outlet portion 2a. However, the present invention is not limited to this. For example, the engine outlet water temperature sensor 65 is provided in the flow path 54b of the engine outlet portion 2a. May be.

  The control unit 10 is connected to a drive motor 61 a that drives the electric water pump 61, a radiator outlet water temperature sensor 64, and an engine outlet water temperature sensor 65, and the radiator outlet water temperature sensor 64 and the engine outlet water temperature sensor 65 are connected to the radiator water temperature Tr. The radiator water temperature Tr and the engine water temperature Te are detected by inputting a signal corresponding to the engine water temperature Te. Further, a temperature sensor of an exhaust purification device (not shown) is connected to the control unit 10, and a signal corresponding to the catalyst temperature is input from this temperature sensor.

  Based on the engine water temperature Te detected by the engine outlet water temperature sensor 65, the control unit 10 determines whether or not the engine 2 needs to be warmed up, particularly the intake port 2b. For example, whether or not the estimated wall temperature (° C.) of the intake port 2b of the engine 2 has reached a predetermined temperature (° C.) is determined based on the engine water temperature Te (° C.) described above. When the controller 10 determines that the estimated wall temperature of the intake port 2b of the engine 2 estimated by the engine coolant temperature Te has not reached the predetermined temperature, the controller 10 warms up the engine 2. Here, the warm-up of the engine 2 described above is performed, for example, by executing control such as increasing the fuel injection amount by the fuel injection device in order to increase the combustion temperature.

  Further, the control unit 10 determines whether or not the warm-up of the engine 2, particularly the warm-up of the intake port 2b, has been completed based on the engine coolant temperature Te. That is, the control unit 10 determines whether or not the estimated wall temperature of the intake port 2b of the engine 2 has reached a predetermined temperature based on the engine water temperature Te described above, and the intake port 2b of the engine 2 estimated based on the engine water temperature Te. When it is determined that the estimated wall temperature has reached a predetermined temperature, it is determined that the warm-up of the engine 2 has been completed.

  Further, the control unit 10 determines whether or not the above-described warming up of the engine 2 has been completed, whether or not it is necessary to warm up the catalyst of an exhaust purification device (not shown), and whether or not the warming up of the catalyst has been completed. It is determined whether or not. For example, the control unit 10 determines a predetermined time during which it can be estimated that the temperature of the catalyst is equal to or higher than the activation temperature that is experimentally obtained and stored in advance, or that the catalyst temperature has reached the activation temperature after the engine 2 is started. Whether or not the catalyst needs to be warmed up and whether or not the catalyst has been warmed up are determined based on whether or not the time has elapsed. In addition, for example, based on the engine coolant temperature Te, it may be determined whether the catalyst needs to be warmed up and whether the catalyst has been warmed up.

  The above-described warming-up of the catalyst is performed, for example, by executing control for retarding the ignition timing from the normal ignition timing, that is, so-called ignition retard control, after the engine 2 is started. That is, by retarding the ignition timing, the combustion timing can be delayed, and combustion can be performed even during the exhaust stroke, and the temperature rise of the catalyst in the exhaust purification device can be promoted. The warming-up of the catalyst is not limited to the ignition delay control described above. For example, the temperature of the catalyst in the exhaust purification device is promoted by increasing the fuel injection amount by the fuel injection device to increase the combustion temperature. good.

  Further, the control unit 10 determines whether or not the radiator water temperature Tr (° C.) detected by the radiator outlet water temperature sensor 64 exceeds the radiator water temperature Trth (° C.) that has been experimentally obtained and stored in advance. ing. The above-mentioned radiator water temperature Trth is set to a radiator water temperature, for example, 80 ° C. that can be determined as a state in which the engine 2 has been warmed up and knocking can occur as the temperature of the engine 2 rises.

  In addition, when it is determined that the radiator water temperature Tr exceeds the above-described radiator water temperature Trth, the control unit 10 controls the drive motor 61a to drive the electric water pump 61, thereby cooling water in the intake air cooling unit 60. Is supposed to circulate.

Further, the control unit 10 determines whether or not the engine water temperature Te (° C.) detected by the engine outlet water temperature sensor 65 is equal to or higher than the engine water temperature Teth ₁ (° C.) that has been experimentally obtained and stored in advance. It has become. The engine water temperature Teth ₁ described above is higher than the radiator water temperature Trth described above, and is set to an engine water temperature, for example, 100 ° C., in which cooling of the engine 2 needs to be prioritized depending on the traveling state, for example, when traveling uphill. Is set.

Further, when it is determined that the engine water temperature Te is equal to or higher than the engine water temperature Teth ₁ , the control unit 10 controls the drive motor 61a to stop driving and stops the electric water pump 61, thereby The circulation of the cooling water in the cooling unit 60 is stopped.

Here, the radiator water temperature Trth of 80 ° C. and the engine water temperature Teth ₁ of 100 ° C. are examples, and the optimal radiator water temperature Trth and engine water temperature Teth are appropriately set according to the specifications of the hybrid vehicle 1 and the engine 2. Is done.

The radiator water temperature Trth in the engine cooling device 40 according to the present embodiment corresponds to the first threshold value in the cooling device according to the present invention, and the engine water temperature Teth ₁ described above is the cooling device according to the present invention. Corresponds to the second threshold.

  The control unit 10 is not limited to the above-described configuration. For example, the control unit 10 includes an engine control unit that performs control related to the engine 2 and a cooling control unit that is provided separately and performs control related to the cooling device 20. In this case, the engine control unit and the cooling control unit are connected so as to be capable of bidirectional communication.

Next, with reference to FIGS. 6-8, operation | movement of the engine cooling device 40 which concerns on the 1st Embodiment of this invention is demonstrated.
The engine cooling device 40 includes the engine cooling unit 50 and the intake air cooling unit 60 as described above, and the intake air cooling unit 60 operates when there is a surplus in the cooling capacity of the engine radiator 16. It has become.

