JP2021035104A - Vehicular cooling device - Google Patents

Abstract

To provide a vehicular cooling device capable of securing travel safety of a vehicle while suppressing deterioration of comfort in a cabin at the occurrence of a battery cooling request accompanying a temperature rise of a battery.SOLUTION: A vehicular cooling device 1 includes: an electric motor 3; a battery 4; a battery temperature sensor TS33; an air conditioner 10; a battery cooling device 30 which cools the battery 4 using coolant of the air conditioner 10; and a control device 50 which controls the air conditioner 10, generates a battery cooling request when a battery temperature TB is a first temperature T1 or more, and controls the battery cooling device 30. The control device 50 executes first control processing for giving preference to an air conditioning request over a cooling request when the battery temperature TB is less than a second temperature T2, and executes second control processing for giving preference to the cooling request over the air conditioning request when the battery temperature TB is the second temperature T2 or more.SELECTED DRAWING: Figure 5

Description

The present invention relates to a vehicle cooling device, and more particularly to a vehicle cooling device that air-conditions the interior of a vehicle and cools a battery that supplies electric power to an electric motor that drives the vehicle.

Conventionally, there is known a technique of cooling a battery that supplies electric power to an electric motor for driving a vehicle by using a refrigerant used for air conditioning (see, for example, Patent Document 1). In the cooling device described in Patent Document 1, when there is a battery cooling request and the priority of battery cooling is low, refrigerant is supplied to both the heat exchanger for air conditioning and the heat exchanger for battery cooling to cool the battery. When the priority of is high, the refrigerant is supplied only to the heat exchanger for cooling the battery.

Japanese Unexamined Patent Publication No. 2012-248393

However, in the cooling device of Patent Document 1, cooling control is simply performed according to the priority of battery cooling. That is, Patent Document 1 does not specifically describe on what basis the cooling control is switched. Further, in the cooling device of Patent Document 1, when there is an air conditioning requirement for adjusting the temperature inside the vehicle interior, and when the priority of battery cooling is low, the rotation of the electric compressor so as to satisfy both the air conditioning requirement and the battery cooling requirement at the same time. The number is speed-adjusted.

As described above, in Patent Document 1, when the priority of battery cooling is low, both the air conditioning requirement and the battery cooling requirement are satisfied, and when the priority of battery cooling is high, the battery cooling requirement is satisfied. Is met, but air conditioning requirements are being ignored.

Therefore, in the cooling device of Patent Document 1, when the battery output is limited due to the temperature rise of the battery, the running safety of the vehicle is lowered while suppressing the deterioration of the vehicle interior comfort that may be caused by this limitation ( There was room for improvement in securing (insufficient vehicle driving force).

The present invention has been made to solve such a problem, and when a battery cooling request is generated due to a rise in battery temperature, the driving safety of the vehicle is improved while suppressing a decrease in comfort in the vehicle interior. It is an object of the present invention to provide a vehicle cooling device that can be secured.

In order to achieve the above object, the present invention is a vehicle cooling device, the electric motor that generates the driving force of the vehicle, the battery that supplies power to the electric motor, and the battery temperature sensor that detects the temperature of the battery. , An air conditioner that air-conditions the interior of the vehicle using a refrigerant, a battery cooling device that cools the battery using the refrigerant of the air conditioner, and a battery detection while controlling the air conditioner based on the air conditioning request by the vehicle occupants. The control device comprises a control device that generates a battery cooling request when the temperature is equal to or higher than a predetermined first temperature and controls the battery cooling device to cool the battery based on the battery cooling request, and the control device is air-conditioned. If there is a requirement and a battery cooling requirement, and the detected temperature of the battery is less than the second temperature set to a temperature higher than the first temperature, the air conditioner and the battery are prioritized over the battery cooling requirement. When the first control process for controlling the cooling device is executed, there is an air conditioner request and a battery cooling request, and the detected temperature of the battery is the second temperature or higher, the air conditioner is prioritized over the air conditioner request for air conditioning. It is characterized in that it is configured to execute a second control process for controlling the device and the battery cooling device.

According to the present invention configured in this way, in addition to the air conditioning request by the occupant, when the battery cooling request is generated (the battery temperature is generated at the first temperature or higher), the air conditioning request and the battery cooling request are generated. It is necessary to supply the refrigerant of the air conditioner to satisfy. Therefore, when the amount of refrigerant supplied is insufficient, it is necessary to distribute the refrigerant according to the air conditioning request and the battery cooling request. Therefore, in the present invention, when the battery temperature is in a relatively low temperature range (specifically, less than the second temperature), it is unlikely to affect the running safety of the vehicle. The comfort inside the vehicle can be improved. On the other hand, in the present invention, when the battery temperature is in a relatively high temperature range (specifically, the second temperature or higher), even if the comfort in the vehicle interior is reduced, the battery cooling requirement is prioritized and the vehicle travels. It is possible to prevent a decrease in safety.

Further, preferably in the present invention, the control device limits the output allowable power of the battery so that the output allowable power of the battery decreases as the temperature of the battery rises, and the second temperature is the battery at the second temperature. The output allowable power is set to be the minimum power that the motor can generate a predetermined driving force.
According to the present invention configured as described above, if the battery temperature is lower than the second temperature, the battery can supply the minimum electric power to the electric motor. Thereby, in the present invention, if the battery temperature is lower than the second temperature, it is possible to suppress the deterioration of the traveling safety of the vehicle while giving priority to the air conditioning request by the occupant for good interior comfort.

Further, preferably in the present invention, in the second control process, the control device supplies the battery cooling device with the amount of the refrigerant required for the battery cooling request among the refrigerants of the predetermined flow rate provided by the air conditioner, and the battery cooling device. The air conditioner is controlled so as to air-condition the passenger compartment using the refrigerant left unsupplied to the vehicle interior.
According to the present invention configured in this way, when the battery temperature is the second temperature or higher, the refrigerant is preferentially supplied to the battery cooling device, so that the battery is surely cooled and the running safety of the vehicle is improved. Can be secured

Further, preferably in the present invention, the control device has a predetermined flow rate provided by the air conditioner when the detection temperature of the battery is set to a temperature higher than the second temperature in the second control process. The entire amount of refrigerant is supplied to the battery cooling device.
According to the present invention configured in this way, when the battery temperature is the third temperature or higher, the battery temperature becomes too high by using all the refrigerant for the battery cooling with priority given to the battery cooling over the air conditioning. It is possible to prevent the vehicle from becoming inoperable.

