JP2018075922A - Vehicular air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular air conditioner which can continue an air conditioning operation while maintaining cooling performance of a radiator even when an error occurs in operation control of a refrigeration cycle.SOLUTION: A vehicular air conditioner 1 can execute air-conditioning in a cabin by a refrigeration cycle device 10 including a compressor 11, a second expansion valve 15b, an outdoor heat exchanger 16, and an indoor evaporator 18 and cooling of cooling object equipment by an engine cooling water circuit 70 and an inverter cooling water circuit 80. An engine radiator 71 and an inverter radiator 81 are arranged on a flow downstream side of outside air OA in the outdoor heat exchanger 16. A throttle opening of the second expansion valve 15b is controlled so that a supercooling degree SC on an outflow port side in the outdoor heat exchanger 16 may approach a target supercooling degree TSC during a cooling mode time. In the cooling mode, a rotational frequency range of the compressor 11 is changed from a normal rotational frequency range Rn to a fail time rotational frequency range Rf when an error occurs when specifying the target supercooling degree TSC.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicular air conditioner having a vapor compression refrigeration cycle and a radiator for cooling a device to be cooled.

  Conventionally, various inventions have been made as a vehicle air conditioner having a vapor compression refrigeration cycle. These vehicle air conditioners perform an air conditioning operation by appropriately controlling various components such as a compressor by an air conditioning control device. For this reason, in order to realize an appropriate air conditioning operation, it is necessary to detect the state of the refrigerant and the like with sensors and to control the operation of various components.

  Here, in the vehicle air conditioner, communication abnormality between the air conditioner control device and each component device or sensor failure may occur. If the air-conditioning operation is continued as it is under such a situation, the comfort in the passenger compartment is lowered, and it becomes a cause of failure of the constituent devices. For this reason, the invention regarding the vehicle air conditioner which can respond to generation | occurrence | production of an error is made | formed, for example, the invention described in patent document 1, 2 is known.

  The vehicle air conditioner system described in Patent Document 1 stops the operation of the compressor constituting the refrigeration cycle when an error occurs in the process of executing predetermined air conditioning control.

  On the other hand, a vehicle air conditioner described in Patent Document 2 includes an air conditioner ECU that outputs a drive control command based on an operation signal from a user and detection signals from various sensors, a refrigeration cycle, etc. by acquiring the drive control command. And an HVAC ECU that performs drive control of each constituent device.

  In this vehicle air conditioner, when a communication error occurs between the air conditioner ECU and the HVAC ECU, a drive control signal specified using a sensor or the like cannot be used for drive control of each component device. Therefore, window fogging or the like in the vehicle occurs. For this reason, when a communication error occurs, the vehicle air conditioner outputs a drive control command for the purpose of suppressing window fogging from the HVAC ECU without communicating with the air conditioner ECU.

JP-A-10-016545 JP 2014-108719 A

  However, since the vehicle air-conditioning system described in Patent Document 1 stops the operation of the compressor when an error occurs, the air-conditioning operation is also stopped. As a result, the vehicle air-conditioning system of Patent Document 1 deteriorates the comfort in the vehicle compartment as an error occurs.

  In addition, the vehicle air conditioner described in Patent Document 2 aims to prevent fogging in order to stop the air conditioning operation for the purpose of comfort in the passenger compartment and to ensure the sight of the occupant when a communication error occurs. It is configured to perform the following operation. For this reason, also in the vehicle air conditioner of Patent Document 2, the comfort in the passenger compartment deteriorates with the occurrence of a communication error.

  By the way, a radiator for cooling an engine, an inverter, and the like related to driving of the vehicle may be disposed in the vicinity of the refrigeration cycle in the vehicle air conditioner. When the cooling by the radiator is not sufficient, it becomes a failure factor of the traveling system of the vehicle.

  For this reason, it is necessary to pay attention to the influence of the radiator on the cooling of the traveling system of the vehicle when the vehicle air conditioner is arranged. This is because if an error occurs in the operation of the refrigeration cycle or the operation of the refrigeration cycle is stopped, the environment around the radiator changes greatly. Along with this, the cooling performance of the traveling system of the vehicle by the radiator may be lowered, which may cause a failure of the traveling system of the vehicle.

  In view of the above, the present invention provides a vehicle air conditioner that can continue air conditioning operation while maintaining the cooling performance of a radiator even when an error occurs in the operation control of the refrigeration cycle.

In order to achieve the object, an air conditioner for a vehicle according to claim 1,
A compressor (11) for compressing and discharging the refrigerant;
A radiator (16) that dissipates heat from the refrigerant discharged from the compressor;
A pressure reducing device (15b) capable of adjusting the degree of supercooling of the refrigerant on the outlet side of the radiator while reducing the pressure of the refrigerant radiated by the radiator,
A refrigeration cycle comprising: an evaporator (18) for exchanging heat between the refrigerant decompressed by the decompressor and air and evaporating the refrigerant;
Regarding the air flow introduced to the radiator (16), heat exchange is performed between the air and the heat medium that is disposed downstream of the radiator and absorbs heat from the cooling target equipment (ENG, INV) mounted on the vehicle. Radiators (71, 81)
An internal air temperature detector (51) for detecting the internal air temperature, which is the temperature in the passenger compartment,
An outside air temperature detecting unit (52) for detecting outside air temperature that is outside the passenger compartment;
An introduction air adjusting unit (33) for adjusting the air introduced as a heat exchange target in the evaporator using the inside air that is the air inside the vehicle interior and the outside air that is the air outside the vehicle interior;
A target supercooling degree specifying unit (40) for specifying a target supercooling degree using a detection result of the inside air temperature detecting part, a detection result of the outside air temperature detecting part, and an operation mode of the introduction air adjusting part;
A decompression control section (40c) for controlling the operation of the decompression device (15b);
A discharge capacity control unit (40a) for controlling the discharge capacity of the refrigerant in the compressor (11).

  The decompression control unit (40c) controls the decompression device (15b) so that the degree of supercooling approaches the target degree of supercooling specified by the target supercooling degree specifying unit.

  The discharge capacity control unit (40a) was able to normally specify the discharge capacity of the compressor (11) and the target supercooling degree normally when the target supercooling degree could not be normally specified by the target supercooling degree specifying unit. Reduce compared to the case.

  According to this vehicle air conditioner, it is possible to perform vehicle interior air conditioning using a refrigeration cycle and cooling of a cooling target device using a radiator. Here, when the target supercooling degree cannot be normally specified by the target supercooling degree specifying unit, for example, a detection error of the inside air temperature detecting unit or the outside air temperature detecting unit or an operation error of the introduction air adjusting unit There may be a case. In such a case, the target supercooling degree specifying unit may specify the target supercooling degree with a value smaller than the target supercooling degree specified during normal operation.

  In this vehicle air conditioner, the decompression control unit controls the decompression device so that the degree of supercooling on the outlet side of the radiator approaches the target degree of supercooling. Therefore, when a target subcooling degree smaller than normal is specified, the supercooling area on the outlet side of the radiator becomes smaller than normal, and the high-temperature gas area in the radiator increases. . Due to the decrease in the supercooling area and the increase in the gas area in the radiator, the temperature around the radiator increases. As a result, the temperature on the upstream side of the air flow with respect to the radiator rises, and there is a possibility that the cooling performance by the radiator is reduced.