First, with reference to FIG. 6 and FIG. 7, the surplus of the cooling capacity in the engine cooling device 40 according to the present embodiment will be described.
Here, FIG. 6 shows the completion of warm-up in A mode with the vehicle speed V (km / h), the engine water temperature Te (° C.) and the engine speed Ne (rpm) as the vertical axis and the time (sec) as the horizontal axis. It is a graph which shows the water warming property showing the transition characteristic of the engine water temperature until. The A mode is a vehicle travel mode that assumes a travel state when the vehicle actually travels in an urban area. Moreover, the dashed-dotted line G and the dashed-two dotted line D shown by FIG. 6 have shown each engine water temperature (degreeC) in the A mode of the conventional gasoline vehicle and diesel vehicle which do not employ | adopt a hybrid system, respectively. A thick broken line TeA ₀ and a thick solid line TeA ₁ both indicate the relationship between the time (sec) in the A mode of the hybrid vehicle employing the hybrid system and each engine water temperature (° C.), and in particular, the thick solid line TeA ₁ These show the relationship between the time (sec) in the A mode of the hybrid vehicle 1 according to the present embodiment and the engine coolant temperature Te (° C.).
A thin broken line VhA indicates a relationship between time (sec) and vehicle speed (km / h) in the A mode of the hybrid vehicle 1 according to the present embodiment, and a thin solid line HeA indicates a hybrid vehicle according to the present embodiment. 1 shows the relationship between time (sec) and engine speed Ne (rpm) in the A mode.

FIG. 7 shows the engine after completion of warm-up in the B mode with the vehicle speed (km / h), the engine water temperature (° C.) and the engine speed Ne (rpm) as the vertical axis and the time (sec) as the horizontal axis. It is a graph which shows water warm-up property showing transition of water temperature. The B mode is a vehicle travel mode that assumes a travel state when the vehicle actually travels in an urban area.
Here, the thick solid line TeB shown in FIG. 7 indicates the relationship between the time (sec) in the B mode of the hybrid vehicle 1 according to the present embodiment and the engine water temperature Te (° C.). A broken line VhB indicates the relationship between time (sec) and vehicle speed (km / h) in the B mode of the hybrid vehicle 1 according to the present embodiment, and a thin solid line HeB indicates the hybrid vehicle 1 according to the present embodiment. The relationship between the time (sec) in B mode and the engine speed Ne (rpm) is shown.

  As shown in FIG. 6, in the hybrid vehicle including the hybrid vehicle 1 according to the present embodiment, the engine is warmed up, the thermostat is opened, and the engine is cooled using the cooling capacity of the radiator. The engine water temperature to be started, for example, the time until the engine water temperature rises to 82 ° C. is longer than that of general gasoline vehicles and diesel vehicles. This is because in the hybrid vehicle, the thermal efficiency in the engine is enhanced by adopting the Atkinson cycle, like the engine 2 mounted in the hybrid vehicle 1 according to the present embodiment.

In addition, as shown in FIG. 7, the engine water temperature Te after the warm-up of the engine 2 mounted on the hybrid vehicle 1 according to the present embodiment is about 85 ° C. Compared with the engine water temperature after completion of the machine, for example, 90 to 95 ° C., the engine water temperature is low. Thus, the hybrid vehicle 1 shows that the engine 2 is efficiently cooled by the cooling water as compared with a general vehicle.
The engine water temperature Te in each of the above modes is appropriately set according to the specifications of the vehicle and the engine.

On the other hand, the cooling capacity of the engine radiator 16 (see FIG. 1) of the hybrid vehicle 1 according to the present embodiment is set to a cooling capacity that can sufficiently secure the cooling of the engine 2 during, for example, uphill traveling or ultra-high speed traveling. It is set up. The cooling capacity here represents heat dissipation performance and is indicated by a heat dissipation amount kW. Further, the cooling capacity of the engine radiator 16 is appropriately set to an optimal cooling capacity according to the specifications of the vehicle and the engine. For example, the cooling capacity is set to about 20 kW at a vehicle speed of 35 km / h, and about 50 kW at a vehicle speed of 180 km / h. . However, during normal driving such as urban driving, the engine water temperature Te is kept relatively low with time as shown in FIG. The cooling capacity of the radiator 16 is much smaller than the preset cooling capacity described above. For example, the amount of heat released from the engine radiator 16 during normal running is about several kW.
Therefore, during the normal running described above, the cooling capacity of the engine cooling device 40 (see FIG. 2) including the engine radiator 16 is surplus.

  On the other hand, a general hybrid vehicle engine employing a hybrid system is used in a high load region where the engine torque (N · m) is high as shown in FIG. There is a risk of being prone to occur.

  Therefore, in the present embodiment, as described above, in the engine cooling device 40, the intake air cooling unit 60 configured by the cooling system independent of the engine cooling unit 50 is provided, and the surplus cooling capacity is provided to the intake air cooling unit. By using at 60, occurrence of knocking during normal travel of the hybrid vehicle 1 described above can be suitably prevented.

  Hereinafter, in order to prevent the occurrence of knocking during normal traveling by using the above-described surplus cooling capacity, intake air cooling control executed in the control unit 10 (see FIG. 1) of the hybrid vehicle 1 and the engine cooling device 40 Will be described.

  The flowchart shown in FIG. 8 shows the execution contents of the processing program for intake air cooling control stored in the ROM of the control unit 10, and this processing program includes a single program or a plurality of programs for executing the control contents. Has been. The processing program for the intake air cooling control is executed by the CPU of the control unit 10 at predetermined time intervals.

As shown in FIG. 8, the control unit 10 determines whether or not the engine 2 has been started by grasping the states of the ignition device and the fuel injection device (step S101).
If it is determined by the control unit 10 that the engine 2 has been started (YES in step S101), the control unit 10 determines whether warm-up is necessary (step S102). Specifically, the control unit 10 determines whether or not the engine 2 needs to be warmed up, such as warming up of the intake port 2b, based on the engine water temperature Te, and whether or not the catalyst of the exhaust emission control device needs to be warmed up. Is determined based on the catalyst temperature. When it is determined that the engine 2 needs to be warmed up and the catalyst needs to be warmed up (YES in step S102), the control unit 10 performs the warming up of the engine 2 and the catalyst (step S103). On the other hand, when it is determined that the engine 2 has not been started (NO in step S101), the control unit 10 repeats the process of step S101 again.