Further, preferably in the present invention, the battery cooling device cools the battery by direct heat exchange between the refrigerant and the battery.
According to the present invention configured as described above, the cooling heat of the refrigerant can be directly applied to the battery without using an intermediate medium (water or the like) to cool the battery. Thereby, in the present invention, it is possible to prevent the occurrence of loss caused by heat exchange between the refrigerant and the intermediate medium and the increase in size of the apparatus.

Further, preferably in the present invention, the control device sets a larger air conditioning requirement as the temperature difference between the actual temperature in the vehicle interior and the target temperature set by the occupant is larger.
According to the present invention configured as described above, the air conditioning requirement can be appropriately set based on the temperature difference between the target temperature in the vehicle interior and the actual temperature.

According to the vehicle cooling device of the present invention, when a battery cooling request is generated due to an increase in battery temperature, it is possible to ensure the running safety of the vehicle while suppressing a decrease in comfort in the vehicle interior.

It is a block diagram of the vehicle cooling system of the embodiment of this invention. It is explanatory drawing of the vehicle cooling system of embodiment of this invention. It is operation | movement explanatory drawing of the refrigerant in the cooling mode of the vehicle cooling device of embodiment of this invention. It is operation | movement explanatory drawing of the refrigerant in the heating mode of the vehicle cooling system of an embodiment of this invention. It is a graph explaining the influence which the battery temperature has on the running performance and the comfort performance in a vehicle interior in the embodiment of the present invention. It is a flowchart which shows the cooling process of the vehicle cooling device of embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
First, the configuration of the vehicle cooling device according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a configuration diagram of a vehicle cooling device, and FIG. 2 is an explanatory diagram of a vehicle cooling device.

As shown in FIGS. 1 and 2, the vehicle cooling device 1 of the present embodiment includes an electric motor (electric motor) 3 that generates a driving force for the vehicle, a battery 4 that supplies electric power to the electric motor 3, and an air conditioner. A battery cooling device 30 and a control device 50 for controlling the battery cooling device 30 are provided. The vehicle is an electric vehicle (EV) equipped with an electric motor 3. Since the vehicle does not have an internal combustion engine (gasoline engine or the like), only the electric motor 3 generates the driving force of the vehicle.

The air conditioner 10 performs air conditioning (cooling and heating) in the vehicle interior using a refrigerant (for example, HFO-1234yf) in response to an air conditioning request from an occupant. On the other hand, the battery cooling device 30 is connected to the airport device 10 and cools the battery 4 by using the refrigerant of the air conditioner 10.

The battery 4 supplies electric power to the electric motor 3, the compressor 12, which will be described later, and other electric components. However, since the electric power to other electric parts is small, in the present embodiment, the battery 4 will be described as supplying electric power only to the electric motor 3 and the compressor 12.

The battery 4 has 16 battery modules electrically connected to each other. Each battery module includes a plurality of battery cells (lithium ion battery cells) connected in series. Since the internal resistance of the battery 4 decreases as the temperature rises, the power that can be output increases. However, the higher the temperature of the battery 4, the more easily the deterioration progresses. Therefore, in this embodiment, as the temperature rises, can be output power of the battery 4 (allowable output power P _L) is configured to be restricted.

The control device 50 controls the air conditioner 10 and the battery cooling device 30 so as to satisfy the air conditioning requirement and the battery cooling requirement. The control device 50 generates an air conditioning request based on _{the target temperature TT GT} in the vehicle interior set by the occupant via the air conditioning panel. The greater the temperature difference between the actual temperature T _{CAB in the} vehicle interior and the target temperature T T _GT T, the greater the magnitude of the air conditioning requirement. Further, when the temperature of the battery 4 (hereinafter, also referred to as “battery temperature”) becomes equal to or higher than a predetermined first temperature T1 (for example, a fixed temperature of 40 to 45 ° C.), the control device 50 requests a battery cooling of a predetermined size. The battery cooling requirement is maintained until the battery temperature drops to a first temperature T1 or lower (eg, a temperature 5-10 ° C. lower than the first temperature T1). In the present embodiment, the battery cooling requirement is a constant value, but the present invention is not limited to this, and the higher the battery temperature, the larger the battery cooling requirement may be set.

Since the air conditioner 10 is a general heat pump type air conditioner, detailed description thereof will be omitted. The air conditioner 10 includes a refrigerant circulation flow path pipe 11, and the pipe 11 has a compressor (compressor) 12, a heater core 13, a two-way valve 14, an expansion valve 15, and an outdoor heat exchanger 16, a three-way valve. 17, the air conditioning valve 18, the evaporator 19, and the accumulator 20 are arranged in this order.

The compressor 12 compresses and outputs the refrigerant. The compressor 12 receives electric power from the battery 4, and as the input electric power to the compressor 12 increases, the rotation speed increases and the discharge flow rate increases. The larger the discharge flow rate of the refrigerant, the higher the cooling capacity of the vehicle cooling device 1. In this embodiment, the compressor 12 provides a maximum _{discharge flow rate at a maximum output of PMAX} (eg, 5 kW). This maximum discharge flow rate is set to satisfy the maximum air conditioning requirements. Therefore, when the battery cooling requirement is added to the air conditioning requirement, this maximum discharge flow rate may not be able to satisfy these requirements at the same time.

The heater core 13 is a heat exchanger that dissipates heat to the air conditioning air sent to the vehicle interior in the heating mode. The two-way valve 14 and the expansion valve 15 are arranged in parallel. The refrigerant passes through the two-way valve 14 in the cooling mode and through the expansion valve 15 in the heating mode (and when there is no battery cooling request). The outdoor heat exchanger 16 exchanges heat between the air taken in from the outside of the vehicle and the refrigerant. The outdoor heat exchanger 16 is provided with a radiator fan 16a that blows air to the outdoor heat exchanger 16 and a movable shutter grill 16b that adjusts the amount of outside air air to the outdoor heat exchanger 16.

