JP7371542B2 - hybrid vehicle - Google Patents

Description

The present invention provides a hybrid vehicle that is equipped with an engine and a motor as a drive source for driving, and performs engine-operated driving, in which the engine is running, and electric driving, in which the engine is stopped and the vehicle is powered by the motor. Regarding.

As a hybrid vehicle as described above, a vehicle described in Patent Document 1 is known. The hybrid vehicle described in this document is equipped with an air conditioner that heats the interior of the vehicle using engine exhaust heat as a heat source. In this hybrid vehicle, a heat source for heating cannot be obtained while the engine is stopped, so if heating is requested during electric driving, the engine is operated to perform engine-operated driving.

Japanese Patent Application Publication No. 2007-230385

Note that in order to be able to perform heating even when the engine is stopped during electric driving, it is conceivable to mount a heating device on a hybrid vehicle that uses a heat pump system that recovers heat for heating from the outside air. In such a case, interruptions in electric driving for heating can be eliminated, and fuel consumption can be reduced accordingly.

Furthermore, heat pump systems can be used not only for heating, but also for purposes such as dehumidifying vehicle interiors and cooling in-vehicle equipment such as batteries. However, due to the structure of the heat pump system, it may not be possible to perform heating, dehumidification, and cooling of in-vehicle equipment at the same time, and if these are required to be performed simultaneously during electric driving, the engine may have to be operated. There is.

A hybrid vehicle that solves the above problems includes a heat pump system that recovers heat from outside air to heat a vehicle interior, and an air conditioning control unit that controls the heat pump system. The heat pump system in the hybrid vehicle consists of a compressor that compresses refrigerant and a unit that heats the air that is blown into the vehicle interior. A heater unit that can be used as a heat source, an outdoor heat exchanger that exchanges heat between the refrigerant and the outside air, an air conditioning evaporator that uses the heat of vaporization of the refrigerant to cool the air that flows into the heater unit, and an in-vehicle device that uses the heat of vaporization of the refrigerant to cool the air that flows into the heater unit. A mechanism for distributing refrigerant passed through a heater unit to an air conditioning evaporator and an evaporator for onboard equipment, the refrigerant distribution mechanism adjusting a distribution ratio of refrigerant between the two evaporators. There is. The heat pump system dehumidifies and heats the vehicle interior by cooling the air using an air conditioning evaporator and heating the air using a heater unit. The air conditioning control unit in the hybrid vehicle also includes an operation process for operating a refrigerant distribution mechanism to cool the on-vehicle equipment by the on-vehicle equipment evaporator when the temperature of the on-board equipment is equal to or higher than the cooling start temperature, and a second heat source. If cooling of the on-vehicle equipment and dehumidifying/heating are requested to be performed simultaneously when the second heat source is in a state where it has stopped generating heat, a heat source state switching process is performed to switch the state of the second heat source to a state where it generates heat, and the dehumidifying/heating is performed. Determine whether or not there is a high possibility of implementing dehumidifying heating, and if it is determined that there is a high possibility of implementing dehumidifying heating, if it is determined that the same possibility is not high. A setting process of setting a temperature higher than the value of the cooling start temperature is performed.

In the above hybrid vehicle, during dehumidification heating when the second heat source stops generating heat, the refrigerant used as a heat source for air heating in the heater unit flows into the refrigerant distribution mechanism after being compressed by the compressor. Depending on the amount of heat consumed in heating the air in the heater unit at this time, the refrigerant flowing into the refrigerant distribution mechanism becomes a gas-liquid mixture, and the refrigerant distribution mechanism accurately adjusts the distribution ratio of refrigerant between the air conditioning evaporator and the on-vehicle equipment evaporator. It may become impossible to make adjustments. Therefore, in the above-mentioned hybrid vehicle, when simultaneous implementation with dehumidifying heating is requested while the second heat source is in a state where it has stopped generating heat, by switching the state of the second heat source to a state where it is generating heat, This makes it possible to cool in-vehicle equipment and dehumidify and heat at the same time. Note that the energy required to drive actuators other than the compressor in the heat pump system, such as the refrigerant distribution mechanism, is smaller than the energy required to drive the compressor, so dehumidifying and heating cannot be performed when the second heat source has stopped generating heat. Most of the energy consumed is required to drive the compressor. On the other hand, even when the second heat source generates heat and performs dehumidifying heating, it is necessary to drive the compressor in order to cool the air with the air conditioning evaporator. Therefore, in this case, the efficiency of dehumidifying and heating becomes worse due to the energy required to generate heat from the second heat source.