  In this regard, according to this vehicle air conditioner, when the target supercooling degree cannot be normally specified by the target supercooling degree specifying unit, the discharge capacity control unit can normally specify the target supercooling degree. Compared with the case, in order to reduce the discharge capacity of the compressor, the temperature in the vicinity of the radiator can be made lower than the temperature necessary for maintaining the cooling performance in the radiator.

  That is, in this vehicle air conditioner, even if the target supercooling degree cannot be normally specified by the target supercooling degree specifying unit, the cooling by the radiator is not performed for a certain degree without stopping the compressor. A decrease in ability can be suppressed. That is, even when an error occurs in the target supercooling degree specifying unit, the air conditioning in the vehicle interior can be continued while maintaining the cooling performance of the cooling target device by the radiator for a certain degree.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in the embodiment described later.

1 is an overall configuration diagram of a vehicle air conditioner according to a first embodiment. It is a schematic diagram which shows the positional relationship of an outdoor heat exchanger, an engine radiator, and an inverter radiator. It is a block diagram which shows the control system of the vehicle air conditioner which concerns on 1st Embodiment. It is a flowchart of the control processing regarding the setting of the target supercooling degree in 1st Embodiment. It is a graph which shows the relationship between the target supercooling degree in 1st Embodiment, and external temperature. It is a flowchart of the control processing regarding the setting of the rotation speed range of the compressor in 1st Embodiment. It is a graph which shows the rotation speed range of the compressor at the time of the cooling operation which concerns on 1st Embodiment. It is a graph regarding the setting of the rotation speed upper limit at the time of fail safe setting which concerns on 2nd Embodiment. It is a graph regarding the setting of the rotation speed upper limit at the time of fail safe setting which concerns on 3rd Embodiment. It is a flowchart of the control processing regarding the setting of the rotation speed range of the compressor in 4th Embodiment.

(First embodiment)
Hereinafter, based on an embodiment (first embodiment) in which a vehicle air conditioner according to the present invention is applied to a vehicle air conditioner used to adjust a vehicle interior space to an appropriate temperature, with reference to the drawings. This will be described in detail. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

  In the first embodiment, the refrigeration cycle apparatus 10 is used to adjust various devices and vehicle interiors included in a vehicle to an appropriate temperature. That is, the refrigeration cycle apparatus 10 functions as an on-vehicle equipment temperature adjusting device and a vehicle air conditioner. The refrigeration cycle apparatus 10 according to the first embodiment is applied to a hybrid vehicle that obtains driving force for vehicle travel from an engine ENG (in other words, an internal combustion engine) and a travel electric motor.

  Further, the refrigeration cycle apparatus 10 is configured to be switchable to a heating mode refrigerant circuit, a dehumidifying heating mode refrigerant circuit, and a cooling mode refrigerant circuit. Here, in the vehicle air conditioner 1, the heating mode is an operation mode in which the blown air is heated and blown out into the passenger compartment. The dehumidifying and heating mode is an operation mode in which the blown air that has been cooled and dehumidified is reheated and blown out into the passenger compartment. The cooling mode is an operation mode in which the blown air is cooled and blown out into the passenger compartment.

  In FIG. 1, the refrigerant flow in the refrigerant circuit in the heating mode is indicated by black arrows, and the refrigerant flow in the refrigerant circuit in the dehumidifying heating mode is indicated by hatched arrows. Further, the flow of the refrigerant in the cooling mode refrigerant circuit is indicated by white arrows.

  The refrigeration cycle apparatus 10 employs an HFC refrigerant (specifically, R134a) as a refrigerant, and constitutes a vapor compression subcritical refrigeration cycle in which the high-pressure side refrigerant pressure Pd does not exceed the refrigerant critical pressure. ing. Of course, an HFO refrigerant (for example, R1234yf) or the like may be adopted as the refrigerant. Furthermore, the refrigerating machine oil for lubricating the compressor 11 is mixed in the refrigerant, and a part of the refrigerating machine oil circulates in the cycle together with the refrigerant.

  As shown in FIG. 1, the refrigeration cycle apparatus 10 includes a compressor 11, a first expansion valve 15a, a second expansion valve 15b, an outdoor heat exchanger 16, a check valve 17, an indoor evaporator 18, and an evaporation pressure adjusting valve 19. And an accumulator 20, a first on-off valve 21, and a second on-off valve 22.

  The compressor 11 sucks the refrigerant in the refrigeration cycle apparatus 10, compresses it, and discharges it. The compressor 11 is arrange | positioned in the vehicle bonnet. The compressor 11 is configured as an electric compressor that drives a fixed capacity type compression mechanism with a fixed discharge capacity by an electric motor. As this compression mechanism, various compression mechanisms such as a scroll-type compression mechanism and a vane-type compression mechanism can be employed.

  The operation (the number of rotations) of the electric motor constituting the compressor 11 is controlled by a control signal output from the air conditioning control device 40 described later. As this electric motor, either an AC motor or a DC motor may be adopted. And the refrigerant | coolant discharge capability of a compression mechanism is changed because the air-conditioning control apparatus 40 controls the rotation speed of an electric motor. Therefore, the electric motor constitutes the discharge capacity changing unit of the compression mechanism.

  The refrigerant inlet side of the indoor condenser 12 is connected to the discharge port of the compressor 11. The indoor condenser 12 functions as a heat exchanger for heating in the heating mode and the dehumidifying heating mode. That is, in the heating mode and the dehumidifying heating mode, the indoor condenser 12 exchanges heat between the high-temperature and high-pressure discharged refrigerant discharged from the compressor 11 and the blown air that has passed through the indoor evaporator 18 to be described later. Heat. The indoor condenser 12 is arrange | positioned in the casing 31 of the indoor air conditioning unit 30 mentioned later.

  One refrigerant inlet of the first three-way joint 13a is connected to the refrigerant outlet of the indoor condenser 12. A three-way joint such as the first three-way joint 13a functions as a branching part or a joining part in the refrigeration cycle apparatus 10.

  For example, in the first three-way joint 13a in the dehumidifying and heating mode, one of the three inlets and outlets is used as an inlet and the remaining two are used as outlets. Therefore, the first three-way joint 13a in the dehumidifying and heating mode functions as a branching portion that branches the flow of the refrigerant flowing in from one inflow port and outflows from the two outflow ports. These three-way joints may be formed by joining a plurality of pipes, or may be formed by providing a plurality of refrigerant passages in a metal block or a resin block.

  Furthermore, the refrigeration cycle apparatus 10 includes a second three-way joint 13b to a fourth three-way joint 13d, as will be described later. The basic configuration of the second three-way joint 13b to the fourth three-way joint 13d is the same as that of the first three-way joint 13a. For example, in the fourth three-way joint 13d in the dehumidifying and heating mode, two of the three inlets and outlets are used as inlets, and the remaining one is used as an outlet. Accordingly, the fourth three-way joint 13d in the dehumidifying and heating mode functions as a joining portion that joins the refrigerant that has flowed in from the two inlets and flows out from the one outlet.

  The first refrigerant passage 14a is connected to another inflow / outlet of the first three-way joint 13a. The first refrigerant passage 14 a guides the refrigerant that has flowed out of the indoor condenser 12 to the refrigerant inlet (that is, the inlet 16 a) side of the outdoor heat exchanger 16.