  Next, the control unit 10 determines whether or not the warming up of the engine 2 and the warming up of the catalyst executed in step S103 are completed (step S104). Specifically, the control unit 10 determines whether or not the estimated wall temperature estimated from the engine water temperature Te of the cylinder head 2c surrounding the intake port 2b of the engine 2 has reached a predetermined temperature based on the engine water temperature Te described above. Thus, it is determined whether or not the engine 2 has been warmed up. In addition, the control unit 10 can estimate that the catalyst temperature is equal to or higher than the catalyst activation temperature that has been experimentally obtained in advance and stored, or that the catalyst temperature has reached the activation temperature after the engine 2 is started. It is determined whether or not the warm-up of the catalyst is completed depending on whether or not the time has elapsed.

  When it is determined that the engine 2 has been warmed up and the catalyst has been warmed up (YES in step S104), the control unit 10 proceeds to step S105. When it is determined that the engine 2 is not warmed up and the catalyst is not warmed up (NO in step S104), the controller 10 determines that the engine 2 is warmed up and the catalyst is warmed up. Until the process of step S104 is repeated.

On the other hand, when it is determined in step S102 that the engine 2 is not warmed up and the catalyst is not warmed up (NO in step S102), the control unit 10 executes the processes in steps S103 and S104 described above. Instead, the process proceeds to step S105.
Next, the control unit 10 detects the radiator water temperature Tr together with the radiator outlet water temperature sensor 64 (step S105).

  Next, the control unit 10 determines whether or not the radiator water temperature Tr detected by the radiator outlet water temperature sensor 64 has exceeded the radiator water temperature Trth (step S106). When it is determined that the radiator water temperature Tr detected by the radiator outlet water temperature sensor 64 does not exceed the radiator water temperature Trth (NO in step S106), the control unit 10 performs the processes in steps S107 to S110 subsequent to step S106. The process proceeds to step S111 without executing.

On the other hand, when it is determined that the radiator water temperature Tr detected by the radiator outlet water temperature sensor 64 has exceeded the radiator water temperature Trth (YES in step S106), the control unit 10 controls the drive motor 61a to control the electric water pump 61. Is driven (step S107). Therefore, the cooling water is circulated in the intake air cooling unit 60.
Next, the control unit 10 detects the engine water temperature Te together with the engine outlet water temperature sensor 65 (step S108).

Next, the control unit 10 determines whether or not the engine water temperature Te detected by the engine outlet water temperature sensor 65 is equal to or higher than the engine water temperature Teth ₁ (step S109). When it is determined that the engine coolant temperature Te is lower than the engine coolant temperature Teth ₁ (NO in step S109), the control unit 10 returns to step S108 and determines that the engine coolant temperature Te is equal to or higher than the engine coolant temperature Teth ₁ described above. Steps S108 and S109 are repeated until it is done.

On the other hand, when it is determined that the engine water temperature Te is equal to or higher than the above-described engine water temperature Teth ₁ (YES in step S109), the control unit 10 controls the drive motor 61a to stop driving the electric water pump 61. By stopping, circulation of the cooling water in the intake air cooling unit 60 is stopped (step S110).

Next, the control unit 10 determines whether or not the engine 2 has been stopped by grasping the states of the ignition device and the fuel injection device (step S111). If the control unit 10 determines that the engine 2 is not stopped (NO in step S111), the control unit 10 returns to step S105, and executes the processing in steps S105 to S111 again.
On the other hand, when it is determined that the engine 2 has stopped (YES in step S111), the control unit 10 ends this process.

  Since the engine cooling device 40 according to the present embodiment is configured as described above, the following effects can be obtained.

  When the radiator water temperature Tr detected by the radiator outlet water temperature sensor 64 and the control unit 10 exceeds the radiator water temperature Trth, the control unit 10 controls the electric water pump 61 to circulate the cooling water in the intake air cooling unit 60. For example, during normal travel in an urban area or the like after completion of warm-up of the engine 2, the intake air sucked into the engine 2 can be cooled using the surplus cooling capacity of the engine cooling device 40.

  For this reason, during normal traveling, the temperature rise in the combustion chamber of the engine 2 can be suppressed while maintaining sufficient cooling of each cylinder of the engine 2 by utilizing the surplus of the cooling capacity. The occurrence of knocking due to temperature rise can be prevented.

On the other hand, when the engine water temperature Te detected by the engine outlet water temperature sensor 65 and the control unit 10 becomes equal to or higher than the engine water temperature Teth _{1 that is} higher than the radiator water temperature Trth, the control unit 10 circulates the cooling water in the intake air cooling unit 60. Since the electric water pump 61 is controlled so as to be stopped, for example, in the case of uphill running in which the load applied to the engine 2 is increased as compared with that during normal running, the cooling of each cylinder of the engine 2 that is originally required is performed. Can be prioritized for cooling the intake air.

  The drive format of the hybrid vehicle 1 to which the engine cooling device 40 according to the present embodiment is applied is not limited to the drive format of the present embodiment. For example, an internal combustion engine is used for power generation and the power generation is performed. Other hybrid drive formats such as a so-called series type drive format in which the wheels are driven by driving the electric motor using the electric power, or a so-called parallel drive format in which the wheels are driven by the internal combustion engine and the electric motor may be used. .

(Second Embodiment)
Next, a hybrid vehicle 100 to which the engine cooling apparatus 140 according to the second embodiment of the present invention is applied will be described with reference to FIGS. 1 and 9 to 11.

  In engine cooling device 140 for hybrid vehicle 100 according to the second embodiment of the present invention, an EGR device 130 and an engine cooling device 40 for hybrid vehicle 1 according to the first embodiment of the present invention, which will be described later, and Although different in that the EGR cooler 135 is further provided, other configurations are configured in the same manner. Therefore, the same configuration will be described using the same reference numerals as those in the first embodiment shown in FIGS. 1 to 8, and only differences will be described in detail.

  As shown in FIG. 1, hybrid vehicle 100 includes an engine 102 as an internal combustion engine, motor generator MG1 and motor generator MG2 as rotating electrical machines, power split device 4, differential gear 5, gear 6 and gear 7. A battery B, a boosting unit 8, an inverter 9, a control unit 110, front wheels 12R and 12L, rear wheels 13R and 13L, a radiator 15 for electric equipment, and a cooling device 120 including a radiator 16 for an engine. It is configured to include.

  The engine 102 includes an exhaust gas recirculation device, a so-called EGR (Exhaust Gas Recirculation) device 130, in addition to the configuration of the engine 2 in the first embodiment.