On the other hand, in the above-mentioned hybrid vehicle, when it is determined that there is a high possibility that dehumidification and heating will be performed, the value of the cooling start temperature, which is the threshold value of the temperature of the on-board equipment at which cooling of the on-board equipment starts, is set to The temperature is set higher than when it is determined that the possibility of the same is low. Therefore, when there is a high possibility that dehumidifying and heating will be performed, cooling of the on-vehicle equipment will start later when the temperature of the on-vehicle equipment increases than when the possibility is low. Therefore, by simultaneously performing dehumidifying heating and cooling of the on-vehicle equipment, the state in which the second heat source stops generating heat becomes less likely to be interrupted. Therefore, according to the above-mentioned hybrid vehicle, energy consumption for dehumidifying and heating the vehicle interior and cooling the vehicle-mounted equipment can be suppressed.

FIG. 1 is a diagram schematically showing the configuration of a heat pump system and a heater water circuit included in an embodiment of a hybrid vehicle. FIG. 2 is a diagram schematically showing the configuration of a control system of the hybrid vehicle. 1 is a flowchart of a battery control routine executed by an air conditioning control unit in the hybrid vehicle.

Hereinafter, one embodiment of a hybrid vehicle will be described in detail with reference to FIGS. 1 to 3.
As shown in FIG. 1, the hybrid vehicle of this embodiment includes, as a driving source for running, an engine 10 that generates power by burning fuel, and a motor 11 that generates power by receiving power from a battery 12. ing. The hybrid vehicle is capable of engine-operated driving, in which the vehicle travels with the engine 10 running, and electric driving, in which the hybrid vehicle travels with the power of the motor 11 while the engine 10 is stopped.

Hybrid vehicles are equipped with an air conditioning system for air conditioning the interior of the vehicle. The air conditioning system includes an air conditioning case 20 installed in an instrument panel at the forefront of the vehicle interior. Inside the air conditioning case 20, a passage for air to be blown into the vehicle interior is formed. An electric blower 21 that blows air is installed inside the air conditioning case 20. An air-conditioning evaporator 22 is installed inside the air-conditioning case 20 on the downstream side of the air flow from the blower 21 to cool the air using the heat of vaporization accompanying the expansion of the refrigerant. Furthermore, a heater core 23 that heats the air by heat exchange with engine cooling water flowing inside the air conditioning case 20 is installed in a portion downstream of the blower 21 in the air flow. Additionally, inside the air conditioning case 20, there is a mixture door 24 for adjusting the ratio between the flow rate of air passing through the heater core 23 and the flow rate of air bypassing the heater core 23 after passing through the air conditioning evaporator 22. is installed.

Further, the hybrid vehicle of this embodiment includes a heat pump system 30. The heat pump system 30 includes an electric compressor 31 that compresses and discharges refrigerant, a water-refrigerant heat exchanger 32 that exchanges heat between engine cooling water and the refrigerant, and an outdoor heat exchanger that exchanges heat between the outside air and the refrigerant. It is equipped with 33. The heat pump system 30 also includes the above-described air conditioning evaporator 22 and a battery evaporator 34 for cooling the battery 12. The compressor 31 compresses the refrigerant pumped up from the accumulator tank 35 that stores the refrigerant in a gas-liquid separated state and sends it to the water-refrigerant heat exchanger 32 . A high-pressure refrigerant passage 36 is connected to the refrigerant outlet of the water-refrigerant heat exchanger 32 . The high-pressure refrigerant passage 36 is connected to the outdoor heat exchanger 33 via a high-stage expansion valve 37 that is an electrically operated variable throttle valve whose throttle opening can be changed.