  The second refrigerant passage 14b is connected to still another inlet / outlet of the first three-way joint 13a. The second refrigerant passage 14b allows the refrigerant flowing out from the indoor condenser 12 to flow into the inlet side of the second expansion valve 15b (specifically, one of the third three-way joints 13c) disposed in the third refrigerant passage 14c described later. Inlet / outlet).

  A first expansion valve 15a is disposed in the first refrigerant passage 14a. The first expansion valve 15a decompresses the refrigerant that has flowed out of the indoor condenser 12 during the heating mode and the dehumidifying heating mode. The first expansion valve 15a is a variable throttle mechanism having a valve body configured to be able to change the throttle opening degree and an electric actuator composed of a stepping motor that changes the throttle opening degree of the valve body.

  Further, the first expansion valve 15a is configured as a variable throttle mechanism with a fully-open function that functions as a simple refrigerant passage with almost no refrigerant decompression effect by fully opening the throttle opening. The operation of the first expansion valve 15a is controlled by a control signal (control pulse) output from the air conditioning controller 40.

  The outlet side of the first expansion valve 15a is connected to the refrigerant inlet (that is, the inlet 16a) side of the outdoor heat exchanger 16, and is arranged on the vehicle front side in the vehicle bonnet. The outdoor heat exchanger 16 exchanges heat between the refrigerant flowing out of the first expansion valve 15a and the air outside the vehicle (that is, outside air OA) blown from a blower fan (not shown). The blower fan is an electric blower whose number of rotations (blowing capacity) is controlled by a control voltage output from the air conditioning control device 40.

  Specifically, the outdoor heat exchanger 16 functions as a heat absorber that absorbs heat from the outside air in the heating mode. In the cooling mode and the dehumidifying heating mode, the outdoor heat exchanger 16 functions as a radiator that radiates heat to the outside air OA.

  As shown in FIG. 2, the outdoor heat exchanger 16 has an inflow port 16a as a refrigerant inlet and an outflow port 16b as a refrigerant outlet. The inflow port 16a is disposed at the upper part of the outdoor heat exchanger 16, and is a portion into which the refrigerant that has flowed through the first refrigerant passage 14a flows. The outflow port 16b is arrange | positioned in the lower part of the outdoor heat exchanger 16, and is a part from which a refrigerant | coolant flows out toward the 2nd three-way coupling 13b.

  Then, as shown as a refrigerant flow R in FIG. 2, when the refrigerant flows into the outdoor heat exchanger 16 through the inflow port 16a, the refrigerant flows along the flat tube constituting the outdoor heat exchanger 16, and flows into the outflow port 16b. Out to the outside. At this time, in the outdoor heat exchanger 16, heat exchange is performed between the refrigerant flowing in the flat tube and the outside air OA flowing from the front to the rear of the vehicle.

  One inlet / outlet of the second three-way joint 13b is connected to the outlet 16b (that is, the refrigerant outlet) side of the outdoor heat exchanger 16. A third refrigerant passage 14c is connected to another inflow / outlet of the second three-way joint 13b. The third refrigerant passage 14 c guides the refrigerant that has flowed out of the outdoor heat exchanger 16 to the refrigerant inlet side of the indoor evaporator 18.

  The fourth refrigerant passage 14d is connected to still another inflow / outlet of the second three-way joint 13b. The fourth refrigerant passage 14d guides the refrigerant that has flowed out of the outdoor heat exchanger 16 to the inlet side of the accumulator 20, which will be described later (specifically, one inlet / outlet of the fourth three-way joint 13d).

  In the third refrigerant passage 14c, a check valve 17, a third three-way joint 13c, and a second expansion valve 15b are arranged in this order with respect to the refrigerant flow. The check valve 17 only allows the refrigerant to flow from the second three-way joint 13b side to the indoor evaporator 18 side. The second refrigerant passage 14b described above is connected to the third three-way joint 13c.

  The second expansion valve 15 b decompresses the refrigerant that flows out of the outdoor heat exchanger 16 and flows into the indoor evaporator 18. The second expansion valve 15b functions as a pressure reducing device in the present invention. The basic configuration of the second expansion valve 15b is the same as that of the first expansion valve 15a, and is an electric motor comprising a valve body configured to be able to change the throttle opening and a stepping motor that changes the throttle opening of the valve body. And an actuator. Further, the second expansion valve 15b is configured by a variable throttle mechanism with a fully-closed function that closes the refrigerant passage when the throttle opening is fully closed.

  Therefore, in the refrigeration cycle apparatus 10 according to the first embodiment, the refrigerant circuit can be switched by fully closing the second expansion valve 15b and closing the third refrigerant passage 14c. In other words, the second expansion valve 15b functions as a refrigerant decompression device and also has a function as a refrigerant circuit switching device that switches a refrigerant circuit of the refrigerant circulating in the cycle.

  The indoor evaporator 18 functions as a cooling heat exchanger during the cooling mode and the dehumidifying heating mode. That is, the indoor evaporator 18 exchanges heat between the refrigerant flowing out of the second expansion valve 15b and the blown air before passing through the indoor condenser 12 in the cooling mode and the dehumidifying heating mode. In the indoor evaporator 18, the blown air is cooled by evaporating the refrigerant decompressed by the second expansion valve 15 b and exerting an endothermic action. The indoor evaporator 18 is arranged in the casing 31 of the indoor air conditioning unit 30 on the upstream side of the air flow of the indoor condenser 12.

  The refrigerant outlet of the indoor evaporator 18 is connected to the inlet side of the evaporation pressure adjusting valve 19. The evaporation pressure adjusting valve 19 has a function of adjusting the refrigerant evaporation pressure (that is, the low-pressure side refrigerant pressure) in the indoor evaporator 18 to be equal to or higher than the frosting suppression pressure in order to suppress frost formation (frost) of the indoor evaporator 18. Fulfill. In other words, the evaporation pressure adjusting valve 19 functions to adjust the refrigerant evaporation temperature Te in the indoor evaporator 18 to be equal to or higher than a predetermined frosting suppression temperature.

  As shown in FIG. 1, a fourth three-way joint 13 d is connected to the outlet side of the evaporation pressure adjusting valve 19. As described above, the fourth refrigerant passage 14d is connected to the other inlet / outlet of the fourth three-way joint 13d. And the inlet side of the accumulator 20 is connected to another inflow / outlet of the fourth three-way joint 13d.

  The accumulator 20 is a gas-liquid separator that separates the gas-liquid of the refrigerant that has flowed into the accumulator and stores excess refrigerant in the cycle. The suction port side of the compressor 11 is connected to the gas-phase refrigerant outlet of the accumulator 20. Therefore, the accumulator 20 functions to prevent liquid phase refrigerant from being sucked into the compressor 11 and prevent liquid compression in the compressor 11.

  A first on-off valve 21 is disposed in the fourth refrigerant passage 14d that connects the second three-way joint 13b and the fourth three-way joint 13d. The first on-off valve 21 is constituted by an electromagnetic valve. The first on-off valve 21 functions as a refrigerant circuit switching device that switches the refrigerant circuit by opening and closing the fourth refrigerant passage 14d. The operation of the first on-off valve 21 is controlled by a control signal output from the air conditioning control device 40.

  Similarly, the 2nd on-off valve 22 is arrange | positioned in the 2nd refrigerant path 14b which connects the 1st three-way coupling 13a and the 3rd three-way coupling 13c. Similar to the first on-off valve 21, the second on-off valve 22 is configured by an electromagnetic valve. The second on-off valve 22 functions as a refrigerant circuit switching device that switches the refrigerant circuit by opening and closing the second refrigerant passage 14b.

