JP4770329B2 - Hybrid vehicle cooling system - Google Patents

Description

  The present invention relates to a cooling device for a hybrid vehicle.

  The hybrid vehicle may include a cooling water passage for cooling the internal combustion engine and a cooling water passage for cooling the motor. The internal combustion engine itself is designed to be in an optimal combustion state when the coolant temperature is approximately 80 ° C. However, if the motor is cooled to such a temperature, the electric circuit of the motor may be hindered. Therefore, the motor is cooled without using the cooling water of the internal combustion engine, and is cooled to, for example, 60 ° C. or less.

As described above, the internal combustion engine and the motor are different from each other in the appropriate temperature of the cooling water. Therefore, a technique is known in which the cooling water passages are provided and the control is performed so as to achieve the appropriate temperatures (for example, Patent Document 1). reference.).
JP 2000-73763 A JP 2004-76603 A

  Among the members attached to the internal combustion engine, in which the cooling water of the internal combustion engine circulates, it may be possible to use the member more effectively by circulating the cooling water at a lower temperature. .

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a technology capable of bringing the temperature of a member closer to the temperature required by the member in a cooling device for a hybrid vehicle. .

  In order to achieve the above object, the hybrid vehicle cooling apparatus according to the present invention employs the following means.

That is,
A cooling device for a hybrid vehicle including an internal combustion engine and a motor,
A first cooling device that cools the internal combustion engine with a temperature of a heat medium that exchanges heat with the internal combustion engine as a first predetermined range;
A second cooling device that cools the motor with a temperature of a heat medium that exchanges heat with the motor as a second predetermined range;
With
Among the members constituting the internal combustion engine or the members attached to the internal combustion engine, the member whose required temperature is lower than the first predetermined range is the heat medium and heat that have been set to the second predetermined range by the second cooling device. It is characterized by exchanging.

  Here, the “required temperature” means an appropriate temperature of the member, a temperature at which the member can be used effectively, or an appropriate operating state of the internal combustion engine when the member reaches the temperature. It is good also as the temperature which can carry out.

The first cooling device cools the internal combustion engine so that the temperature of the internal combustion engine becomes a required temperature of the internal combustion engine. The second cooling device cools the motor so that the temperature of the motor becomes the required temperature of the motor. Therefore, the temperature of the heat medium set by the first cooling device is higher than that of the second cooling device. Here, the member attached to the internal combustion engine has been cooled or heated by heat exchange with the heat medium conventionally set to the first predetermined range by the first cooling device. However, among these members, the required temperature may be lower than the first predetermined range. By cooling or heating such a member with a heat medium having a temperature in the second predetermined range, the temperature of the member can be further reduced, and the temperature of the member can be brought close to the required temperature.

  The cooling device for a hybrid vehicle according to the present invention can bring the temperature of the member closer to the temperature required by the member.

  Hereinafter, specific embodiments of a cooling device for a hybrid vehicle according to the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram illustrating a schematic configuration of an internal combustion engine 1 to which a cooling device for a hybrid vehicle according to the present embodiment is applied.

  The internal combustion engine 1 includes a cylinder head 2 and a cylinder block 3.

  A water jacket 4 for circulating cooling water is formed inside the internal combustion engine 1. The internal combustion engine 1 is connected to a passage for circulating cooling water. The passage for circulating the cooling water includes a first circulation passage 6 that circulates through the radiator 5, a second circulation passage 8 that circulates through the heater core 7, and a third circulation passage 10 that circulates through the bypass passage 9. Yes. A part of each circulation passage has a portion shared with other circulation passages. For example, the water jacket 4 is included in all circulation passages.

  The first circulation passage 6 includes a radiator 5, a thermostat 11, an electric pump 12, and a water jacket 4. The thermostat 11 causes the cooling water to flow through the first circulation passage 6 when the cooling water temperature is high, and causes the cooling water to flow through the third circulation passage 10 when the cooling water temperature is low.

  In the first circulation passage 6, the cooling water discharged from the electric pump 12 flows in the order of the water jacket 4, the radiator 5, and the thermostat 11.

  The second circulation passage 8 includes a heater core 7, an electric pump 12, and a water jacket 4.

  In the second circulation passage 8, the cooling water discharged from the electric pump 12 flows in the order of the water jacket 4 and the heater core 7.

  The third circulation passage 10 includes a bypass passage 9, a thermostat 11, an electric pump 12, and a water jacket 4.