A refrigerant outlet side of the outdoor heat exchanger 33 is connected to a refrigerant distribution mechanism 39 via a low-pressure refrigerant passage 38 . A check valve 40 is installed in the low-pressure refrigerant passage 38 to allow the flow of refrigerant from the outdoor heat exchanger 33 side toward the refrigerant distribution mechanism 39 side, while blocking the flow of refrigerant in the opposite direction. The refrigerant flowing into the refrigerant distribution mechanism 39 from the low-pressure refrigerant passage 38 is distributed in the refrigerant distribution mechanism 39 to the air conditioning evaporator 22 side and the battery evaporator 34 side. The refrigerant distribution mechanism 39 includes two flow rate adjustment valves 39a and 39b that respectively adjust the flow rate of the refrigerant sent to the air conditioning evaporator 22 and the flow rate of the refrigerant sent to the battery evaporator 34.

On the refrigerant inlet side of the air conditioning evaporator 22, a low-stage expansion valve 41, which is an electrically operated variable throttle valve whose throttle opening can be changed, is installed. The refrigerant outlet side of the air conditioning evaporator 22 is connected to an accumulator tank 35 via a constant pressure valve 42. The constant pressure valve 42 is provided to maintain constant refrigerant pressure on the refrigerant outlet side of the air conditioning evaporator 22.

On the other hand, on the refrigerant inlet side of the battery evaporator 34, an expansion valve 43 with a fixed throttle opening is installed. Further, the refrigerant inlet side of the battery evaporator 34 is connected to an accumulator tank 35 via a check valve 44 .

Furthermore, this heat pump system 30 includes a refrigerant passage 45 for directly returning the refrigerant that has passed through the outdoor heat exchanger 33 to the accumulator tank 35, and a refrigerant passage 45 for directly returning the refrigerant that has passed through the water-refrigerant heat exchanger 32 to the refrigerant distribution mechanism 39. A refrigerant passage 46 is provided for this purpose. The refrigerant passage 45 is a passage that communicates between a portion of the low-pressure refrigerant passage 38 upstream of the check valve 40 and the accumulator tank 35 . The refrigerant passage 45 is provided with an electromagnetic on-off valve 47 that allows the refrigerant to flow through the refrigerant passage 45 when the valve is opened, and blocks the flow of the refrigerant when the valve is closed. Further, the refrigerant passage 46 is a passage that communicates between a portion of the high-pressure refrigerant passage 36 upstream of the high-stage expansion valve 37 and a portion of the low-pressure refrigerant passage 38 downstream of the check valve 40 . The refrigerant passage 46 is provided with an electromagnetic on-off valve 48 that allows the refrigerant to flow through the refrigerant passage 46 when the valve is opened, and blocks the flow of the refrigerant when the valve is closed.

Further, the hybrid vehicle of this embodiment is provided with a heater water circuit 50 that is a circulation circuit for cooling water passing through the heater core 23 described above. The heater water circuit 50 is provided with the above-described water/refrigerant heat exchanger 32, electric water pump 51, and three-way valve 52. The three-way valve 52 can switch the heater water circuit 50 into the following three states. That is, a state in which engine cooling water circulates between the engine 10 and the heater core 23, a state in which engine cooling water circulates between the electric water pump 51, the water-coolant heat exchanger 32, and the heater core 23, and a state in which the engine cooling water circulates between the engine 10 and the heater core 23; and a state in which the flow of cooling water is cut off. When engine cooling water is circulated between the heater core 23 and the engine 10 during operation of the engine 10, the engine cooling water, which has become high in temperature due to exhaust heat from the engine 10, flows into the heater core 23. On the other hand, when the compressor 31 and the electric water pump 51 are operated and the engine cooling water is circulated through the electric water pump 51, the water-refrigerant heat exchanger 32, and the heater core 23, the engine cooling water is is heated by the refrigerant that has become high temperature due to compression by the compressor 31. Then, the engine cooling water heated by the water-refrigerant heat exchanger 32 flows into the heater core 23. In this way, the hybrid vehicle of this embodiment includes the heater unit 53 that can use both the refrigerant compressed by the compressor 31 and the engine 10 as a heat source for heating the air blown into the vehicle interior. . The heater unit 53 includes a heater core 23, a water/refrigerant heat exchanger 32, a heater water circuit 50, an electric water pump 51, and a three-way valve 52. In the heater unit 53 configured in this manner, the engine 10 corresponds to a second heat source that is a heat source other than the refrigerant compressed by the compressor 31.