  Next, the indoor air-conditioning unit 30 which comprises the vehicle air conditioner 1 with the refrigeration cycle apparatus 10 is demonstrated. The indoor air conditioning unit 30 is for blowing out the blown air whose temperature has been adjusted by the refrigeration cycle apparatus 10 into the vehicle interior. The indoor air conditioning unit 30 is disposed inside the instrument panel (instrument panel) at the forefront of the vehicle interior.

  As shown in FIG. 1, the indoor air conditioning unit 30 is configured by housing a blower 32, an indoor evaporator 18, an indoor condenser 12, and the like in a casing 31 that forms an outer shell thereof. The casing 31 forms an air passage for blown air blown into the vehicle interior. The casing 31 is formed of a resin (for example, polypropylene) having a certain degree of elasticity and excellent in strength.

  An inside / outside air switching device 33 is disposed on the most upstream side of the blown air flow in the casing 31. The inside / outside air switching device 33 switches and introduces inside air (vehicle compartment air) and outside air (vehicle compartment outside air) into the casing 31.

  Specifically, the inside / outside air switching device 33 continuously adjusts the opening area of the inside air introduction port for introducing the inside air into the casing 31 and the outside air introduction port for introducing the outside air by the inside / outside air switching door, The air volume ratio between the air volume and the outside air volume can be continuously changed. The inside / outside air switching door is driven by an electric actuator for the inside / outside air switching door. The operation of the electric actuator is controlled by a control signal output from the air conditioning controller 40. Therefore, the inside / outside air switching device 33 functions as an introduction air adjusting unit in the present invention.

  A blower 32 is disposed on the downstream side of the blown air flow of the inside / outside air switching device 33. The blower 32 blows air sucked through the inside / outside air switching device 33 toward the vehicle interior. The blower 32 is an electric blower that drives a centrifugal multiblade fan (sirocco fan) with an electric motor. The number of rotations of the centrifugal multiblade fan in the blower 32 (the amount of blown air) is controlled by a control voltage output from the air conditioning controller 40.

  On the downstream side of the blower air flow of the blower 32, the indoor evaporator 18 and the indoor condenser 12 are arranged in this order with respect to the blown air flow. In other words, the indoor evaporator 18 is disposed on the upstream side of the blown air flow with respect to the indoor condenser 12.

  A cold air bypass passage 35 is formed in the casing 31. The cold air bypass passage 35 is a passage for allowing the blown air that has passed through the indoor evaporator 18 to flow downstream by bypassing the indoor condenser 12.

  An air mix door 34 is arranged on the downstream side of the blower air flow of the indoor evaporator 18 and on the upstream side of the blower air flow of the indoor condenser 12. The air mix door 34 is used when adjusting the ratio of the amount of air passing through the indoor condenser 12 in the blown air after passing through the indoor evaporator 18. Therefore, the vehicle air conditioner 1 sets the cold air bypass passage 35 to a fully open position, and fully closes the flow path of the blown air toward the indoor condenser 12 by the air mix door 34, whereby the heat exchange amount in the indoor condenser 12 is reached. Can be minimized.

  A mixing space is provided on the downstream side of the blower air flow of the indoor condenser 12. In the mixing space, the blown air heated by the indoor condenser 12 and the blown air that has passed through the cold air bypass passage 35 and is not heated by the indoor condenser 12 are mixed. Further, a plurality of opening holes are arranged in the most downstream portion of the blown air flow of the casing 31. The blown air (air conditioned air) mixed in the mixing space is blown out into the vehicle interior, which is the air conditioning target space, through these opening holes.

  Specifically, a face opening hole, a foot opening hole, and a defroster opening hole (all not shown) are provided as these opening holes. The face opening hole is an opening hole for blowing air conditioned air toward the upper body of the passenger in the passenger compartment. The foot opening hole is an opening hole for blowing air-conditioned air toward the passenger's feet. The defroster opening hole is an opening hole for blowing conditioned air toward the inner side surface of the vehicle front window glass.

  Further, the air flow downstream of the face opening hole, the foot opening hole, and the defroster opening hole is respectively connected to the face air outlet, the foot air outlet, and the defroster air outlet ( Neither is shown). Therefore, the air mix door 34 adjusts the air volume ratio between the air volume that passes through the indoor condenser 12 and the air volume that passes through the cold air bypass passage 35, thereby adjusting the temperature of the conditioned air mixed in the mixing space. The temperature of the conditioned air blown from each outlet into the passenger compartment is adjusted.

  That is, the air mix door 34 functions as a temperature adjustment unit that adjusts the temperature of the conditioned air blown into the vehicle interior. The air mix door 34 is driven by an electric actuator for driving the air mix door. The operation of the electric actuator is controlled by a control signal output from the air conditioning controller 40.

  Further, on the upstream side of the air flow of the face opening hole, foot opening hole, and defroster opening hole, a face door for adjusting the opening area of the face opening hole, a foot door for adjusting the opening area of the foot opening hole, and a defroster opening, respectively. A defroster door (both not shown) for adjusting the opening area of the hole is disposed.

  These face doors, foot doors, and defroster doors constitute an outlet mode switching door that switches the outlet mode. The face door, the foot door, and the defroster door are connected to an electric actuator for driving the air outlet mode door via a link mechanism or the like, and are rotated in conjunction with each other. The operation of this electric actuator is also controlled by a control signal output from the air conditioning controller 40.

  Specific examples of the outlet mode switched by the outlet mode switching door include a face mode, a bi-level mode, and a foot mode.

  The face mode is an air outlet mode in which the face air outlet is fully opened and air is blown from the face air outlet toward the upper body of the passenger in the passenger compartment. The bi-level mode is an air outlet mode in which both the face air outlet and the foot air outlet are opened and air is blown toward the upper body and the feet of the passengers in the passenger compartment. The foot mode is an air outlet mode in which the foot air outlet is fully opened and blown air is blown from the foot air outlet toward the feet of the passengers in the passenger compartment.

  Furthermore, the occupant can also set the defroster mode by manually operating a blow mode switching switch provided on the operation panel 60. The defroster mode is a blowout port mode in which the defroster blowout port is fully opened and air is blown from the defroster blowout port to the inner surface of the vehicle front window glass.

  The engine coolant circuit 70 is a circuit that circulates engine coolant, which is a heat medium, in order to cool the engine ENG mounted on the vehicle. As shown in FIG. 1, an engine radiator 71, which is a heat exchanger, And a cooling water pump (not shown).

  The engine radiator 71 is a heat exchanger that exchanges heat between engine coolant, which is a heat medium circulating in the engine coolant circuit 70, and outside air. As shown in FIG. 2, the engine radiator 71 is arranged at a distance from the outdoor heat exchanger 16 on the downstream side with respect to the flow of the outside air OA introduced into the outdoor heat exchanger 16.

  More specifically, the engine radiator 71 is disposed so as to occupy an upper portion including the inlet 16a of the outdoor heat exchanger 16 on the downstream side of the flow of the outside air OA. Therefore, the engine radiator 71 radiates the heat of the engine cooling water to the outside air OA that has exchanged heat with the refrigerant in the outdoor heat exchanger 16. The cooling water pump is an electric heat medium pump that sucks and discharges engine cooling water.