The three-way valve 17 is a switching valve for sending the refrigerant output from the outdoor heat exchanger 16 to either the cooling pipe 11a or the heating pipe 11b. The air conditioning valve 18 and the evaporator 19 are arranged in the cooling pipe 11a. The air conditioning valve 18 is a valve that can reduce the pressure of the refrigerant and linearly adjust the flow rate. The evaporator 19 is a heat exchanger that exchanges heat (heat absorption) between the refrigerant decompressed by the air conditioning valve 18 and the air for air conditioning in the cooling mode. The heating pipe 11b joins the cooling pipe 11a on the upstream side of the accumulator 20.

The evaporator 19 is arranged in the air flow path 21 for air conditioning. The blower fan 22 arranged in the air flow path 21 blows air toward the evaporator 19. The air mix damper 23 switches whether or not air passes through the heater core 13 downstream of the evaporator 19. A PCT heater 24 is attached to the heater core 13.

The battery cooling device 30 includes a battery pipe 31, and the battery pipe 31 branches off from the cooling pipe 11a on the downstream side of the three-way valve 17 and joins the cooling pipe 11a on the upstream side of the accumulator 20. A battery cooling valve 32 and a heat exchanger 33 for cooling the battery are arranged in this order in the battery pipe 31. The battery cooling valve 32 is a valve that can reduce the pressure of the refrigerant and linearly adjust the flow rate. The heat exchanger 33 is configured to directly exchange heat between the battery 4 and the refrigerant without using an intermediate medium (water or the like). That is, in the present embodiment, heat exchange between the refrigerant and the intermediate medium and heat exchange between the intermediate medium and the battery 4 are unnecessary.

Further, a plurality of temperature sensors for measuring the temperature of the refrigerant and a plurality of pressure sensors for measuring the pressure of the refrigerant are arranged on the pipes 11 and 31. The temperature sensors include a temperature sensor TS11 that detects the temperature of the refrigerant in the pipe 11 output from the outdoor heat exchanger 16, a temperature sensor TS21 that detects the inlet temperature of the refrigerant in the pipe 31 that flows into the heat exchanger 33, and heat. Includes a temperature sensor TS 22 that detects the outlet temperature of the refrigerant in the pipe 31 flowing out of the exchanger 33.

Further, each of the 16 battery modules of the battery 4 is provided with a battery temperature sensor TS33 that detects the temperature of the battery module. Each temperature sensor TS33 is located on the cold side of the corresponding battery module (ie, downstream of the heat exchanger 33). Further, an outside air temperature sensor TS31 for measuring the outside _{air temperature T AMB} of the vehicle and a vehicle interior temperature sensor TS 32 for measuring the vehicle interior temperature _{T CAB are provided.}

The pressure sensors are a pressure sensor PS11 that detects the discharge pressure of the refrigerant flowing through the pipe 11 on the output side (downstream side) of the compressor 12, and a pressure sensor that detects the pressure of the refrigerant flowing through the pipe 31 on the downstream side of the heat exchanger 33. Includes PS21.

The control device 50 includes a plurality of ECUs in this embodiment. Each ECU is a computer device equipped with a processor, a memory for storing various programs, a data input / output device, and the like. These ECUs are communicably connected via an in-vehicle communication line and function as a control device for the vehicle cooling device 1.

Specifically, as shown in FIG. 2, the control device 50 mainly controls the air conditioner device 10 with an air conditioner ECU (heat pump ECU or HP-ECU) 51, and a cooling function of the battery 4 under the air conditioner ECU 51. It includes a battery ECU (B-ECU) 52 that controls, a power train control module (PCM) 53 that controls the power train of a vehicle, and a motor ECU (M-ECU) 54 that controls the electric motor 3. In the present embodiment, the control device 50 includes a plurality of computer devices, but the present invention is not limited to this, and the control device 50 may be configured by a single computer device.

The battery ECU 52 is arranged in the battery pack. Battery ECU52 receives the measured temperature T _BM from 16 temperature sensors TS 33, selects the highest temperature among these measured temperature T _BM, and outputs to the PCM53 the selected temperature as the battery temperature T _{B. Further, the battery ECU 52 outputs the measured values T IN} , T _OUT , and P _OUT of the temperature sensor TS 21, the temperature sensor TS 22, and the pressure sensor PS 21 to the air conditioning ECU 51. _{Further, the battery ECU 52 outputs an operation command S BV} instructing the opening / closing operation to the battery cooling valve 32, and receives a valve position indicating the valve opening / closing position from the battery cooling valve 32. Battery ECU52, based on the operation command and the valve position, to determine the initial state and fault states of the battery cooling valve 32, the determination result S _VP, and outputs the S _F to the air conditioning ECU 51.

Maximum PCM53 is a map showing the relationship between the output allowable power P _L of the battery temperature T _B and the battery 4 stores in memory, on the basis of the map and the battery temperature T _B, the battery 4 which can be output power (output limiting power or output allowable power) is calculated P _L. PCM53 outputs the output power limit P _L to the air conditioning ECU51.

In the present embodiment, PCM53 is, but to calculate the output power limit P _L of the battery 4 is not limited to this, the battery ECU52 or air conditioning ECU51 is, the battery 4 based on the map above the battery temperature T _B output limit power P _L of may be calculated.

Further, the PCM 53 instructs the motor ECU 54 of the torque output by the electric motor 3. In this case, the indicated torque output by the PCM53, output limit power P _L (or, from the output limit power P _L, power obtained by subtracting the predetermined power required for operation of the compressor 12) and the current rotational speed of the electric motor 3 It is limited to the maximum output torque of the electric motor 3 calculated based on the above. The motor ECU 54 controls the electric motor 3 via a motor drive circuit (inverter circuit or the like) 3a based on the indicated torque.

Further, PCM53, based on the battery temperature T _B, generates a battery cooling request R _BC, and outputs a battery cooling request R _BC to the air conditioning ECU 51. The battery cooling request R _BC includes a battery cooling request of a predetermined size (constant value) and a required level for cooling the battery 4. The constant value battery cooling requirement is represented by the power P2com (eg, a fixed power of 2-3 kW) that drives the compressor 12.