FIG. 2 shows the configuration of the control system of the hybrid vehicle. The hybrid vehicle includes an air conditioning control unit 60. The air conditioning control unit 60 is configured as an electronic control unit that includes an arithmetic processing device 61 that executes various arithmetic processing for air conditioning control, and a storage device 62 that stores control programs and data. The air conditioning control unit 60 executes processing for air conditioning control of the vehicle interior by the arithmetic processing unit 61 reading a program from the storage device 62 and executing the program.

The air conditioning control unit 60 receives detection signals from an outside air temperature sensor 63 that detects the outside air temperature THA and a battery temperature sensor 64 that detects the battery temperature THC. Furthermore, detection signals of the temperature and pressure of the refrigerant in each part of the heat pump system 30 are input to the air conditioning control unit 60 . Further, the air conditioning control unit 60 receives an operation signal, which is a signal indicating the operation status, from an air conditioning operation panel 65 provided on an instrument panel in the vehicle interior. Then, the air conditioning control unit 60 outputs operation signals OS1 to OS7 based on these signals, and outputs operation signals OS1 to OS7 for the compressor 31, the high-stage expansion valve 37, the electromagnetic on-off valves 47 and 48, and both flow rate adjustment valves 39a of the refrigerant distribution mechanism 39. , 39b, and the low-stage expansion valve 41, the flow of refrigerant in the heat pump system 30 is controlled. Further, the air conditioning control unit 60 controls the flow of engine cooling water in the heater water circuit 50 by outputting operation signals OS8 and OS9 to operate the electric water pump 51 and the three-way valve 52, respectively. In addition, the air conditioning control unit 60 controls the amount of air blown by the blower 21 by outputting an operation signal OS10 to operate the blower 21.

Further, the hybrid vehicle is equipped with a travel control unit 66 that is an electronic control unit for travel control. The driving control unit 66 switches between engine-operated driving and electric driving depending on the driving status of the hybrid vehicle, the charging status of the battery 12, a request from the air conditioning control unit 60, and the like. Incidentally, the engine 10 serving as the second heat source is in a state where it generates heat when the vehicle is running with the engine running, and is in a state where it stops generating heat when the vehicle is running on electric power.

Next, the air conditioning control performed by the air conditioning control unit 60 will be described. The air conditioning control unit 60 controls the flow of refrigerant in the heat pump system 30 and the flow of engine cooling water in the heater water circuit 50, thereby performing air conditioning and dehumidification/heating of the passenger compartment.

First, the cooling control performed by the air conditioning control unit 60 to cool the vehicle interior will be described. In the cooling control, the air conditioning control unit 60 stops the electric water pump 51 and operates the three-way valve 52 to block the flow of engine cooling water into the heater core 23 . Further, in cooling control, the air conditioning control unit 60 operates the blower 21 while controlling the heat pump system 30 described below. That is, in cooling control, the air conditioning control unit 60 fully opens the high-stage expansion valve 37 and the flow rate adjustment valve 39a on the side of the air conditioning evaporator 22, and fully opens the electromagnetic on-off valves 47, 48, and the flow rate adjustment valve 39b on the side of the battery evaporator 34. The compressor 31 is operated with the fully closed state and the low-stage expansion valve 41 in a throttled state. In the heat pump system 30 during cooling control, refrigerant flows from the accumulator tank 35 through compression in the compressor 31, cooling in the outdoor heat exchanger 33, expansion in the air conditioning evaporator 22, and then returning to the accumulator tank 35. It is circulated.

Next, a description will be given of dehumidifying and heating control during engine operation, which is performed by the air conditioning control unit 60 to dehumidify and heat the vehicle interior while the engine is running. At this time, the air conditioning control unit 60 operates the three-way valve 52 so that engine cooling water circulates between the engine 10 and the heater core 23, and uses the exhaust heat of the engine 10 to drive the vehicle. The heater unit 53 is controlled to heat the air blown into the room. Note that circulation of engine cooling water between the engine 10 and the heater core 23 at this time is performed by a mechanical water pump installed in the engine 10. In addition, the air conditioning control unit 60 at this time also performs the same control of the heat pump system 30 as in the cooling control. Thereby, the air cooled by the air conditioning evaporator 22 is reheated by the heater core 23 using the exhaust heat of the engine 10, thereby dehumidifying and heating the vehicle interior.