  Therefore, the engine coolant circuit 70 circulates the engine coolant in the circulation passage including the engine ENG and the engine radiator 71 by driving the coolant pump, and exchanges heat between the engine ENG and the engine radiator 71. That is, the engine coolant circuit 70 can absorb the exhaust heat of the engine ENG with the engine coolant, and can radiate this heat with the engine radiator 71.

  As the engine cooling water, a liquid containing at least ethylene glycol, dimethylpolysiloxane or nanofluid, or an antifreeze liquid can be used, but an appropriate one is used according to the temperature condition of the engine ENG which is a cooling target device. ing.

  The inverter cooling water circuit 80 is a circuit that circulates the inverter cooling water that is a heat medium in order to cool the cooling target device including the inverter INV that is mounted on the vehicle, and an inverter radiator 81 that is a heat exchanger, Not have a cooling water pump.

  The inverter INV is a power converter that converts DC power supplied from the battery into AC power and outputs the AC power to the traveling motor. The inverter INV is one of the devices to be cooled that is cooled by the inverter cooling water circuit 80. The cooling target device arranged in the inverter cooling water circuit 80 is not limited to the inverter INV, and various cooling target devices may be arranged in the inverter cooling water circuit 80.

  The inverter radiator 81 is a heat exchanger that exchanges heat between the inverter cooling water, which is a heat medium circulating in the inverter cooling water circuit 80, and the outside air. As shown in FIG. 2, similarly to the engine radiator 71, the inverter radiator 81 is spaced downstream from the outdoor heat exchanger 16 with respect to the flow of the outside air OA introduced into the outdoor heat exchanger 16. Are arranged.

  More specifically, the inverter radiator 81 is disposed so as to occupy a lower portion including the outlet 16 b of the outdoor heat exchanger 16 on the downstream side of the flow of the outside air OA, and is positioned below the engine radiator 71. doing. Therefore, the inverter radiator 81 radiates the heat of the inverter cooling water to the outside air OA that has exchanged heat with the refrigerant in the outdoor heat exchanger 16.

  That is, since the inverter radiator 81 is arranged downstream of the flow of the outside air OA with respect to the supercooling region formed in the outdoor heat exchanger 16, the heat of the inverter cooling water is more efficiently transferred to the outside air OA. It can dissipate heat. The cooling water pump is an electric heat medium pump that sucks and discharges inverter cooling water.

  Accordingly, the inverter cooling water circuit 80 circulates the inverter cooling water in the circulation flow path including the inverter INV and the inverter radiator 81 by driving the cooling water pump, and causes the inverter INV and the inverter radiator 81 to exchange heat. That is, the inverter cooling water circuit 80 can absorb the exhaust heat of the inverter INV with the inverter cooling water and dissipate this heat with the inverter radiator 81.

  As the inverter cooling water, a liquid containing ethylene glycol or an antifreeze liquid can be used, but an appropriate one is used according to the temperature condition of the cooling target equipment including the inverter INV.

  Next, the control system of the vehicle air conditioner 1 will be described with reference to FIG. The vehicle air conditioner 1 has an air conditioning control device 40 for controlling the components of the refrigeration cycle apparatus 10 and the indoor air conditioning unit 30.

  The air conditioning control device 40 includes a known microcomputer including a CPU, a ROM, a RAM, and the like and peripheral circuits thereof. The air conditioning control device 40 performs various calculations and processes based on the control program stored in the ROM, so that the compressor 11, the first expansion valve 15a, and the second expansion valve 15b connected to the output side. The operation of air conditioning control devices such as the first on-off valve 21, the second on-off valve 22, the blower 32, and the inside / outside air switching device 33 is controlled.

  In addition, a detection signal of a sensor group for air conditioning control is input to the input side of the air conditioning control device 40. As shown in FIG. 3, the air temperature control sensor group includes an inside air temperature sensor 51, an outside air temperature sensor 52, a solar radiation sensor 53, a discharge temperature sensor 54, a high pressure side pressure sensor 55, an evaporator temperature sensor 56, and a low pressure side pressure. A sensor 57, a refrigerant temperature sensor 58, and the like are included.

  The inside air temperature sensor 51 is an inside air temperature detecting unit that detects a vehicle interior temperature (inside air temperature) Tr. The outside air temperature sensor 52 is an outside air temperature detecting unit that detects a vehicle compartment outside temperature (outside air temperature) Tam. The solar radiation sensor 53 is a solar radiation amount detection unit that detects the solar radiation amount As irradiated into the vehicle interior. The discharge temperature sensor 54 is a discharge temperature detection unit that detects the discharge refrigerant temperature Td of the refrigerant discharged from the compressor 11.

  The high pressure side pressure sensor 55 is a high pressure side pressure detector that detects the outlet side refrigerant pressure (high pressure side refrigerant pressure) Pd of the indoor condenser 12. The evaporator temperature sensor 56 is an evaporator temperature detector that detects a refrigerant evaporation temperature (evaporator temperature) Te in the indoor evaporator 18. The evaporator temperature sensor 56 detects the heat exchange fin temperature of the indoor evaporator 18. Here, as the evaporator temperature sensor 56, a temperature detection unit that detects the temperature of other parts of the indoor evaporator 18 may be employed, or a temperature that directly detects the temperature of the refrigerant itself flowing through the indoor evaporator 18. You may employ | adopt a detection part.

  The low-pressure sensor 57 is a low-pressure detector that detects the refrigerant pressure on the low-pressure side of the refrigeration cycle, and detects the refrigerant pressure on the inlet side of the compressor 11 as the low-pressure refrigerant pressure Ps. The refrigerant temperature sensor 58 is a detection unit that detects the temperature of the refrigerant flowing out from the outlet 16b of the outdoor heat exchanger 16.

  An engine cooling water temperature sensor 72 of the engine cooling water circuit 70 and an inverter cooling water temperature sensor 82 of the inverter cooling water circuit 80 are connected to the input side of the air conditioning control device 40, respectively.

  The engine coolant temperature sensor 72 is arranged in a range from the outlet side on the engine ENG side to the inlet side of the engine radiator 71 in the circulation flow path of the engine coolant circuit 70, and determines the temperature of the engine coolant. To detect. That is, the engine coolant temperature sensor 72 is an example of a heat medium temperature detection unit in the present invention. The air conditioning control device 40 can estimate the amount of heat absorbed by the engine coolant from the engine ENG.

  Further, the inverter cooling water temperature sensor 82 is disposed in the range from the outlet on the inverter INV side to the inlet side of the inverter radiator 81 in the circulation flow path of the inverter cooling water circuit 80, and the temperature of the inverter cooling water is determined. (Hereinafter, inverter cooling water temperature TWhv) is detected. That is, the inverter cooling water temperature sensor 82 is an example of a heat medium temperature detecting unit according to the present invention. The air conditioning control device 40 can estimate the amount of heat absorbed by the inverter cooling water from the inverter INV.

  Furthermore, an operation panel 60 disposed near the instrument panel in the front part of the vehicle interior is connected to the input side of the air conditioning control device 40. Accordingly, operation signals from various air conditioning operation switches provided on the operation panel 60 are input to the air conditioning control device 40.

  Specific examples of the various air conditioning operation switches provided on the operation panel 60 include an auto switch, a cooling switch (A / C switch), an air volume setting switch, a temperature setting switch, and a blowing mode switching switch.