  As shown in FIG. 9, the EGR device 130 recirculates a part of the exhaust discharged from the combustion chamber 102 d of the engine 102 through the exhaust passage 103 to the intake passage 104 of the engine 102. The EGR device 130 includes an EGR pipe 131, an EGR valve 132, and a control unit 110. Therefore, the EGR device 130 according to the present embodiment constitutes an EGR device in the cooling device according to the present invention, and the control unit 110 constitutes an EGR stop determination unit.

  The EGR pipe 131 has an EGR passage 131a formed therein, and the EGR passage 131a communicates the exhaust passage 103 and the intake passage 104 with a part of the exhaust discharged from the engine 102 being exhausted. It has a function of recirculating to the intake passage 104 of the engine 102, that is, the intake side.

  The EGR valve 132 is provided on the EGR passage 131a, and is opened and closed steplessly in response to a signal from the control unit 110, so that the flow rate of the exhaust gas recirculating through the EGR passage 131a is adjusted.

  The EGR pipe 131 of the EGR device 130 is provided with an EGR cooler 135 described later. The EGR cooler 135 according to the present embodiment constitutes an EGR cooling unit in the cooling device according to the present invention.

  Control unit 110 responds to the driver's instructions and outputs from various sensors provided in hybrid vehicle 100, and engine 102, inverter 9, boosting unit 8, system main relays 8a and 8b, cooling device 120, and EGR device 130. Control is to be performed. Therefore, the control unit 110 constitutes the hybrid vehicle 100 and also constitutes the cooling device 120 and the EGR device 130.

  The control unit 110 is an EGR device out of the total intake air amount (g / rev, g is mass, rev is 360 degrees crank angle, that is, one rotation of the crankshaft) sucked into the cylinder of the engine 102. The EGR rate (%), which is the ratio of exhaust gas recirculated by the engine 130 (hereinafter referred to as EGR gas), is calculated, and the operating state of the engine 102, for example, the required torque (N · m) or the vehicle speed V (km / h) ) To set a target EGR rate (%) as a target. Here, this EGR rate is calculated as EGR rate = Gegr / Gcyl, where Gcyl is the intake air sucked into the cylinder and Gegr is the amount of EGR gas.

  In addition, the control unit 110 controls the EGR valve 132 so as to open only by an opening degree (deg) corresponding to the above-described target EGR rate.

Further, the control unit 110 determines whether or not the engine water temperature Te exceeds the engine water temperature Teth ₂ that has been experimentally obtained and stored in advance. Here, when the engine coolant temperature Te does not exceed the engine coolant temperature Teth ₂ , the controller 110 sets the target EGR rate to “0” because the combustion state deteriorates when the exhaust gas is recirculated to the intake side. A part of the exhaust is not recirculated to the intake passage 104 of the engine 102. On the other hand, when it is determined that the engine water temperature Te has exceeded the engine water temperature Teth ₂ , the control unit 110 determines that the combustion state does not deteriorate even if the exhaust gas is recirculated to the intake side, and the exhaust by the EGR device 130 is determined. Is determined to be possible. Further, when the control unit 110 determines that the engine water temperature Te has become equal to or lower than the engine water temperature Teth ₂ after the exhaust gas recirculation by the EGR device 130 is started, the exhaust gas recirculation by the EGR device 130 is stopped. It comes to judge.

The engine water temperature Teth ₂ described above is the engine water temperature when the engine 102 is warmed up until stable combustion can be performed even when a part of the exhaust discharged from the engine 102 is recirculated to the intake side of the engine 102. For example, it is set to 70 ° C.

  The EGR device 130 configured as described above recirculates a part of the exhaust discharged from the engine 102 to the intake passage 104, thereby suppressing the occurrence of pumping loss and improving fuel efficiency. Further, the exhaust gas is recirculated to reduce the oxygen ratio by mixing with a new air-fuel mixture, thereby lowering the combustion temperature and suppressing the generation of nitrogen oxides (NOx).

  As shown in FIG. 1, the cooling device 120 includes an electric device cooling device 30 including the electric device radiator 15, and an engine cooling device 140 including the engine radiator 16 and the EGR cooler 135.

  The engine cooling device 140 is provided separately from the electric device cooling device 30 and includes the engine radiator 16, the EGR cooler 135, the engine water pump 52, and the like. The engine cooling device 140 configured as described above includes an engine cooling water passage 54 and a bypass passage that constitute a part of the cooling water passage 140a by the engine water pump 52 between the engine radiator 16 and the engine 102. The cooling water discharged from the engine radiator 16 is circulated through the heater core cooling water passage 58. That is, the engine cooling device 140 is configured so that the cooling water circulating in the cooling water passage 140a takes heat generated by the engine 102 and dissipates heat to the outside air by the engine radiator 16, thereby cooling the engine 102 described above. It has become. Engine cooling device 140 according to the present embodiment constitutes a cooling device according to the present invention.

Next, an engine cooling apparatus 140 according to a second embodiment of the present invention will be described in detail with reference to FIG.
As shown in FIG. 10, the engine cooling device 140 includes an engine cooling unit 50, an intake air cooling unit 160, an engine radiator 16 shared by the engine cooling unit 50 and the intake air cooling unit 160, and a radiator outlet water temperature sensor. 64, an engine outlet water temperature sensor 65, and a control unit 110. The intake air cooling unit 160 of the engine cooling device 140 according to the present embodiment constitutes a second cooling unit in the cooling device according to the present invention, and the control unit 110 constitutes a control means.

The intake air cooling unit 160 is provided independently of the engine cooling unit 50 described above, and includes an electric water pump 61, an intake water cooling spacer 62, and an EGR cooler 135. The intake air cooling unit 160 includes the electric water pump 61, the intake water cooling spacer 62, the EGR cooler 135, and the cooling water passage 140a (see FIG. 1) that constitutes a part of the cooling water passage 140a (see FIG. 1). Cooling water is circulated through 166. That is, the intake air cooling unit 160 cools the intake air introduced into the combustion chamber 102d of the engine 2 when the cooling water circulated through the intake cooling water passage 166 flows in the intake water cooling spacer 62. In addition, the exhaust gas recirculated by the EGR device 130 is cooled.
Here, the intake cooling water passage 166 branches from the engine cooling water passage 54 a, and the intake water from the electric water pump 61 and the flow passage 166 a through which the cooling water flowing from the radiator outlet 16 a to the electric water pump 61 circulates. A flow path 166b through which cooling water flowing through the water cooling spacer 62 flows, a flow path 166c through which cooling water flowing from the intake water cooling spacer 62 to the EGR cooler 135 flows, and cooling water flowing from the EGR cooler 135 to the radiator inlet 16b. It is comprised from the flow path 166d which circulates. The intake cooling water passage 166 of the engine cooling device 140 according to the present embodiment constitutes a second circulation passage according to the present invention.