Furthermore, control of the air conditioning control unit 60 for dehumidifying and heating the vehicle interior during electric driving when the engine 10 is stopped will be described. The air conditioning control unit 60 selects either of the following series dehumidifying and heating control or parallel dehumidifying and heating control to dehumidify and heat the vehicle interior during electric driving. Note that the air conditioning control unit 60 determines the dehumidifying and heating efficiency of both controls based on the outside air temperature THA, the target temperature of the vehicle interior ventilation, and the like, and selects the dehumidifying and heating control with higher efficiency. In any of the dehumidification/heating controls, the air conditioning control unit 60 operates the electric water pump 51 and also operates the three-way valve 52 so that engine cooling water circulates between the water/refrigerant heat exchanger 32 and the heater core 23. operating.

In series dehumidification heating control, the air conditioning control unit 60 fully opens the flow rate adjustment valve 39a on the air conditioning evaporator 22 side, fully closes the two electromagnetic on-off valves 47 and 48, and the flow rate adjustment valve 39b on the battery evaporator 34 side, The compressor 31 is operated with the high-stage expansion valve 37 and the low-stage expansion valve 41 in the throttled state. As a result, in the heat pump system 30, heat is transferred from the accumulator tank 35 to compression in the compressor 31, heat radiation to the engine cooling water in the water-refrigerant heat exchanger 32, and expansion in two stages in the outdoor heat exchanger 33 and the air conditioning evaporator 22. , and then return to the accumulator tank 35.

On the other hand, in parallel dehumidification heating control, the air conditioning control unit 60 fully opens the flow rate adjustment valve 39a on the air conditioning evaporator 22 side and the two electromagnetic on-off valves 47, 48, and the high stage expansion valve 37 and the low stage expansion valve 41. The compressor 31 is operated with the compressor in a throttled state. Thereby, the following two refrigerant circulation paths are formed in the heat pump system 30. That is, one of the two refrigerant circulation paths is from the accumulator tank 35 to compression in the compressor 31, heat radiation to the engine cooling water in the water-refrigerant heat exchanger 32, and expansion in the outdoor heat exchanger 33. This is the route that returns to the accumulator tank 35 through the cassette. Another refrigerant circulation route is from the accumulator tank 35 through compression in the compressor 31, heat radiation to the engine cooling water in the water-refrigerant heat exchanger 32, expansion in the air conditioning evaporator 22, and return to the accumulator tank 35. It is.

By the way, when the battery temperature THC rises above a predetermined temperature limit, the driving control unit 66 prohibits electric driving in order to protect the battery 12 from overheating. Then, when the battery temperature THC rises to near the limit temperature, the air conditioning control unit 60 executes forced cooling control of the battery 12 by the heat pump system 30. Forced cooling control of the battery 12 when none of the above air conditioning controls is being performed is performed in the following manner. That is, at this time, the air conditioning control unit 60 stops the electric water pump 51 and operates the three-way valve 52 to cut off the flow of engine cooling water into the heater core 23 . In addition, the air conditioning control unit 60 at this time has the high-stage expansion valve 37, the low-stage expansion valve 41, and the flow rate adjustment valve 39b on the battery evaporator 34 side fully open, and the two electromagnetic on-off valves 47, 48 and the air conditioning After the flow rate adjustment valve 39a on the evaporator 22 side is fully closed, the compressor 31 is operated.

Note that even during execution of air conditioning or dehumidification/heating of the vehicle interior, the battery temperature THC may rise and forced cooling control of the battery 12 may be required. In such a case, it is necessary to adjust the refrigerant discharge amount of the compressor 31 and the opening degree of each flow regulating valve 39a, 39b of the refrigerant distribution mechanism 39 to supply appropriate amounts of refrigerant to the air conditioning evaporator 22 and the battery evaporator 34, respectively. There is. During cooling control and during dehumidification/heating control while the engine is running, the refrigerant that has been compressed by the compressor 31 and turned into a liquid by heat radiation to the outside air in the outdoor heat exchanger 33 flows into the refrigerant distribution mechanism 39 . Therefore, in these cases, the distribution ratio of refrigerant between the air conditioning evaporator 22 and the battery evaporator 34 can be controlled with high accuracy by adjusting the opening degree of both flow rate regulating valves 39a and 39b. On the other hand, during execution of the series dehumidification/heating control and the parallel dehumidification/heating control during electric driving, the heat of the refrigerant is transferred to the engine cooling water in the water-refrigerant heat exchanger 32 after being compressed by the compressor 31. Depending on the amount of heat transferred from the refrigerant to the engine cooling water at this time, the refrigerant flowing into the refrigerant distribution mechanism 39 may be in a gas-liquid mixed state. When the refrigerant is in a gas-liquid mixed state, even if the volumetric flow rate is the same, the mass flow rate will be different depending on the gas-liquid ratio of the refrigerant. on the other hand. Adjustment of the opening degree of the flow rate regulating valves 39a, 39b can only control the volumetric flow rate of the refrigerant passing through. Therefore, when the refrigerant flowing into the refrigerant distribution mechanism 39 is in a gas-liquid mixed state, the adjustment of the opening degrees of both the flow rate regulating valves 39a and 39b does not allow the refrigerant to be distributed between the air conditioning evaporator 22 and the battery evaporator 34. It becomes impossible to accurately control the ratio.