  The auto switch is an input unit for setting or canceling the automatic control operation of the vehicle air conditioner 1. The cooling switch is an input unit for requesting cooling of the passenger compartment. The air volume setting switch is an input unit for manually setting the air volume of the blower 32. The temperature setting switch is an input unit for setting a vehicle interior set temperature Tset that is a target temperature in the vehicle interior. The blowing mode changeover switch is an input unit for manually setting the blowing mode.

  A vehicle control device 90 is connected to the input side of the air conditioning control device 40. The vehicle control device 90 is responsible for various controls related to the traveling of the vehicle on which the vehicle air conditioner 1 is mounted. For example, when the cooling load of the engine ENG by the engine cooling water circuit 70 and the cooling load of the inverter INV by the inverter cooling water circuit 80 are excessive, the vehicle control device 90 requests the change of the control content of the air conditioning operation. A control change signal is output to the air conditioning controller 40.

  The air-conditioning control device 40 is configured integrally with a control unit (in other words, a control device) that controls various air-conditioning control devices connected to the output side thereof. The structure (hardware and software) to control comprises the control part which controls the action | operation of each air-conditioning control apparatus.

  For example, the structure which controls the action | operation of the compressor 11 among the air-conditioning control apparatuses 40 comprises the discharge capacity control part 40a. Moreover, the structure which controls the action | operation of the 1st on-off valve 21, the 2nd on-off valve 22, etc. which are refrigerant circuit switching apparatuses among the air-conditioning control apparatuses 40 comprises the refrigerant circuit control part 40b.

  Moreover, the structure which controls the action | operation of the 1st expansion valve 15a and the 2nd expansion valve 15b which are pressure reduction apparatuses among the air-conditioning control apparatuses 40 comprises the pressure reduction control part 40c. Of course, the discharge capacity control unit 40a, the refrigerant circuit control unit 40b, the decompression control unit 40c, and the like may be configured as separate control units for the air conditioning control device 40.

  Then, the action | operation of the vehicle air conditioner 1 which concerns on 1st Embodiment is demonstrated. As described above, the vehicle air conditioner 1 can switch between the heating mode, the dehumidifying heating mode, and the cooling mode. And switching of each of these operation modes is performed by running an air-conditioning control program. This air conditioning control program is executed when the auto switch of the operation panel 60 is turned on.

In the main routine of the air conditioning control program, the detection signals of the air conditioning control sensor group and the operation signals from various air conditioning operation switches are read. Then, based on the read detection signal and operation signal values, a target blowing temperature TAO, which is a target temperature of the blowing air blown into the vehicle interior, is calculated based on the following formula F1.
TAO = Kset × Tset−Kr × Tr−Kam × Tam−Ks × As + C (F1)
Here, Tset is the vehicle interior set temperature set by the temperature setting switch, Tr is the vehicle interior temperature (internal air temperature) detected by the internal air temperature sensor 51, Tam is the outside air temperature detected by the outside air temperature sensor 52, and As is This is the amount of solar radiation detected by the solar radiation sensor 53. Kset, Kr, Kam, Ks are control gains, and C is a correction constant.

  Further, in the state where the cooling switch of the operation panel 60 is turned on, when the target blowing temperature TAO is lower than the predetermined cooling reference temperature α, the operation in the cooling mode is executed. In addition, when the cooling switch of the operation panel 60 is turned on and the target blowing temperature TAO is equal to or higher than the cooling reference temperature α, the operation in the dehumidifying heating mode is executed. Further, when the cooling switch is not turned on, the operation in the heating mode is executed.

  With this air conditioning control program, the cooling mode is executed mainly when the outside air temperature is relatively high, such as in summer. The dehumidifying heating mode is executed mainly in the spring or autumn. Furthermore, the heating mode can be executed mainly at low outdoor temperatures in winter.

  Further, in the air conditioning control program, the operating states of various control target devices are determined according to each operation mode. And the control signal according to the determined operating state, a control voltage, etc. are output to various control object apparatus. Thereafter, in the air conditioning control program, until the operation of the vehicle air conditioner 1 is requested to stop, reading of the detection signal and the operation signal at every predetermined control cycle → determination of the operation mode → determination of the operation state of various control target devices -> Control routines such as control voltage and control signal output are repeated. Below, each operation mode is demonstrated.

(A) Heating mode In the heating mode, the air conditioning control device 40 opens the first on-off valve 21 and closes the second on-off valve 22. Further, the first expansion valve 15a is in a throttle state that exerts a pressure reducing action, and the second expansion valve 15b is in a fully closed state.

  Thereby, in the heating mode, as indicated by the black arrow in FIG. 1, the compressor 11 → the indoor condenser 12 → the first expansion valve 15 a → the outdoor heat exchanger 16 → (the first on-off valve 21 →) the accumulator 20 → A vapor compression refrigeration cycle in which refrigerant is circulated in the order of the compressor 11 is configured.

  With this cycle configuration, the air conditioning control device 40 controls the operation of the compressor 11 so that the refrigerant flowing into the indoor condenser 12 reaches the target condenser temperature TCO. The target condenser temperature TCO is determined so as to increase as the target blowing temperature TAO increases. Further, the air conditioning control device 40 controls the operation of the first expansion valve 15a based on the pressure of the refrigerant flowing into the first expansion valve 15a so that the COP of the cycle approaches the maximum value. Further, the air conditioning control device 40 displaces the air mix door so that the cold air bypass passage 35 is fully closed, and fully opens the ventilation path on the indoor condenser 12 side.

  In the refrigeration cycle apparatus 10 in the heating mode, the indoor condenser 12 functions as a radiator and the outdoor heat exchanger 16 functions as an evaporator. The heat absorbed from the outside air when the refrigerant evaporates in the outdoor heat exchanger 16 is radiated to the blown air in the indoor condenser 12. Thereby, blowing air can be heated.

  Therefore, in the heating mode, the vehicle interior can be heated by blowing the blown air heated by the indoor condenser 12 into the vehicle interior.

(B) Dehumidification heating mode In the dehumidification heating mode, the air conditioning control device 40 opens the first on-off valve 21 and the second on-off valve 22, and puts the first expansion valve 15a and the second expansion valve 15b into the throttle state.

  Thus, in the dehumidifying heating mode, as indicated by the hatched arrows in FIG. 1, the compressor 11, the indoor condenser 12, the first expansion valve 15a, the outdoor heat exchanger 16, and the (first on-off valve 21) accumulator. The refrigerant is circulated in the order of 20 → compressor 11, and compressor 11 → indoor condenser 12 → (second on-off valve 22 →) second expansion valve 15 b → indoor evaporator 18 → evaporation pressure adjusting valve 19 → accumulator 20 → A vapor compression refrigeration cycle in which refrigerant is circulated in the order of the compressor 11 is configured.

  That is, in this dehumidifying heating mode, the flow of the refrigerant flowing out from the indoor condenser 12 is branched by the first three-way joint 13a, and one of the branched refrigerants is first expanded valve 15a → outdoor heat exchanger 16 → compressor. 11, and the other branched refrigerant is switched to the refrigerant circuit that flows in the order of the second expansion valve 15 b → the indoor evaporator 18 → the evaporation pressure regulating valve 19 → the compressor 11.

  With this cycle configuration, the air conditioning controller 40 controls the operation of the compressor 11 so that the blown air blown out from the indoor evaporator 18 becomes the target evaporator temperature TEO. The target evaporator temperature TEO is determined so as to decrease as the target outlet temperature TAO decreases. The target evaporator temperature TEO is determined within a range in which frost formation of the indoor evaporator 18 can be suppressed.