  In the third circulation passage 10, the cooling water discharged from the electric pump 12 flows in the order of the water jacket 4, the bypass passage 9, and the thermostat 11.

The first cooling device 100 is configured by the first circulation passage 6, the second circulation passage 8, and the third circulation passage 10 described above.

  Further, the hybrid vehicle according to the present embodiment includes a motor 30 and an inverter 31.

  The motor 30 drives wheels instead of the internal combustion engine 1. Further, the motor 30 can assist the output of the internal combustion engine 1 as necessary during normal operation. The motor 30 is connected to the battery via the inverter 31.

  In the hybrid vehicle configured as described above, the wheels are driven by the output of the internal combustion engine 1 or the output of the motor 30. Further, the wheels can be driven by combining the output of the internal combustion engine 1 and the output of the motor 30.

  The motor 30 and the inverter 31 are connected to a fourth circulation passage 32 for circulating the cooling water. The fourth circulation passage 32 is provided with an electric pump 33 and a radiator 34. A second cooling device 200 is configured by the fourth circulation passage 32.

  Further, the electric throttle 50 is connected in the middle of the fourth circulation passage 32, and the electric throttle 50 is cooled by the second cooling device 200. In the present embodiment, the electric throttle 50 corresponds to “a member having a required temperature lower than the first predetermined range among members constituting the internal combustion engine or members attached to the internal combustion engine” according to the present invention. .

  Here, the electric throttle 50 is provided in the intake passage of the internal combustion engine 1 and adjusts the flow rate of air flowing through the intake passage. Since the volume of the air expands when the air passes through the electric throttle 50, the temperature of the air is lowered and the electric throttle 50 may be frozen. Therefore, conventionally, the electric throttle 50 is warmed by circulating the cooling water of the internal combustion engine 1.

  However, since the temperature of the cooling water of the internal combustion engine 1 is, for example, 80 ° C. or higher, the temperature of the electric throttle 50 is increased accordingly, and the temperature of the air passing through the electric throttle 50 is increased. As a result, the air density is decreased, the output of the internal combustion engine 1 is decreased, and knocking may occur due to the intake air temperature becoming higher.

  In this regard, in this embodiment, the electric throttle 50 is cooled by the second cooling device 200. In the second cooling device 200, since the required temperature of the motor 30 and the inverter 31 is lower than that of the internal combustion engine 1, the temperature of the cooling water is lower than that of the first cooling device 100, and is designed and controlled to be, for example, 60 ° C. or less. ing.

  Therefore, the temperature of the electric throttle 50 can be made lower than that connected to the first cooling device 100. As a result, the amount of intake air can be increased, and the intake air temperature can be lowered. Therefore, the output of the internal combustion engine can be improved, and the fuel consumption can be improved.

  FIG. 2 is a diagram illustrating a schematic configuration of the internal combustion engine 1 to which the hybrid vehicle cooling device according to the present embodiment is applied.

In the present embodiment, the EGR cooler 51 is connected in the middle of the fourth circulation passage 32, and the EGR cooler 51 is cooled by the second cooling device 200. In this embodiment, the electric throttle 50 is connected to the second circulation passage 8 and cooled by the first cooling device 100. However, the electric throttle 50 is also cooled by the second cooling device 200 as in the first embodiment. It may be.

  The EGR cooler 51 is provided to reduce the temperature of the EGR gas supplied to the intake passage of the internal combustion engine 1. In the EGR cooler 51, heat exchange is performed between the EGR gas and the cooling water, and the temperature of the EGR gas is lowered. In the present embodiment, the EGR cooler 51 corresponds to “a member having a required temperature lower than the first predetermined range among members constituting the internal combustion engine or members attached to the internal combustion engine” according to the present invention. .

  Conventionally, the cooling water of the internal combustion engine 1 is circulated through the EGR cooler 51 to reduce the temperature of the EGR gas. However, if the temperature of the EGR gas is not sufficiently lowered, the intake air temperature becomes high and knocking may occur. In addition, it is conceivable to suppress the occurrence of knocking by lowering the temperature in the cylinder by increasing the supply fuel, but this causes a deterioration in fuel consumption.

  In that respect, in the present embodiment, the EGR cooler 51 is connected to the second cooling device 200. Thereby, the temperature of the cooling water for heat exchange with the EGR gas becomes lower than that connected to the first cooling device 100, and the temperature of the EGR gas can be made lower.