On the other hand, the air conditioning control unit 60 in the hybrid vehicle of the present embodiment is configured to respond when dehumidifying heating and forced cooling of the battery 12 are simultaneously requested during electric driving when the engine 10 has stopped generating heat. requests the travel control unit 66 to switch to engine-operated travel. As a result, by operating the engine 10, that is, by bringing the engine 10 into a state where it generates heat, it is possible to simultaneously perform dehumidifying heating of the passenger compartment and forced cooling of the battery 12. However, due to the interruption of electric driving for simultaneous implementation of such dehumidifying heating and forced cooling of the battery 12, the fuel consumption of the hybrid vehicle increases. In contrast, in the hybrid vehicle of this embodiment, interruption of electric driving is suppressed by performing cooling control of the battery 12 in the manner described below.

FIG. 3 shows a flowchart of a battery cooling control routine executed by the air conditioning control unit 60 for forced cooling control of the battery 12. During startup, the air conditioning control unit 60 repeatedly executes the process of this routine at every predetermined control cycle.

When the process of this routine is started, first in step S100, it is determined whether the outside air temperature THA is equal to or higher than a predetermined low temperature side determination value T1 and less than a predetermined high temperature side determination value T2. If the outside air temperature THA is less than the low-temperature side determination value T1 or higher than the high-temperature side determination value T2 (NO), in step S110, the first temperature LO, which is less than the above-mentioned limit temperature, is set to the cooling start temperature TCC. is set as the value of Further, if the outside air temperature THA is equal to or higher than the low temperature side determination value T1 and lower than the high temperature side determination value T2 (YES), in step S120, the second temperature HI, which is lower than the limit temperature and higher than the first temperature LO, is cooled. It is set as the value of the starting temperature TCC. Note that the following values are set for the low temperature side determination value T1 and the high temperature side determination value T2, respectively. If the outside air temperature THA is sufficiently low, even when the heat generation amount of the battery 12 is at its maximum, the battery temperature THC will not rise above the limit temperature simply by dissipating heat to the outside air without forced cooling by the heat pump system 30. Deterred. The low temperature side determination value T1 is set to the highest value in the range of outside air temperature THA where such forced cooling is unnecessary. Furthermore, when the outside air temperature THA is higher than a certain level, dehumidifying and heating the vehicle interior is not necessary. The high-temperature side determination value T2 is set to the lowest value in the range of outside air temperature THA that does not require dehumidifying heating.

Now, after setting the cooling start temperature TCC in step S110 or step S120, the process proceeds to step S130. Then, in step S130, it is determined whether the battery temperature THC is equal to or higher than the cooling start temperature TCC. If the battery temperature THC at this time is less than the cooling start temperature TCC (NO), the current processing of this routine is ended. On the other hand, if the battery temperature THC is equal to or higher than the cooling start temperature TCC (YES), the process proceeds to step S140.

When the process proceeds to step S140, it is determined in step S140 whether or not the vehicle is traveling electrically. If the vehicle is running on electric power (YES), the process proceeds to step S150, and if the vehicle is not running on electric power (NO), that is, the engine is running, the process proceeds to step S170.

When the process proceeds to step S150, it is determined in step S150 whether or not there is a request to perform dehumidification and heating. If there is a request to perform dehumidifying heating (YES), the process proceeds to step S160, and if there is no request to perform dehumidifying heating (NO), the process proceeds to step S170.