Request level, battery temperature T _B first temperature is predetermined T1 (e.g., 40 to 45 ° C.) "0" (no battery cooling requirements) less than the first temperature T1 or more and a predetermined second temperature T2 (for example, "1" (first battery cooling request) below (fixed temperature of 50-60 ° C), "2" (second) below second temperature T2 and less than third temperature T3 (eg, fixed temperature of 60-60 ° C) Battery cooling request), "3" (third battery cooling request) at a third temperature T3 or higher.

Further, the PCM 53 sends an operation command to the compressor 12 to control the rotation speed based on _{the compressor required rotation speed R COM} received from the air conditioning ECU 51. Further, the PCM 53 sends an operation command to the radiator fan 16a to control the rotation speed based on the radiator fan required rotation speed R _{RAD received from the air conditioning ECU 51.} Further, PCM53, based on the shutter grille opening and closing request R _SG received from the air conditioner ECU 51, thereby opening and closing operation by sending an operation command for the shutter grille 16b. Furthermore, PCM53 is ambient temperature T _AMB received from the outside air temperature sensor TS31, the pressure P _COM received from the pressure sensor PS11, and outputs to the air conditioning ECU 51.

Conditioning ECU51 receives the air-conditioning set S _AC by a passenger to operate the air-conditioning panel. The air conditioning setting S _AC includes ON / OFF of the air conditioning mode (cooling mode, heating mode, OFF) and the target temperature _{TT GT} . The air-conditioning ECU 51 has a variable size according to the temperature difference between _{the target temperature T TGT} in the vehicle interior set by _{the air-conditioning setting S AC and the vehicle interior temperature T CAB} (actual temperature) indicated by the vehicle interior temperature sensor TS32. Generate air conditioning requirements. The air conditioning requirement includes the electric power P1com (for example, variable power of 0 to 5 kW) for driving the compressor 12, and the required rotation speed of the radiator fan.

The air conditioning ECU 51 calculates the total electric power (P1com + P2com) for operating the compressor 12 based on the air conditioning request (P1com) and the battery cooling request (P2com). However, the total power can not exceed the maximum output P _MAX of the compressor 12 (5 kW), further, the residual power by subtracting the drive power P _M of the electric motor 3 from the output power limit P _L of the battery 4 P _R (= P _L -P _M) can not exceed. Therefore, air conditioning ECU51, in response to the battery cooling required level, the total power of the air conditioning requirements for power and battery cooling power so as not to exceed the residual power P _R, to calculate the air-conditioning command for power and battery cooling power .. In other words, the residual power P _R is distributed appropriately to the air conditioning requirements for power and battery cooling power. Incidentally, the air conditioning ECU51 in order to ensure a predetermined total power and also limit the drive power P _M.

Also, the air conditioning ECU51 includes a conditioning demand, based on the battery cooling requirements R _BC battery cooling request size shown (and its required level), operation command S _AV for instructing opening and closing operations of the air conditioning valve 18, and the battery cooling _{The operation command S BV} instructing the opening / closing operation of the valve 32 is output. The operation command _SAV is output directly to the air conditioning valve 18. The operation command S _BV is output to the battery cooling valve 32 via the battery ECU 52.

_{Further, the air conditioning ECU 51 has a valve signal S V3} so as to switch the flow path of the three-way valve 17 according to the cooling mode and the heating mode, and a valve so as to close the two-way valve 14 when there is no battery cooling request in the heating mode. Output signal S _V2.

Next, with reference to FIG. 3, the flow path of the refrigerant in the cooling mode and the heating mode will be described. FIG. 3A is an explanatory diagram of the operation of the refrigerant in the cooling mode, and FIG. 3B is an explanatory diagram of the operation of the refrigerant in the heating mode.

When there is no battery cooling request in the cooling mode (requirement level = 0), the operation of the refrigerant is the same as the operation in a normal heat pump type air conditioner as shown in FIG. 3A (1), and detailed description thereof will be omitted. .. In this mode, the battery cooling valve 32 is fully closed. The refrigerant (low pressure gas) is compressed by the compressor 12 and passes through the outdoor heat exchanger 16 as high pressure gas. The refrigerant (high pressure liquid) liquefied by heat dissipation in the outdoor heat exchanger 16 is depressurized by the air conditioning valve 18 and passes through the evaporator 19 as a low pressure liquid. The refrigerant vaporized by endothermic heat in the evaporator 19 returns to the compressor 12 as a low-pressure gas. The air conditioning air from the blower fan 22 is radiated by the evaporator 19 and supplied to the vehicle interior as cold air.

When there is a battery cooling request in the cooling mode (request level = 1 or 2), as shown in FIG. 3A (2), the vehicle cooling device 1 operates in the air conditioning priority mode or the second battery cooling priority mode. In these modes, the valve openings of the air conditioning valve 18 and the battery cooling valve 32 are adjusted so that the high-pressure liquid refrigerant output from the outdoor heat exchanger 16 defines the cooling pipe 11a and the battery pipe 31. It flows at the flow rate ratio of. The refrigerant flowing through the cooling pipe 11a flows in the same manner as in FIG. 3A (1). On the other hand, the refrigerant flowing through the battery pipe 31 is depressurized by the battery cooling valve 32 and passes through the battery cooling heat exchanger 33 as a low-pressure liquid. In the heat exchanger 33, the refrigerant exchanges heat with the battery 4 to cool the battery 4. At this time, the refrigerant is vaporized by endothermic and returns to the compressor 12 as a low-pressure gas.

When there is a battery cooling request in the cooling mode (request level = 3), as shown in FIG. 3A (3), the vehicle cooling device 1 operates in the first battery cooling priority mode. In this mode, the air conditioning valve 18 is fully closed. Therefore, the high-pressure liquid refrigerant output from the outdoor heat exchanger 16 flows through the battery pipe 31. The high-pressure liquid refrigerant is depressurized by the battery cooling valve 32 and passes through the battery cooling heat exchanger 33 as the low-pressure liquid. In the heat exchanger 33, the refrigerant exchanges heat with the battery 4 to cool the battery 4. At this time, the refrigerant is vaporized by endothermic and returns to the compressor 12 as a low-pressure gas.