  The air conditioning control device 40 controls the operation of the first expansion valve 15a and the second expansion valve 15b so that the COP of the cycle approaches the maximum value based on the pressure of the refrigerant flowing into the first expansion valve 15a. At this time, the air-conditioning control device 40 decreases the throttle opening of the first expansion valve 15a and increases the throttle opening of the second expansion valve 15b as the target blowing temperature TAO increases. Further, the air conditioning control device 40 displaces the air mix door so that the cold air bypass passage 35 is fully closed, and fully opens the ventilation path on the indoor condenser 12 side.

  In this dehumidifying heating mode, the indoor condenser 12 functions as a radiator, and the outdoor heat exchanger 16 and the indoor evaporator 18 function as an evaporator. For this reason, the refrigerant | coolant saturation temperature of the outdoor heat exchanger 16 can be lowered | hung with the raise of the target blowing temperature TAO, and the heat absorption amount of the refrigerant | coolant in the outdoor heat exchanger 16 can be increased. Thereby, the thermal radiation amount of the refrigerant | coolant in the indoor condenser 12 can be increased, and a heating capability can be improved.

  Therefore, in this dehumidifying and heating mode, the dehumidifying and heating in the vehicle interior can be performed by reheating the blown air that has been cooled and dehumidified by the indoor evaporator 18 and blown out into the vehicle interior by the indoor condenser 12. it can. Further, since the saturation temperature (evaporation temperature) of the refrigerant in the outdoor heat exchanger 16 can be made lower than the saturation temperature (evaporation temperature) of the refrigerant in the indoor evaporator 18, the heating capacity of the blown air in the dehumidifying heating mode can be improved. Can be increased.

(C) Cooling Mode In the cooling mode, the air conditioning control device 40 closes the first on-off valve 21 and the second on-off valve 22. Moreover, the air-conditioning control apparatus 40 makes the 1st expansion valve 15a a full open state, and makes the 2nd expansion valve 15b a throttling state.

  Thereby, in the cooling mode, as indicated by the white arrow in FIG. 1, the compressor 11 → (the indoor condenser 12 → the first expansion valve 15a →) the outdoor heat exchanger 16 → (the check valve 17 →) the second A vapor compression refrigeration cycle in which the refrigerant is circulated in the order of the expansion valve 15b → the indoor evaporator 18 → the evaporation pressure adjusting valve 19 → the accumulator 20 → the compressor 11 is configured.

  With this cycle configuration, the air-conditioning control device 40 normally controls the operation of the compressor 11 so that the blown air blown out from the indoor evaporator 18 becomes the target evaporator temperature TEO. The target evaporator temperature TEO is determined so as to decrease as the target outlet temperature TAO decreases. The target evaporator temperature TEO is determined within a range in which frost formation of the indoor evaporator 18 can be suppressed. Further, the air conditioning control device 40 displaces the air mix door 34 so that the cold air bypass passage 35 is fully opened, and fully closes the ventilation path on the indoor condenser 12 side.

  And the air-conditioning control apparatus 40 controls the action | operation of the 2nd expansion valve 15b so that the supercooling degree SC of the refrigerant | coolant in the outflow port 16b side of the outdoor heat exchanger 16 may approach the target supercooling degree TSC. The air-conditioning control device 40 uses the outdoor heat exchanger 16 based on the high-pressure side refrigerant pressure Pd detected by the high-pressure side pressure sensor 55, the refrigerant temperature detected by the refrigerant temperature sensor 58, and the physical properties of the refrigerant circulating in the cycle. The current supercooling degree SC at is calculated.

  The air conditioning control device 40 controls the throttle opening of the second expansion valve 15b so that the calculated supercooling degree SC approaches the target supercooling degree TSC. This point will be described in detail later.

  In the refrigeration cycle apparatus 10 in the cooling mode, the outdoor heat exchanger 16 functions as a radiator, and the indoor evaporator 18 functions as an evaporator. Then, the heat absorbed from the blown air when the refrigerant evaporates in the indoor evaporator 18 is radiated to the outside air in the outdoor heat exchanger 16. Thereby, blowing air can be cooled.

  Therefore, in the cooling mode, the vehicle interior can be cooled by blowing the blown air cooled by the indoor evaporator 18 into the vehicle interior.

  Next, control processing relating to setting of the target subcooling degree in the vehicle air conditioner 1 will be described with reference to the drawings. As described above, when the vehicle air conditioner 1 is in the cooling mode, the air conditioning control device 40 sets the second expansion valve so that the degree of supercooling SC on the outlet side of the outdoor heat exchanger 16 approaches the target degree of supercooling TSC. The throttle opening of 15b is controlled.

  The flowchart shown in FIG. 4 is repeatedly executed while the air conditioning operation of the vehicle air conditioner 1 is being executed by the air conditioning control device 40 when setting the target supercooling degree TSC.

  In step S1, it is determined whether or not the operation mode is a cooling mode. If the current operation mode is the cooling mode, the process proceeds to step S2. On the other hand, when the current operation mode is an operation mode other than the cooling mode (for example, the heating mode or the dehumidifying heating mode), the control process is terminated as it is.

  In step S2, it is determined whether or not the air conditioner blowing temperature Tain is equal to or lower than the reference blowing temperature KTain. Here, the air conditioner blowing temperature Tain is an example of an index for determining whether the air conditioner heat load is high and the heat radiation of the outdoor heat exchanger 16 is large.

  The air conditioner blowing temperature Tain includes the inside air temperature Tr detected by the inside air temperature sensor 51, the outside air temperature Tam detected by the outside air temperature sensor 52, and the operating state of the inside / outside air switching device 33 (that is, the inside air volume and the outside air volume). Is calculated by the air conditioning control device 40 based on the air volume ratio).

  When the calculated air-conditioner blowing temperature Tain is equal to or lower than the reference blowing temperature KTain, it is determined that the air-conditioner heat load and the heat radiation in the outdoor heat exchanger 16 are not large, and the process proceeds to step S3. On the other hand, when the air conditioner blowing temperature Tain is not equal to or lower than the reference blowing temperature KTain, the air conditioner heat load and the heat radiation in the outdoor heat exchanger 16 are large, and the cooling of the engine radiator 71 and the inverter radiator 81 located downstream of the outdoor heat exchanger 16 It is determined that the performance is insufficient, and the process proceeds to step S4.

  In step S3, a target supercooling degree setting (A) process is performed. Specifically, the target supercooling degree TSC in this case is specified based on the lower limit line Ll in the control map shown in FIG. 5 and the outside air temperature Tam detected by the outside air temperature sensor 52. The lower limit line Ll is determined such that the cycle coefficient of performance COP is the highest. After specifying the target supercooling degree TSC in the target supercooling degree setting (A), this control process is terminated.

  In step S4, the target supercooling degree setting (B) is performed. Specifically, the target supercooling degree TSC in this case is specified based on the upper limit line Lh in the control map shown in FIG. 5 and the outside air temperature Tam detected by the outside air temperature sensor 52. After specifying the target supercooling degree TSC in the target supercooling degree setting (B), this control process is terminated.