During electric driving, if there is a request to perform dehumidification/heating and the process proceeds to step S160, in step S160, a request to switch to engine operating driving is output to the driving control unit 66, and then the current The processing of this routine is ended. The engine 10 starts operating in response to the request for switching to engine running driving at this time, and enters a state in which it generates heat. That is, in this embodiment, the process in step S160 corresponds to a heat source state switching process that switches the state of the engine 10 as the second heat source to a state in which it generates heat.

On the other hand, if the engine is running or there is no request to perform dehumidification/heating and the process proceeds to step S170, in step S170, the heat pump system 30 for forced cooling of the battery 12 is controlled. After the execution, the processing of this routine ends.

The operation and effects of this embodiment will be explained.
The air conditioning control unit 60 in this embodiment executes forced cooling of the battery 12 by the heat pump system 30 when the battery temperature THC is equal to or higher than the cooling start temperature TCC. Note that due to its structure, the heat pump system 30 cannot simultaneously perform dehumidifying heating of the vehicle interior and forced cooling of the battery 12 during electric driving. Therefore, if the battery temperature THC becomes equal to or higher than the cooling start temperature TCC when dehumidification/heating is requested, the air conditioning control unit 60 requests the travel control unit 66 to switch to running with the engine running. By operating the engine 10, it is possible to simultaneously perform dehumidification and heating of the vehicle compartment and forced cooling of the battery 12.

Moreover, the air conditioning control unit 60 determines that the outside air temperature THA is less than the high temperature side determination value T2, and that there is a high possibility that dehumidification and heating will be performed. Then, when it is determined that the air conditioning control unit 60 is in a state where there is a high possibility of performing dehumidifying heating, the air conditioning control unit 60 sets the value of the cooling start temperature TCC when it is determined that the possibility is low. A second temperature HI higher than the first temperature LO is set as the value of the cooling start temperature TCC. Therefore, since dehumidifying heating and forced cooling of the battery 12 are performed simultaneously, electric driving is less likely to be interrupted.

Note that in this embodiment, when the outside air temperature THA is less than the low temperature side determination value T1, forced cooling of the battery 12 by the heat pump system 30 is normally not necessary. If the battery temperature THC rises close to the limit temperature in a situation where the outside air temperature THA is less than the low temperature side determination value T1, there is a possibility that some abnormality has occurred in the battery 12. Therefore, when the outside air temperature THA is less than the low temperature side determination value T1, forced cooling of the battery 12 is started early by setting the first temperature LO, which is lower than the second temperature HI, as the value of the cooling start temperature TCC. I try to do that.

According to the hybrid vehicle of the present embodiment described above, the following effects can be achieved.
(1) In this embodiment, when it is determined that there is a high possibility of performing dehumidifying heating, the cooling start temperature TCC, which is the battery temperature THC at which the heat pump system 30 starts forced cooling of the battery 12, is set. The value is set to a lower temperature than when it is determined that the same possibility is low. Therefore, simultaneous implementation of dehumidifying and heating the vehicle compartment and forced cooling of the battery 12 makes it difficult for electric driving to be interrupted, and an increase in fuel consumption of the hybrid vehicle due to such interruption is suppressed.

(2) In a situation where the outside air temperature THA is low and it is difficult for the battery temperature THC to rise, the first temperature LO is set as the value of the cooling start temperature TCC, which is the same as when the possibility of implementing dehumidifying heating is low. . Therefore, when the battery temperature THC increases due to an abnormality in the battery 12, forced cooling of the battery 12 can be started early.

This embodiment can be modified and implemented as follows. This embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
- Dehumidification and heating of the vehicle interior during electric driving may be performed using only one of the series dehumidification and heating control and the parallel dehumidification and heating control. Note that if parallel dehumidification heating is not performed and only serial dehumidification heating control is performed, the refrigerant passages 45 and 46 and the electromagnetic on-off valves 47 and 48 in the heat pump system 30 may be omitted.

- Even when the outside air temperature THA is less than the low temperature side determination value T1, the second temperature HI may be set as the value of the cooling start temperature TCC.
- It may be determined whether or not there is a high possibility that dehumidification and heating will be performed based on information other than the outside air temperature THA, such as the vehicle interior temperature and the operation status of the air conditioning operation panel 65.