For reference, the operation of the refrigerant in the heating mode will be described with reference to FIG. 3B. In the heating mode, the air conditioning valve 18 is fully closed, and the refrigerant does not flow through the cooling pipe 11a. When there is no battery cooling requirement in the heating mode (requirement level = 0), the operation of the refrigerant is the same as the operation in a normal heat pump type air conditioner as shown in FIG. 3B (1). In this mode, the refrigerant is compressed by the compressor 12 and passes through the heater core 13 as a high pressure gas. The refrigerant (high pressure liquid) radiated and liquefied by the heater core 13 is depressurized by the expansion valve 15 and passes through the outdoor heat exchanger 16 as a low pressure liquid. The refrigerant vaporized by endothermic heat in the outdoor heat exchanger 16 returns to the compressor 12 as low-pressure gas through the heating pipe 11b.

On the other hand, when there is a battery cooling request in the heating mode (request level = 1 to 3), as shown in FIG. 3B (2), the three-way valve 17 is set at a valve position such that the refrigerant is sent to the battery pipe 31. The battery cooling valve 32 is set to the open state. In this mode, the refrigerant is compressed by the compressor 12 and passes through the heater core 13 as a high pressure gas. The refrigerant (high pressure liquid) radiated and liquefied by the heater core 13 passes through the two-way valve 14 instead of the expansion valve 15 and passes through the outdoor heat exchanger 16 as a high pressure liquid. The refrigerant (high pressure liquid) radiated by the outdoor heat exchanger 16 is depressurized by the battery cooling valve 32 and passes through the heat exchanger 33 for cooling the battery as a low pressure liquid. In the heat exchanger 33, the refrigerant exchanges heat with the battery 4 to cool the battery 4. At this time, the refrigerant is vaporized by endothermic and returns to the compressor 12 as a low-pressure gas.

Next, with reference to FIG. 4, the influence of the battery temperature on the battery cooling and the air conditioning in the present embodiment will be described. FIG. 4 is a graph illustrating the effect of battery temperature on driving performance and vehicle interior comfort performance. As described above, in this embodiment, in order to suppress the deterioration of the battery 4, in response to an increase in the battery temperature T _B, the output allowable power P _L of the battery 4 is configured to be restricted.

As shown in FIG. 4 (a), the battery 4, the battery temperature T _B is predetermined fourth temperature T4 (e.g., 50-55 ° C.) In the following, the output allowable power P _L is not limited to, vehicle travel Can provide a given output (eg, 100-130 kW) for (100%). On the other hand, the battery 4, the battery temperature T _B is the third temperature T3 (for example, 60~65 ℃ .T3> T4) In the above, the output allowable power P _L is limited to substantially 0%, the vehicle travel Because of the inability to provide power (0%). Therefore, the battery temperature T _B is in the third temperature T3 or more, the vehicle is unable running. Also, between the battery temperature T _B is in the fourth temperature T4 and the third temperature T3, with increasing battery temperature T _B, the output allowable power P _L gradually between 0% to 100% of the predetermined output restriction Will be done.

FIG. 4 (d), the output allowable power P _L of restriction of the battery 4, shows the effects on running performance. Battery temperature T _B is in the fourth temperature T4 below, the output allowable power P _L is not limited, the running performance is not reduced. In FIG. 4 (d), the output allowable power P when the battery temperature T _B is the second temperature T2 (T4 <T2 <T3) L is the minimum power P required to ensure the running safety of the vehicle Corresponds to _SET. This electric power P _SET (for example, 35 kW) is used to generate the electric power P2com (for example, 2 kW) for cooling the battery 4 and the minimum driving force required for the running safety of the vehicle by the electric motor 3. It is set to the total value with the drive power P _{MIN (for example, 33 kW).} The driving power P _MIN is a power value set so that the vehicle can achieve the minimum acceleration for emergency avoidance or the like.

Therefore, if the battery 4 can supply at least the electric power P _SET or more, the electric motor 3 is cooled to the second temperature T2 or less and the driving force equal to or more than the predetermined driving force is applied to the electric motor 3 by the accelerator operation of the occupant. Can be generated. As a result, the vehicle can perform an emergency avoidance operation or the like without finally causing serious thermal damage to the battery 4.

When the power P2 com is not taken into consideration, the power P _SET becomes equal to the drive power P _MIN, and the second temperature T2 can be set to a higher temperature. However, if the power P _SET does not include power P2com, since the battery temperature T _B would quickly reach a third temperature T3, the driving impossible state. Therefore, the power P _SET needs to include the power P2com.

Thus, between the battery temperature T _B is in the fourth temperature T4 and the second temperature T2, the battery 4 can supply more power driving power P _MIN to the electric motor 3. Therefore, when the occupant depresses the accelerator, a driving force exceeding a predetermined minimum driving force is generated, so that the running safety of the vehicle does not deteriorate. However, there may be cases where the acceleration required by the occupant cannot be achieved (driving force reduced state).

Meanwhile, between the battery temperature T _B is the second temperature T2 and the third temperature T3, the battery 4 can not be supplied to the electric motor 3 only from the output allowable power P _L at the maximum to the power minus the power P2com. This power is smaller than the drive power P _MIN. Therefore, even if the occupant depresses the accelerator, only a driving force equal to or less than a predetermined minimum driving force can be obtained, so that the running safety of the vehicle is lowered (driving force insufficient state). Further, when the battery temperature T _B exceeds the third temperature T3, because they are not substantially the power supply from the battery 4 to the electric motor 3, the vehicle becomes incapable traveling (traveling impossible state).

Further, as shown in FIG. 4 (b), the battery temperature T _B is at a temperature Ta (T1 <Ta <T4) below, can charge the battery 4 with the maximum charging current using an external charger (e.g., 120A) although (100%), at a battery temperature T _B is the fourth temperature T4 or more, it is impossible to charge the battery 4 with an external charger (0%). Also, between the battery temperature T _B is the temperature Ta and the fourth temperature T4, the charging current of the external charger, with increasing battery temperature is gradually restricted between 100% to 0%

FIG. 4 (e) is the output allowable power P _L of restriction of the battery 4, it illustrates the effect on the charging performance. Battery temperature T _B is less than or equal to the temperature Ta, since the charging current is not limited, the charging performance does not decrease. Also, between the battery temperature T _B is the temperature Ta and the fourth temperature T4, the charging current is gradually limited, require a longer charge time (charge time increasing state). Also, the battery temperature T _B is in the fourth temperature T4 or more, that charging is impossible (charge disabled state).