  The EGR cooler 135 is provided in the intake cooling water passage 166 between the intake water cooling spacer 62 and the radiator inlet 16b, and the cooling water is circulated from the engine radiator 16 via the electric water pump 61 and the intake water cooling spacer 62. It has become so. Thereby, the EGR cooler 135 cools the exhaust gas recirculated through the EGR passage 131a toward the intake passage 104 with the circulating coolant. By cooling the exhaust gas, the EGR cooler 135 reduces the volume of the flowing gas and can recirculate the exhaust gas having a higher density to the intake passage 104.

Further, similarly to the first embodiment, when it is determined that the radiator water temperature Tr exceeds the radiator water temperature Trth, the control unit 110 drives the electric water pump 61 by controlling the drive motor 61a, Cooling water is circulated in the intake air cooling unit 160.
The control unit 110, after the recirculation of exhaust gas by the EGR device 130 is stopped, so as to determine whether or not a predetermined time t ₁ has elapsed.

The control unit 110, it is determined that the recirculation of exhaust gas by the EGR device 130 is stopped, and after the recirculation of exhaust gas by the EGR device 130 is stopped, the driving of the driving motor 61a when a predetermined time t ₁ has elapsed The circulation of the cooling water in the intake air cooling unit 160 is stopped by stopping the electric water pump 61 by controlling to stop. The predetermined time t ₁ is set to a time sufficient for cooling the EGR cooler 135 and the EGR valve 132, for example.
The predetermined time t ₁ of the above in the engine cooling system 140 of the present embodiment constitutes a predetermined time in the cooling device according to the present invention.

  Next, with reference to FIG. 11, the intake air cooling control executed in the engine cooling apparatus 140 according to the second embodiment of the present invention will be described.

  The flowchart shown in FIG. 11 shows the execution contents of the processing program for intake air cooling control stored in the ROM of the control unit 110, and this processing program includes a single program or a plurality of programs for executing the control contents. Has been. The processing program for intake air cooling control is executed by the CPU of the control unit 110 at predetermined time intervals.

  As shown in FIG. 11, the control unit 110 determines whether or not the engine 102 has been started by grasping the states of the ignition device and the fuel injection device (step S <b> 201).

  If it is determined by the control unit 110 that the engine 102 has been started (YES in step S201), the control unit 110 determines whether warm-up is necessary (step S202). Specifically, the control unit 110 determines whether or not the engine 102 needs to be warmed up, such as warming up of the intake port 102b, based on the engine water temperature Te and whether or not the catalyst of the exhaust purification device needs to be warmed up. Is determined based on the catalyst temperature. When it is determined that the engine 102 needs to be warmed up and the catalyst needs to be warmed up (YES in step S202), control unit 110 performs warming up of engine 102 and catalyst (step S203). On the other hand, when it is determined that engine 102 has not been started (NO in step S201), control unit 110 repeats the process of step S201 again.

  Next, the control unit 110 determines whether or not the warming up of the engine 102 and the warming up of the catalyst executed in step S203 have been completed (step S204). Specifically, the control unit 110 determines whether or not the estimated wall temperature estimated from the engine water temperature Te of the cylinder head 102d surrounding the intake port 102b (see FIG. 4) of the engine 102 has reached a predetermined temperature. By determining based on the engine coolant temperature Te, it is determined whether or not the engine 102 has been warmed up. Further, the control unit 110 determines whether the catalyst temperature is equal to or higher than the activation temperature of the catalyst, or whether a predetermined time after which the catalyst temperature has reached the activation temperature has elapsed after the engine 102 is started. Determine whether the warm-up is complete.

  If controller 110 determines that warming up of engine 102 and warming up of the catalyst have been completed (YES in step S204), control proceeds to step S205. When it is determined that engine 102 has not been warmed up and catalyst has not been warmed up (NO in step S204), control unit 110 determines that engine 102 has been warmed up and catalyst has been warmed up. Until the process of step S204 is repeated.

  On the other hand, when it is determined in step S202 that the engine 102 and the catalyst need not be warmed up (NO in step S202), the control unit 110 executes the processes in steps S203 and S204 described above. Instead, the process proceeds to step S205.

Next, the controller 110 determines whether or not the exhaust gas recirculation by the EGR device 130 is possible (step S205). Specifically, the control unit 110 determines whether or not the exhaust gas recirculation by the EGR device 130 is possible by determining whether or not the engine water temperature Te has exceeded the engine water temperature Teth ₂ . When it is determined that the exhaust gas cannot be recirculated by the EGR device 130 (NO in step S205), the control unit 110 repeatedly executes the process of step S205 until it is determined that the exhaust gas can be recirculated.

  On the other hand, when it is determined that the exhaust gas recirculation by EGR device 130 is possible (YES in step S205), control unit 110 detects radiator water temperature Tr together with radiator outlet water temperature sensor 64 (step S206).

  Next, the control unit 110 determines whether or not the radiator water temperature Tr detected by the radiator outlet water temperature sensor 64 exceeds the radiator water temperature Trth (step S207). When it is determined that the radiator water temperature Tr detected by the radiator outlet water temperature sensor 64 does not exceed the radiator water temperature Trth (NO in step S207), the control unit 110 performs the processing of steps S208 to S211 following step S207. The process proceeds to step S212 without executing it.

  On the other hand, when it is determined that the radiator water temperature Tr detected by the radiator outlet water temperature sensor 64 has exceeded the radiator water temperature Trth (YES in step S207), the control unit 110 controls the drive motor 61a to control the electric water pump 61. Is driven (step S208). Therefore, the cooling water is circulated in the intake air cooling unit 60.