  Therefore, the intake air temperature can be lowered and the occurrence of knocking can be suppressed. Moreover, since it is not necessary to increase the fuel supply amount, the fuel consumption can be improved. Furthermore, since the combustion temperature is lowered, the cooling loss in the internal combustion engine 1 can be reduced, and the fuel consumption can be improved.

  In this embodiment, the intercooler may be cooled by the second cooling device 200 in place of the EGR cooler 51 or together with the EGR cooler 51.

  Here, since the temperature of the air rises when the air is compressed by the turbocharger, the temperature of the air is lowered by the intercooler. And by cooling the intercooler by the second cooling device 200, the temperature sucked into the internal combustion engine 1 can be further lowered. Therefore, the occurrence of knocking can be suppressed. Further, fuel efficiency can be improved in the same manner as in the case of EGR gas.

  FIG. 3 is a diagram illustrating a schematic configuration of the internal combustion engine 1 to which the hybrid vehicle cooling device according to the present embodiment is applied.

  Compared to the first embodiment, the fourth circulation passage 32 is different in that it passes through the inside of the cylinder head 2. In FIG. 3, the fourth circulation passage 32 is indicated by a broken line.

  Here, the fourth circulation passage 32 is not connected to the circulation passage constituting the first cooling device 100 as in the above-described embodiment. That is, the cooling water of the 1st cooling device 100 and the 2nd cooling device 200 does not mix. In this embodiment, the electric throttle 50 is connected to the second circulation passage 8 and cooled by the first cooling device 100. However, the electric throttle 50 is also cooled by the second cooling device 200 as in the first embodiment. It may be. The fourth circulation passage 32 is arranged so as to pass near the intake port of each cylinder, for example. In the present embodiment, the cylinder head 2 in the vicinity of the intake port is a member having a required temperature lower than the first predetermined range among the members constituting the internal combustion engine or the members attached to the internal combustion engine according to the present invention. Is equivalent to.

  Here, by cooling the vicinity of the intake port by the second cooling device 200, the temperature in the intake port can be made lower than when cooling by the first cooling device 100.

  Therefore, since the temperature of the air passing through the intake port can be lowered, the intake air temperature can be lowered and the occurrence of knocking can be suppressed. Further, since it is not necessary to increase the fuel supply amount in order to suppress the occurrence of knocking, the fuel consumption can be improved. Furthermore, since the air density increases due to a decrease in the intake air temperature, the intake air amount can be increased and the engine output can be increased.

  On the other hand, when the fourth circulation passage 32 is arranged so as to pass, for example, near the exhaust port of each cylinder, the exhaust temperature can be lowered as compared with the case where the first cooling device 100 cools the exhaust port. it can.

  As a result, the exhaust density can be reduced, and the exhaust is easily discharged from the cylinder. Therefore, the occurrence of knocking due to the residual gas in the cylinder can be suppressed. Further, the fuel supply amount can be reduced, and the fuel consumption can be improved.

1 is a diagram illustrating a schematic configuration of an internal combustion engine to which a hybrid vehicle cooling device according to a first embodiment is applied. FIG. It is a figure which shows schematic structure of the internal combustion engine to which the cooling device of the hybrid vehicle which concerns on Example 2 is applied. FIG. 6 is a diagram illustrating a schematic configuration of an internal combustion engine to which a hybrid vehicle cooling device according to a third embodiment is applied.

Explanation of symbols

1 Internal combustion engine 2 Cylinder head 3 Cylinder block 4 Water jacket 5 Radiator 6 First circulation passage 7 Heater core 8 Second circulation passage 9 Bypass passage 10 Third circulation passage 11 Thermostat 12 Electric pump 30 Motor 31 Inverter 32 Fourth circulation passage 33 Electric Pump 34 Radiator 50 Electric throttle 51 EGR cooler and / or intercooler 100 First cooling device 200 Second cooling device

Claims (1)

A cooling device for a hybrid vehicle including an internal combustion engine and a motor,
A first cooling device that cools the internal combustion engine with a temperature of a heat medium that exchanges heat with the internal combustion engine as a first predetermined range;
A second cooling device that cools the motor with a temperature of a heat medium that exchanges heat with the motor as a second predetermined range;
An electric throttle provided in the intake passage of the internal combustion engine;
With
The electric throttle, which is a member having a required temperature lower than the first predetermined range among members constituting the internal combustion engine or members attached to the internal combustion engine, is set to a temperature in the second predetermined range by the second cooling device. A cooling device for a hybrid vehicle, characterized by performing heat exchange with a heat medium.

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