- A heat exchanger between the refrigerant compressed by the compressor 31 and air may be installed in the air conditioning case 20, and the heater unit 53 may be configured so that the heat exchanger heats the air using the refrigerant as a heat source. In this case, the heater core 23, which is a heat exchanger between engine cooling water and air, and the heat exchanger between refrigerant and air are installed in the air conditioning case 20.

- In the above embodiment, the battery 12 is forcedly cooled by the heat pump system 30, but in-vehicle equipment other than the battery 12, such as an inverter, may be forcedly cooled.

- In the above embodiment, the heater unit 53 was configured to use the engine 10 as the second heat source. For example, the heater unit 53 may be configured to use a heat source other than the refrigerant compressed by the compressor 31 and the engine 10 as the second heat source, such as a hot wire heater that generates heat in response to energization. Even in such cases, if the state of the second heat source is switched from the state where heat generation is stopped to the state where heat is generated, the energy for the second heat source to generate heat will be consumed, and the energy consumption of the vehicle will increase. do. Therefore, if it is determined that there is a high possibility that dehumidifying heating will be performed, a higher temperature will be set as the cooling start temperature of the in-vehicle equipment than if it is determined that the same possibility is not high. Due to the demand for simultaneous dehumidification heating and cooling of in-vehicle equipment, if the state of the second heat source is made difficult to switch from a state in which heat generation is stopped to a state in which heat generation is performed, dehumidification and heating of the cabin of a hybrid vehicle and in-vehicle equipment Energy consumption for equipment cooling is reduced.

10...Engine (second heat source)
11...Motor 12...Battery (vehicle equipment)
20...Air conditioning case 21...Blower 22...Air conditioning evaporator 23...Heater core 24...Mixture door 30...Heat pump system 31...Compressor 32...Water refrigerant heat exchanger 33...Outdoor heat exchanger 34...Battery evaporator 35...Accumulator tank 36... High pressure refrigerant passage 37...High stage side expansion valve 38...Low pressure refrigerant passage 39...Refrigerant distribution mechanism 39a, 39b...Flow rate adjustment valve 40, 44...Check valve 41...Low stage side expansion valve 42...Constant pressure valve 43...Expansion valve 45 , 46... Refrigerant passage 47, 48... Electromagnetic shut-off valve 50... Heater water circuit 51... Electric water pump 52... Three-way valve 53... Heater unit 60... Air conditioning control unit 61... Arithmetic processing unit 62... Memory device 63... Outside temperature sensor 64 ...Battery temperature sensor 65...Air conditioning operation panel 66...Travel control unit

Claims (1)

A hybrid vehicle comprising a heat pump system that recovers heat from outside air to heat a vehicle interior, and an air conditioning control unit that controls the heat pump system,
The heat pump system includes:
A compressor that compresses refrigerant;
A heater that is a unit that heats air that is blown into a vehicle interior, and that can use both the refrigerant compressed by the compressor and a second heat source that is a heat source other than the refrigerant as a heat source for heating the air. unit and
an outdoor heat exchanger that exchanges heat between the refrigerant and outside air;
an air conditioning evaporator that cools the air flowing into the heater unit using the heat of vaporization of the refrigerant;
an evaporator for onboard equipment that cools onboard equipment using heat of vaporization of the refrigerant;
A refrigerant distribution mechanism that distributes the refrigerant that has passed through the heater unit to the air conditioning evaporator and the vehicle-mounted equipment evaporator, the refrigerant distribution mechanism adjusting the distribution ratio of the refrigerant to both evaporators;
and a system that performs dehumidification and heating of the vehicle interior by cooling the air by the air conditioning evaporator and heating the air by the heater unit,
The air conditioning control unit includes:
an operation process of operating the refrigerant distribution mechanism so that the vehicle-mounted device evaporator cools the vehicle-mounted device when the temperature of the vehicle-mounted device is equal to or higher than a cooling start temperature;
a heat source state in which the state of the second heat source is switched to a state in which heat is generated when simultaneous implementation of cooling of the in-vehicle equipment and dehumidifying/heating is requested when the second heat source is in a state where it has stopped generating heat; switching processing and
Determining whether or not there is a high possibility of implementing the dehumidifying heating, and if it is determined that the dehumidifying heating is likely to be performed, the system is not in a state where the possibility is high. a setting process of setting a higher temperature as the value of the cooling start temperature than when it is determined that
A hybrid vehicle is a unit that implements this.