Next, the control unit 110 determines whether or not the exhaust gas recirculation by the EGR device 130 is stopped (step S209). Specifically, the control unit 110 determines whether or not the exhaust gas recirculation by the EGR device 130 is stopped by determining whether or not the engine water temperature Te is equal to or lower than the engine water temperature Teth ₂ . When it is determined that exhaust gas recirculation by EGR device 130 has not stopped (NO in step S209), control unit 110 repeatedly executes step S209 until it is determined that exhaust gas recirculation has been stopped. .

On the other hand, when it is determined by the control unit 110 that exhaust gas recirculation by the EGR device 130 has stopped (YES in step S209), the control unit 110 performs predetermined processing after the exhaust gas recirculation by the EGR device 130 has stopped. It determines whether the time _{t 1} has elapsed (step S210). Control unit 110 repeats the processing of step S210 until it determines that the predetermined time t ₁ of the above has elapsed. On the other hand, the control unit 110, after the recirculation of exhaust gas by the EGR device 110 is stopped, when it is determined that the predetermined time _{t 1} has elapsed controls to stop driving the (YES at step S210), the driving motor 61a Then, the circulation of the cooling water in the intake air cooling unit 160 is stopped by stopping the electric water pump 61 (step S211).

Next, the control unit 110 determines whether or not the engine 102 has been stopped by grasping the states of the ignition device and the fuel injection device (step S212). When it is determined that the engine 102 is not stopped (NO in step S212), the control unit 110 returns to step S205, and executes the processes in steps S205 to S212 again.
On the other hand, if it is determined that engine 102 has stopped (YES in step S212), control unit 110 ends this process.

  Since engine cooling device 140 according to the present embodiment is configured as described above, the following effects can be obtained.

  When the radiator water temperature Tr detected by the radiator outlet water temperature sensor 64 and the control unit 110 exceeds the radiator water temperature Trth, the control unit 110 controls the electric water pump 61 to circulate the cooling water in the intake air cooling unit 160. For example, during normal driving in an urban area or the like after completion of warm-up of the engine 102, the exhaust gas recirculated by the EGR device 130 can be cooled by using the surplus cooling capacity of the engine cooling device 140. In addition, the intake air including the exhaust gas recirculated that is sucked into the engine 102 is further cooled by the intake water cooling spacer 62. For this reason, during normal traveling, the temperature rise in the combustion chamber 102d of the engine 102 can be suppressed by utilizing the excess cooling capacity, and the occurrence of knocking due to the temperature rise in the combustion chamber 102d can be prevented. can do.

On the other hand, after the control unit 110 determines that the exhaust gas recirculation by the EGR device 130 has stopped, the control unit 110 controls the electric water pump 61 to stop the circulation of the cooling water in the intake air cooling unit 160. Therefore, for example, in the case of uphill traveling where the load applied to the engine 102 increases compared with that during normal traveling, cooling of each cylinder of the engine 102 that is originally required is performed with priority over cooling of the intake air. be able to. In addition, since the circulation of the cooling water in the intake air cooling unit 160 is stopped when the predetermined time t ₁ has elapsed after the recirculation of the exhaust gas by the EGR device 130 is stopped, the overheating of the intake air cooling unit 160 is performed. Can be suppressed.

(Third embodiment)
A hybrid vehicle 200 to which an engine cooling apparatus 240 according to a third embodiment of the present invention is applied will be described with reference to FIGS. 1, 12, and 13.

  In the engine cooling device 240 for the hybrid vehicle 200 according to the third embodiment of the present invention, the intake water cooling spacer 62 is different from the engine cooling device 40 for the hybrid vehicle 1 according to the first embodiment of the present invention. Instead, an EGR device 135 is provided and a radiator outlet water temperature sensor 64 is not provided. The cooling device for an engine 140 of the hybrid vehicle 100 according to the second embodiment of the present invention and the radiator are different from the cooling device 140 for an engine. Although different in that the outlet water temperature sensor 64 is not provided, other configurations are configured similarly. Therefore, the same configuration will be described using the same reference numerals as those in the first and second embodiments shown in FIGS. 1 to 11, and only differences will be described in detail.

  As shown in FIG. 1, hybrid vehicle 200 includes an engine 102 as an internal combustion engine, motor generator MG1 and motor generator MG2 as rotating electrical machines, power split device 4, differential gear 5, gear 6 and gear 7. A battery B, a boosting unit 8, an inverter 9, a control unit 210, front wheels 12R and 12L, rear wheels 13R and 13L, a radiator 15 for electrical equipment, and a cooling device 220 including a radiator 16 for an engine. It is configured to include.

  The control unit 210 is responsive to the driver's instructions and outputs from various sensors provided in the hybrid vehicle 200, the engine 102, the inverter 9, the boost unit 8, the system main relays 8a and 8b, the cooling device 220, and the EGR device 130. Control is to be performed. Therefore, the control unit 210 constitutes the hybrid vehicle 200 and also constitutes the cooling device 220 and the EGR device 130.

  The cooling device 220 includes an electric device cooling device 30 including the electric device radiator 15, and an engine cooling device 240 including the engine radiator 16 and the EGR cooler 135.

  The engine cooling device 240 is provided separately from the electric device cooling device 30 and includes the engine radiator 16, the EGR cooler 135, the engine water pump 52, and the like. The engine cooling device 240 configured as described above includes an engine cooling water passage 54 and a bypass passage that constitute a part of the cooling water passage 240 a by the engine water pump 52 between the engine radiator 16 and the engine 102. Cooling water as a refrigerant discharged from the engine radiator 16 is circulated through the heater core cooling water passage 58 and the heater core 56. That is, the engine cooling device 240 is configured so that the cooling water circulating in the cooling water passage 240a takes heat generated by the engine 102 and dissipates heat to the outside air by the engine radiator 16, thereby cooling the engine 102 described above. It has become. Engine cooling device 240 according to the present embodiment constitutes a cooling device according to the present invention.

Next, an engine cooling device 240 according to a third embodiment of the present invention will be described in detail with reference to FIG.
As shown in FIG. 12, the engine cooling device 240 includes an engine cooling unit 50, an exhaust cooling unit 260, an engine radiator 16 shared by the engine cooling unit 50 and the exhaust cooling unit 260, and an engine outlet water temperature sensor. 65 and the control part 210 are comprised. Exhaust cooling unit 260 of engine cooling device 240 according to the present embodiment constitutes a third cooling unit in the cooling device according to the present invention.