Further, as shown in FIG. 4 (c), when the battery temperature T _B is increased to the temperature _{T CUT (T CUT> T3)} , the battery ECU52 is turned off the contactor to be connected to the battery 4 load (electric motor 3 or the like) (Open) to disconnect the battery 4 from the load. FIG. 4 (f) shows the effect of the battery temperature on the battery connection status. That is, the battery temperature T _B is at a temperature T _CUT or more, a battery cut-off state.

Further, FIG. 4 (g), the battery temperature T _B indicates the effect on the performance of the defroster of the vehicle. The defroster can defrost the windshield and the like by using air conditioning air. Since fogging can occur during driving, it is evaluated that the safety of the vehicle is reduced while the defroster is operating. In the present embodiment, the battery temperature T _B is the third temperature T3 or higher (traveling impossible state), since the vehicle is stopped, the safety is assessed as not reduced. On the other hand, the battery temperature T _B is less than the third temperature T3, because the vehicle is capable of traveling, a state where the safety is lowered.

Further, FIG. 4 (h) shows the effect of the battery temperature T _B is given to the starting of the air conditioning performance (cool-down performance). Normally, after the air conditioner is started in the cooling mode, warm air is supplied to the passenger compartment instead of cold air from the air outlet for a while. This is a phenomenon caused irrespective of the battery temperature T _B, but does not reduce the safety of the vehicle, would decrease the vehicle interior comfort (comfort degraded state).

Considering the effects shown in FIGS. 4 (d) to 4 (h), the phenomenon that most affects the safety of the vehicle is the effect on the traveling performance of FIG. 4 (d). Therefore, in the present embodiment, the battery temperature T _B is less than the second temperature T2, than the air conditioning function battery cooling function to improve cabin comfort with priority, in the battery temperature and the second temperature T2 or higher, the battery cooling The function is configured to give priority to the air conditioning function to ensure the safety of the vehicle.

Next, the processing of the vehicle cooling device will be described with reference to FIG. FIG. 5 is a flowchart showing a cooling process of the vehicle cooling device. The vehicle cooling device 1 repeatedly executes the cooling process shown in FIG. 5 at predetermined time intervals (for example, every 10 ms).

First, when the cooling process is started, the control unit 50, various temperature sensors, acquires vehicle information including the conditioned set S _AC from the detection value and the air-conditioning panel from the pressure sensor (step S1). Next, the control device 50 determines whether or not there is an air conditioning request based on the _{air conditioning setting S AC (step S2).} That is, when the air conditioning mode (cooling mode or heating mode) of the control device 50 is selected _{and the temperature difference between the target temperature T TGT} and the actual temperature T _CAB is equal to or greater than a predetermined value, there is an air conditioning request. judge.

When there is no air conditioning request (S2; No), the control device 50 stops the compressor 12 and fully closes the air conditioning valve 18 and the battery cooling valve 32 (step S6). Even when there is no air-conditioning command, when the battery temperature T _B is a predetermined temperature (first temperature T1) or higher, it may be executed as a separate process the process for the battery cooling.

On the other hand, when there is an air conditioning request (S2; Yes), the control device 50 determines whether or not there is a battery cooling request (step S3). Specifically, the control device 50 _{determines whether or not the required level indicated by the battery cooling request RC} C is "1", "2", or "3".

When the battery cooling request level is "0" (no battery cooling request) (S3; No), the control device 50 controls the air conditioning device 10 so as to satisfy the air conditioning request (step S7). _{Specifically, the control device 50 outputs the compressor required rotation speed R COM} so as to satisfy the air conditioning requirement, and operates the compressor 12 at a predetermined required rotation speed. Further, the control device 50 keeps the air conditioning valve 18 fully open and the battery cooling valve 32 fully closed. When there is no battery cooling requirements because the battery temperature T _B is low (less than the first temperature T1), the output allowable power P _L of the battery 4 is not limited.

On the other hand, when there is a battery cooling request (S3; Yes), the control device 50 determines whether or not the battery temperature is equal to or higher than the first temperature T1 and lower than the second temperature T2 (step S4). Specifically, the control device 50 determines whether or not the battery cooling request level is "1" (first battery cooling request).

When the battery cooling request level is "1" (first battery cooling request) (S4; No), the control device 50 controls the air conditioning device 10 and the battery cooling device 30 in the air conditioning priority mode (step S8). As described above, the driving power of the compressor 12, the maximum output P _MAX of the compressor 12 or less, and is limited below the residual power P _R.

Therefore, when the total electric power of the battery cooling power required to meet the air conditioning required power and the battery cooling requirements to meet the air conditioning requirements, the limit power (maximum power P _MAX, or the remaining power P _R) does not exceed the Both air conditioning requirements and battery cooling requirements can be met by limiting power. _{In this case, the control device 50 outputs the compressor required rotation speed R COM} so as to satisfy the air conditioning requirement and the battery cooling requirement, and operates the compressor 12 at a predetermined required rotation speed. Further, the control device 50 so as to satisfy the air conditioning requirement and the battery cooling requirement (that is, the flow ratio of the refrigerant of the cooling pipe 11a and the battery piping 31 becomes the power ratio of the air conditioning required power and the battery cooling required power. ), Adjust the valve opening of the air conditioning valve 18 and the battery cooling valve 32.

However, when the total power exceeds the power limit, the power limit is preferentially allocated to the air conditioning power over the battery cooling power. That is, if the required power for air conditioning is equal to or higher than the power limit, the power for air conditioning is set to the power limit and the power for cooling the battery is set to zero. At this time, the electric power P2com for cooling the battery 4 is not considered. If the required power for air conditioning is less than the required power for air conditioning, the power for air conditioning is set to the required power for air conditioning, and the power for cooling the battery is set to the usable power obtained by subtracting the required power for air conditioning from the limited power. When the usable power is equal to or less than a predetermined value, the battery cooling valve 32 may be fully closed with the battery cooling power set to zero instead of setting the battery cooling power to the usable power or less.