The exhaust cooling unit 260 is provided independently of the engine cooling unit 50 described above, and includes an electric water pump 61 and an EGR cooler 135. The exhaust cooling unit 260 is connected to the electric water pump 61 and the EGR cooler 135 and the engine radiator 16 via the EGR cooling water passage 266 that constitutes a part of the cooling water passage 240a (see FIG. 1). Cooling water is circulated. In other words, the exhaust cooling unit 260 cools the exhaust gas in which the cooling water circulated through the EGR cooling water passage 266 is recirculated by the EGR device 130.
Here, the EGR cooling water passage 266 branches from the engine cooling water passage 54a, and the flow passage 266a through which the cooling water flowing from the radiator outlet 16a to the electric water pump 61 circulates, and the electric water pump 61 to EGR. The flow path 266b flows through the cooling water flowing through the cooler 135, and the flow path 266c flows through the cooling water flowing from the EGR cooler 135 to the radiator inlet 16b. The EGR coolant passage 266 of the engine cooling device 240 according to the present embodiment constitutes a third circulation channel according to the present invention.

  The EGR cooler 135 is provided in the EGR cooling water passage 266 between the electric water pump 61 and the radiator inlet 16b, and the cooling water is circulated from the engine radiator 16 via the electric water pump 61. Yes. Thereby, the EGR cooler 135 cools the exhaust gas recirculated through the EGR passage 131a toward the intake passage 104 with the circulating coolant.

The controller 210 determines whether or not the engine coolant temperature Te exceeds the engine coolant temperature Teth ₂ that has been experimentally obtained and stored in advance. When it is determined that the exhaust gas can be recirculated by the EGR device 130, that is, when it is determined that the engine water temperature Te exceeds the engine water temperature Teth ₂ , the control unit 210 controls the drive motor 61a to control the electric water pump. 61 is driven to circulate the cooling water in the exhaust cooling unit 260. The electric water pump 61 in the engine cooling device 240 according to the present embodiment constitutes the refrigerant circulation means according to the present invention, and the control unit 210 constitutes the control means. Further, the engine water temperature Teth ₂ described above in the engine cooling device 240 according to the present embodiment corresponds to the third threshold value.

  Next, the EGR cooling control executed in the engine cooling apparatus 240 according to the third embodiment of the present invention will be described with reference to FIG.

  The flowchart shown in FIG. 13 shows the execution contents of the processing program for the EGR cooling control stored in the ROM of the control unit 210, and this processing program includes a single program or a plurality of programs for executing the control contents. Has been. The processing program for EGR cooling control is executed by the CPU of the control unit 210 at predetermined time intervals.

  As shown in FIG. 13, the control unit 210 determines whether or not the engine 102 has been started by grasping the states of the ignition device and the fuel injection device (step S301).

  If it is determined by the control unit 210 that the engine 102 has been started (YES in step S301), the control unit 210 determines whether warm-up is necessary (step S302). Specifically, the control unit 210 determines whether or not the engine 102 needs to be warmed up, such as warming up of the intake port 102b, based on the engine water temperature Te and whether or not the catalyst of the exhaust purification device needs to be warmed up. Is determined based on the catalyst temperature. If controller 210 determines that warming up of engine 102 and warming up of the catalyst are necessary (YES in step S302), control unit 210 warms up engine 102 and warms up the catalyst (step S303). On the other hand, when it is determined that engine 102 has not been started (NO in step S301), control unit 210 repeats the process of step S301 again.

  Next, the control unit 210 determines whether or not the warming up of the engine 102 and the warming up of the catalyst executed in step S303 have been completed (step S304). Specifically, the control unit 210 determines whether or not the estimated wall temperature estimated from the engine water temperature Te of the cylinder head 102d surrounding the intake port 102b of the engine 102 has reached a predetermined temperature based on the engine water temperature Te described above. By doing so, it is determined whether or not the engine 102 has been warmed up. Further, the controller 210 determines whether the catalyst temperature is equal to or higher than the activation temperature of the catalyst, or whether a predetermined time after which the catalyst temperature has reached the activation temperature has elapsed after the engine 102 is started. Determine whether the warm-up is complete.

  When it is determined that the engine 102 has been warmed up and the catalyst has been warmed up (YES in step S304), control unit 210 proceeds to step S305. When controller 210 determines that engine 102 has not been warmed up and catalyst has not been warmed up (NO in step S304), it is determined that engine 102 has been warmed up and catalyst has been warmed up. Step S304 is repeated.

On the other hand, when it is determined in step S302 that the engine 102 is not warmed up and the catalyst is not warmed up (NO in step S302), the control unit 210 executes the processes in steps S303 and S304 described above. Instead, the process proceeds to step S305.
Next, the engine outlet water temperature sensor 65 and the controller 210 detect the engine water temperature Te (step S305).

Next, the controller 210 determines whether or not the engine coolant temperature Te has exceeded the engine coolant temperature Teth ₂ (step S306). In other words, the control unit 210 determines whether or not the exhaust gas recirculation by the EGR device 130 is possible. When controller 210 determines that exhaust gas recirculation by EGR device 130 is not possible (NO in step S306), that is, when it is determined that engine coolant temperature Te does not exceed engine coolant temperature Teth ₂ , engine coolant temperature Te. Until the engine temperature exceeds the engine water temperature Teth ₂ , the processes in steps S305 and S306 are repeated. On the other hand, when controller 210 determines that exhaust gas recirculation by EGR device 110 is possible, that is, when it is determined that engine coolant temperature Te exceeds engine coolant temperature Teth ₂ (YES in step S306), drive motor 61a. Is controlled to drive the electric water pump 61 (step S307). Therefore, the cooling water is circulated in the exhaust cooling unit 260.

Next, the controller 210 determines whether or not the exhaust gas recirculation by the EGR device 130 is stopped (step S308). Specifically, the control unit 210 determines whether or not the exhaust gas recirculation by the EGR device 130 is stopped by determining whether or not the engine water temperature Te is equal to or lower than the engine water temperature Teth ₂ . When it is determined that the exhaust gas recirculation by the EGR device 130 is not stopped (NO in step S308), the control unit 210 repeatedly executes the process of step S308 until it is determined that the exhaust gas recirculation is stopped. .