The control device 50 outputs the _{compressor required rotation speed R COM} so that the compressor 12 is operated by the total power of the air conditioning power and the battery cooling power. Further, the control device 50 opens the air conditioning valve 18 and the battery cooling valve 32 so that the flow ratio of the refrigerant between the cooling pipe 11a and the battery pipe 31 becomes the power ratio between the air conditioning power and the battery cooling power. Adjust the degree.

On the other hand, when the battery cooling request level is "2" or "3" (S4; Yes), the control device 50 further determines whether or not the battery cooling request level is "3" (step S5). When the battery cooling request level is "2" (second battery cooling request) (S5; No), the control device 50 controls the air conditioner 10 and the battery cooling device 30 in the second battery cooling priority mode (step S9). ).

When the second battery cooling priority mode is executed, the battery 4 cannot output the power P _{M IN} to the extent that the electric motor 3 can output a predetermined driving force due to the limitation of the output limit power PL. are _{(P L <P MIN + P2com} ). In this mode, the power P2com for cooling the battery 4 has the highest priority. _{Therefore, the control device 50 must limit the total power of the drive power P M} of the electric motor 3 and the drive power P 2 com of the compressor 12 to the output limit power P _L or less.

Controller 50, a battery cooling power is set to the drive power P2com, the output limit power currently available power obtained by subtracting the electric power supplied P _M of the P _L to the driving power P2com and the electric motor 3, the air-conditioning power assign. When the usable power becomes a negative value, the power supplied to the electric motor 3 _PM is limited, and the power for air conditioning becomes zero. If the usable power is a positive value, the air conditioning power is set to the smaller value of the usable power and the required air conditioning power.

The control device 50 outputs the _{compressor required rotation speed R COM} so that the compressor 12 is operated by the total power of the air conditioning power and the battery cooling power. Further, the control device 50 opens the air conditioning valve 18 and the battery cooling valve 32 so that the flow ratio of the refrigerant between the cooling pipe 11a and the battery pipe 31 becomes the power ratio between the air conditioning power and the battery cooling power. Adjust the degree. As described above, the control device 50 supplies the battery cooling device 30 with the amount of the refrigerant required for the battery cooling request among the refrigerants of the predetermined flow rate provided by the compressor 12 of the air conditioner 10, and supplies the refrigerant to the battery cooling device 30. The air conditioner 10 is controlled so as to perform air conditioning in the vehicle interior using the refrigerant left behind.

On the other hand, when the battery cooling request level is "3" (third battery cooling request) (S5; Yes), the control device 50 controls the air conditioner 10 and the battery cooling device 30 in the first battery cooling priority mode (S5; Yes). Step S10). In the first battery cooling priority mode, the control device 50 ignores the air conditioning requirement and controls so as to satisfy only the battery cooling requirement. When the first battery cooling priority mode is executed, the vehicle is in a non-running state (stopped). Therefore, the battery 4 does not need to supply electric power to the electric motor 3, and the compressor 12 can be operated if there is electric power that can be supplied.

In the first battery cooling priority mode, the control device 50 fully opens the battery cooling valve 32 and fully closes the air conditioning valve 18. In this way, the control device 50 supplies the battery cooling device 30 with the entire amount of the refrigerant having a predetermined flow rate provided by the compressor 12 of the air conditioner 10. At this time, if the power that can be supplied by the battery 4 is equal to or greater than the battery cooling required power, the control device 50 _{outputs the compressor required rotation speed R COM} so as to satisfy the battery cooling request, and rotates the compressor 12 at a predetermined required rotation speed. Operate by number. On the other hand, if the power that can be supplied by the battery 4 is less than the power required for cooling the battery, the control device 50 requests the compressor 12 to set the power for cooling the battery to the power that can be supplied and operate the compressor 12 with the power that can be supplied. Outputs the rotation speed R _COM.

Next, the operation of the vehicle cooling device 1 of the present embodiment will be described.
Vehicle refrigerator 1 of the present embodiment includes an electric motor 3 for generating a driving force of the vehicle, the battery 4 supplies electric power to the electric motor 3, a battery temperature sensor TS33 for detecting the temperature T _B of the battery 4, control an air conditioning unit 10 that performs air conditioning of the passenger compartment using a coolant, the battery cooling device 30 for cooling the battery 4 by using the refrigerant of the air conditioner 10, the air conditioner 10 based on the air-conditioning set S _AC by the driver of the vehicle while, when the detected temperature T _B of the battery 4 is the first temperature T1 or more predetermined generates a battery cooling requirements, controls the battery cooling device 30 to cool the battery 4 on the basis of the battery cooling demand and a control unit 50, a controller 50, there is air conditioning requirements and battery cooling requirements, and, at a second temperature below T2 for detecting the temperature T _B of the battery 4 is set to a temperature higher than the first temperature T1 In a certain case (S4; No), the first control process (S8) for controlling the air conditioner 10 and the battery cooling device 30 is executed with priority given to the air conditioning request over the cooling request, and there is an air conditioning request and a battery cooling request. and, if the detected temperature T _B of the battery 4 is the second temperature T2 or higher (S4; Yes), in favor of the cooling requirements than the air conditioning requirements, the second control process for controlling the air conditioner 10 and the battery cooling device 30 It is configured to execute (S9, S10).

With this configuration, in the present embodiment, in addition to the air-conditioning request by the occupant, if the battery cooling demand is generated (the battery temperature T _B is generated by the first temperature T1 or higher), the air conditioning requirements and the battery cooling demand It is necessary to supply the refrigerant of the air conditioner 10 so as to satisfy the requirements. Therefore, when the amount of refrigerant supplied is insufficient, it is necessary to distribute the refrigerant according to the air conditioning request and the battery cooling request. Therefore, in the present embodiment (specifically, lower than the second temperature T2) when the battery temperature T _B is in a relatively low temperature range, it is hard to affect the driving safety of the vehicle, the air-conditioning request by the occupant It can be prioritized to improve the comfort of the passenger compartment. On the other hand, in this embodiment, if the battery temperature T _B is in the relatively high temperature range (specifically, the second temperature T2 or higher), even if reduced cabin comfort, and the battery cooling request is prioritized , It is possible to prevent a decrease in the running safety of the vehicle.