On the other hand, when it is determined by the control unit 210 that exhaust gas recirculation by the EGR device 130 has stopped (YES in step S308), the control unit 210 performs a predetermined process after the exhaust gas recirculation by the EGR device 130 has stopped. It determines whether the time _{t 1} has elapsed (step S309). Control unit 210 repeats the processing of step S309 until it determines that the predetermined time t ₁ of the above has elapsed. On the other hand, the control unit 210, after the recirculation of exhaust gas by the EGR device 130 is stopped, when it is determined that the predetermined time _{t 1} has elapsed controls to stop driving the (YES in step S309), the driving motor 61a By stopping the electric water pump 61, the circulation of the cooling water in the exhaust cooling unit 260 is stopped (step S310).

Next, the control unit 210 determines whether or not the engine 102 has been stopped by grasping the states of the ignition device and the fuel injection device (step S311). When it is determined that the engine 102 has not stopped (NO in step S311), the control unit 210 returns to step S305 and executes the processes of steps S305 to S311 again.
On the other hand, when it is determined that the engine 102 has stopped (YES in step S311), the control unit 210 ends this process.

  Since engine cooling device 240 according to the present embodiment is configured as described above, the following effects can be obtained.

When the engine water temperature Te detected by the engine outlet water temperature sensor 65 and the control unit 210 exceeds the engine water temperature Teth ₂ , the control unit 210 controls the electric water pump 61 to circulate the cooling water in the exhaust cooling unit 260. For example, during normal travel in an urban area or the like after completion of warming up of the engine 102, the exhaust gas recirculated by the EGR device 130 can be cooled by using the surplus of the cooling capacity of the engine cooling device 240. As a result, the intake air including the exhaust gas recirculated and sucked into the engine 102 is cooled. For this reason, during normal traveling, the temperature rise in the combustion chamber 102d of the engine 102 can be suppressed by utilizing the excess cooling capacity, and the occurrence of knocking due to the temperature rise in the combustion chamber 102d can be prevented. can do.

On the other hand, after the control unit 210 determines that the exhaust gas recirculation by the EGR device 130 has stopped, the control unit 210 controls the electric water pump 61 to stop the circulation of the cooling water in the exhaust cooling unit 260. Therefore, for example, in the case of uphill traveling where the load applied to the engine 102 increases compared with that during normal traveling, cooling of each cylinder of the engine 102 that is originally required is performed with priority over cooling of the intake air. be able to. In addition, since the circulation of the cooling water in the exhaust cooling unit 260 is stopped when the predetermined time t ₁ has elapsed after the exhaust gas recirculation by the EGR device 130 is stopped, the exhaust cooling unit 260 is overheated. Can be suppressed.

  In addition, the embodiment disclosed this time is illustrative in all respects and is not limited to this embodiment. The scope of the present invention is shown not by the above description of the embodiments but by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

  As described above, the cooling device according to the present invention knocks due to the temperature rise in the combustion chamber of the internal combustion engine during normal traveling or the like by using the surplus cooling capacity without impairing the cooling effect of the internal combustion engine. It has the effect of being able to prevent efficiently, and is useful for the cooling device for hybrid vehicles for internal combustion engines provided independently of the cooling device for electric motors.

1, 100, 200 Hybrid vehicle 2, 102 Engine (internal combustion engine)
10, 110, 210 Control unit (first refrigerant temperature detection means, second refrigerant temperature detection means, control means, EGR stop determination means)
16 Engine radiator (heat exchanger)
40, 140, 240 Engine cooling device (cooling device)
50 Engine cooling part (first cooling part)
54 Cooling water passage for engine (first circulation passage)
60, 160 Intake air cooling part (second cooling part)
61 Electric water pump (refrigerant circulation means)
62 Intake water cooling spacer 64 Radiator outlet water temperature sensor (first refrigerant temperature detection means)
65 Engine outlet water temperature sensor (second refrigerant temperature detecting means)
66, 166 Intake cooling water passage (second circulation passage)
130 EGR device 135 EGR cooler (EGR cooling part)
260 Exhaust cooling part (third cooling part)
266 EGR cooling water passage (third circulation passage)
MG1, MG2 Motor generator (rotary electric machine)

Claims (2)

A cooling device that includes an internal combustion engine and a rotating electric machine, and that is applied to a hybrid vehicle that uses at least one of the internal combustion engine and the rotating electric machine as a travel source,
A heat exchanger that exchanges heat between the refrigerant and the outside air;
A first cooling section formed with a first circulation flow path for circulating the refrigerant discharged from the heat exchanger to cool the internal combustion engine;
A second circulation channel is formed which branches from the first circulation channel and circulates the refrigerant discharged from the heat exchanger to cool the intake air supplied to the internal combustion engine. The cooling section of
A refrigerant circulation means provided on the second circulation channel and forcibly circulating the refrigerant;
First refrigerant temperature detection means for detecting the temperature of the refrigerant discharged from the heat exchanger;
Second refrigerant temperature detection means for detecting the temperature of the refrigerant after cooling the internal combustion engine;
While controlling the refrigerant circulation means to circulate the refrigerant when the temperature of the refrigerant detected by the first refrigerant temperature detection means exceeds a predetermined first threshold, the second refrigerant Control means for controlling the refrigerant circulation means to stop the circulation of the refrigerant when the temperature of the refrigerant detected by the temperature detection means exceeds a second threshold value that is larger than the first threshold value. A cooling device characterized by that. The exhaust gas, which is provided on the second circulation channel and is recirculated by an EGR device that recirculates a part of the exhaust gas discharged from the internal combustion engine to the intake passage of the internal combustion engine, circulates in the second circulation channel. An EGR cooling section cooled by the refrigerant,
EGR stop determination means for determining whether or not the exhaust gas recirculation by the EGR device has stopped,
The control means controls the refrigerant circulation means to circulate the refrigerant when the temperature of the refrigerant detected by the first refrigerant temperature detection means exceeds the first threshold, while stopping the EGR The refrigerant circulation is performed so that the circulation of the refrigerant is stopped when a predetermined time elapses after it is determined by the determination means that the recirculation of the exhaust gas by the EGR apparatus has stopped and the recirculation of the exhaust gas by the EGR apparatus has stopped. 2. The cooling apparatus according to claim 1, wherein the means is controlled.

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