Further, in the present embodiment, the control device 50, such that the output allowable power P _L of the battery 4 is lowered in accordance with the temperature rise of the battery 4, to limit the output allowable power P _L of the battery 4, the second temperature T2 the output allowable power P _L of the battery 4 in the second temperature T2 is, the electric motor 3 is set to be a predetermined minimum capable of generating a driving force of the power P _MIN.
With this configuration, in the present embodiment, if the battery temperature T _B is less than the second temperature T2, the battery 4 can supply power P _MIN of minimum to the electric motor 3. Thus, in this embodiment, if the battery temperature T _B is less than the second temperature T2, while giving priority to air conditioning request by the passenger for good cabin comfort, suppressing a decrease in the running safety of the vehicle be able to.

Further, in the present embodiment, in the second control process (S9), the control device 50 supplies the battery cooling device 30 with an amount of the refrigerant required for the battery cooling request among the refrigerants having a predetermined flow rate provided by the air conditioner 10. Then, the air conditioner 10 is controlled so as to air-condition the interior of the vehicle using the refrigerant left unsupplied to the battery cooling device 30.
With this configuration, in the present embodiment, when the battery temperature T _B is equal to or higher than the second temperature T2, since preferentially refrigerant in the battery cooling device 30 is supplied, is reliably cool the battery 4, the running safety of the vehicle Sex can be ensured.

Further, in the present embodiment, the control device 50, in the second control process (S10), if the detected temperature T _B of the battery 4 is a third temperature T3 or higher which is set to a temperature higher than the second temperature T2 ( S5; Yes), the entire amount of the refrigerant of the predetermined flow rate provided by the air conditioner 10 is supplied to the battery cooling device 30.
With this configuration, in the present embodiment, if the battery temperature T _B is the third temperature T3 or more, by using a further preference to all refrigerant battery cooling than air conditioning to the battery cooling, battery temperature T _B is increased It is possible to prevent the vehicle from becoming inoperable after passing.

Further, in the present embodiment, the battery cooling device 30 cools the battery 4 by direct heat exchange between the refrigerant and the battery 4.
With this configuration, in the present embodiment, the cooling heat of the refrigerant can be directly applied to the battery 4 without passing through an intermediate medium (water or the like) to cool the battery 4. Thereby, in the present embodiment, it is possible to prevent the occurrence of loss caused by heat exchange between the refrigerant and the intermediate medium and the increase in size of the apparatus.

Further, in the present embodiment, the control device 50 sets the air conditioning requirement larger as the temperature difference between _{the actual temperature T CAB in} the vehicle interior and the target temperature T T _{GT set by the occupant is larger.}
With this configuration, in the present embodiment, the air conditioning requirement can be appropriately set based on the temperature difference between _{the target temperature T TGT} and the actual temperature T _{CAB in the vehicle interior.}

1 Vehicle cooling device 3 Electric motor 4 Battery 10 Air conditioner 11a Cooling pipe 11b Heating pipe 12 Compressor 16 Outdoor heat exchanger 18 Air conditioner valve 19 Evaporator 30 Battery cooling device 32 Battery cooling valve 33 Heat exchanger 50 Control device 51 Air conditioning ECU
52 Battery ECU
53 PCM
54 Motor ECU
T1 first temperature T2 second temperature T3 third temperature T _B battery temperature TS33 battery temperature sensor

Claims (6)

It is a vehicle cooling device
An electric motor that generates the driving force of the vehicle and
A battery that supplies electric power to the electric motor and
A battery temperature sensor that detects the temperature of the battery and
An air conditioner that uses a refrigerant to air-condition the interior of the vehicle,
A battery cooling device that cools the battery using the refrigerant of the air conditioner, and
The air conditioner is controlled based on the air conditioning request by the occupant of the vehicle, and a battery cooling request is generated when the detected temperature of the battery is equal to or higher than a predetermined first temperature, and the battery is generated based on the battery cooling request. A control device that controls the battery cooling device so as to cool the battery.
The control device is
When there is the air conditioning request and the battery cooling request, and the detection temperature of the battery is less than the second temperature set to a temperature higher than the first temperature, the air conditioning request is prioritized over the battery cooling request. Then, the first control process for controlling the air conditioner and the battery cooling device is executed.
When there is the air conditioning request and the battery cooling request, and the detected temperature of the battery is the second temperature or higher, the air conditioning device and the battery cooling device give priority to the battery cooling request over the air conditioning request. A vehicle cooling device configured to perform a second control process to control the vehicle. The control device limits the output allowable power of the battery so that the output allowable power of the battery decreases as the temperature of the battery rises.
The vehicle according to claim 1, wherein the second temperature is set so that the allowable output power of the battery at the second temperature is the minimum power that the electric motor can generate a predetermined driving force. Cooling system. In the second control process, the control device takes out an amount of the refrigerant required for the battery cooling request from the refrigerant of a predetermined flow rate provided by the air conditioner, supplies the refrigerant to the battery cooling device, and supplies the refrigerant from the air conditioner. The vehicle cooling device according to claim 1 or 2, wherein the air conditioner is controlled so as to perform air conditioning in the vehicle interior using the refrigerant left unremoved. In the second control process, when the detection temperature of the battery is a third temperature or higher set to a temperature higher than the second temperature, the control device is used from the refrigerant having a predetermined flow rate provided by the air conditioner. The vehicle cooling device according to any one of claims 1 to 3, wherein the entire amount of the refrigerant is taken out and supplied to the battery cooling device. The vehicle cooling device according to any one of claims 1 to 4, wherein the battery cooling device cools the battery by directly exchanging heat between the refrigerant and the battery. The vehicle according to any one of claims 1 to 5, wherein the control device sets the air conditioning requirement larger as the temperature difference between the actual temperature in the vehicle interior and the target temperature set by the occupant is larger. For cooling device.

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