  The upper limit line Lh in the control map is determined so that the cooling operation in the refrigeration cycle apparatus 10 can be continued and the degree of supercooling on the outlet side of the outdoor heat exchanger 16 is as large as possible. A value larger than the lower limit line Ll in the control map is shown. That is, the upper limit line Lh is determined with priority given to increasing the degree of supercooling SC rather than improving the coefficient of performance COP in the cooling mode.

  As described above, in the cooling mode, the target supercooling degree TSC corresponding to the air conditioner blowing temperature Tain is specified by the control process shown in FIG. Then, by adjusting the throttle opening degree of the second expansion valve 15b, the supercooling degree SC of the outdoor heat exchanger 16 is controlled so as to approach the target supercooling degree TSC specified by the control process of FIG.

  That is, when the heat load of the air conditioner is low and the heat radiation of the outdoor heat exchanger 16 is not so large, the target supercooling degree TSC is specified by the target supercooling degree setting (A) in step S3. When the supercooling degree SC on the outlet side of the outdoor heat exchanger 16 is controlled so as to approach the target supercooling degree TSC specified in step S3 during the cooling mode operation in this case, as shown in FIG. On the outlet 16b side of the outdoor heat exchanger 16, a supercooling region Rsca is formed.

  On the other hand, when the amount of heat released from the outdoor heat exchanger 16 is large and the cooling performance of the engine radiator 71 and the inverter radiator 81 is insufficient, the target supercooling degree TSC is specified by the target supercooling degree setting (B) in step S4. The

  Then, when the supercooling degree SC on the outlet side of the outdoor heat exchanger 16 is controlled so as to approach the target supercooling degree TSC specified in step S4, as shown in FIG. 2, the outlet of the outdoor heat exchanger 16 A supercooling region Rscb is formed on the 16b side.

  Under the condition of the same outside air temperature Tam, the target supercooling degree TSC specified in step S4 is larger than the target supercooling degree TSC specified in step S3. Therefore, as shown in FIG. 2, the supercooling region Rscb in this case is formed larger than the supercooling region Rsca based on the target supercooling degree TSC set in step S3.

  The cooling operation based on the target supercooling degree TSC in step S3 and the cooling operation based on the target supercooling degree TSC in step S4 will be compared.

  First, the coefficient of performance COP in the cooling operation in step S4 is lower than the coefficient of performance COP in the cooling operation in step S3 due to an increase in power of the compressor 11. For example, when the outside air temperature Tam is 40 ° C., the coefficient of performance COP decreases by about 8%.

  On the other hand, as shown in FIG. 2, the radiator front surface temperature Trf in the case of step S4 increases the supercooling region Rsca on the outlet side of the outdoor heat exchanger 16 to the supercooling region Rscb. Lower than the front surface temperature Trf. For example, when the outside air temperature Tam is 40 ° C., the radiator front surface temperature Trf decreases by about 3 ° C.

  The radiator front surface temperature Trf means the temperature of air in a space located downstream of the outdoor heat exchanger 16 and upstream of the engine radiator 71 and the inverter radiator 81 with respect to the flow of the outside air OA.

  Thus, in the vehicle air conditioner 1 according to the first embodiment, when the heat load of the air conditioner is low and the heat radiation of the outdoor heat exchanger 16 is not so large, the target supercooling degree setting (A) in step S3 sets the target. The degree of supercooling TSC is specified. In this case, since the target supercooling degree TSC is determined so that the coefficient of performance COP becomes a maximum value, the cooling operation can be continued in a state where the coefficient of performance COP is high.

  Further, since the heat radiation of the outdoor heat exchanger 16 does not increase so much, the engine ENG 71 can cool the engine ENG and the inverter radiator 81 can sufficiently cool the inverter INV.

  On the other hand, in a situation where the heat radiation amount in the outdoor heat exchanger 16 is large and the cooling performance of the engine radiator 71 and the inverter radiator 81 is insufficient, the target supercooling degree TSC is specified by the target supercooling degree setting (C) in step S4. . The target supercooling degree TSC in this case is determined so that the cooling operation in the refrigeration cycle apparatus 10 can be continued, and the supercooling degree on the outlet side of the outdoor heat exchanger 16 is as large as possible.

  Therefore, the vehicle air conditioner 1 can continue the cooling operation although the coefficient of performance COP is lower than in the case of the target supercooling degree setting (A). That is, the comfort in the passenger compartment can be maintained.

  Moreover, according to this vehicle air conditioner 1, the radiator front surface temperature Trf can be lowered on average by increasing the supercooling region in the outdoor heat exchanger 16. Thereby, since the fall of the heat exchange performance in the engine radiator 71 and the inverter radiator 81 can be suppressed, the vehicle air conditioner 1 can suppress the cooling performance shortage of the engine ENG and the inverter INV in this case.

  Next, the control process regarding the setting of the refrigerant discharge capacity of the compressor 11 in the vehicle air conditioner 1 will be described with reference to the drawings. As described above, in the vehicle air conditioner 1, the refrigerant discharge capacity of the compressor 11 is changed by controlling the number of revolutions of the electric motor constituting the compressor 11. In the cooling mode, the rotation speed of the compressor 11 is controlled so that the blown air blown from the indoor evaporator 18 becomes the target evaporator temperature TEO.

  In the control process shown in FIG. 6, the range of the number of rotations at which the compressor 11 operates is set by changing the upper limit value of the number of rotations that the electric motor of the compressor 11 can take. By appropriately setting the rotation speed range of the compressor 11, the air conditioning control device 40 is changed to the refrigerant discharge capacity of the compressor 11 according to the situation.

  First, in step S11, it is determined whether or not the operation mode is a cooling mode. If the current operation mode is the cooling mode, the process proceeds to step S12. On the other hand, if the current operation mode is other than the cooling mode, the control process is terminated as it is.

  In step S12, it is determined whether various sensors and various air conditioning control devices (hereinafter referred to as various sensors) connected to the air conditioning control device 40 are operating normally. This determination is made based on communication with control signals from various sensors and the like, and detection of operation errors and communication errors is detected.

  If it is determined that the various sensors are operating normally, the process proceeds to step S13. On the other hand, when it is determined that various sensors or the like are not operating normally, it is determined that an operation error or a communication error has occurred, and the process proceeds to step S14.

  In step S13, compressor speed setting (A) processing is executed. In this process, a range between the control maximum value Ncmax that is the maximum rotation speed of the compressor 11 determined by the performance of the compressor 11 and the control minimum value Ncmin that is the minimum rotation speed is set as the normal rotation speed range Rn. The Then, after setting the normal rotation speed range Rn, this control process is terminated.

  As shown in FIG. 7, in this normal rotation speed range Rn, the radiator front surface temperature Trf when the normal supercooling degree SCn is controlled is lower than the cooling upper limit temperature Tul. Here, the normal supercooling degree SCn means the supercooling degree SC when various sensors or the like are operating normally. The cooling upper limit temperature Tul means the upper limit value of the radiator front surface temperature Trf necessary for establishing cooling of the cooling target device.

  Therefore, in the cooling mode in this case, the rotation speed of the compressor 11 is determined so that the blown air blown out from the indoor evaporator 18 becomes the target evaporator temperature TEO within the normal rotation speed range Rn. . According to the cooling operation in this case, even if the rotation speed of any compressor 11 is determined, cooling of the cooling target device by the radiator can be established.

  In step S14, it is determined whether an error has occurred in a specific part. Here, the specific part is a part used when determining the magnitude of the air-conditioner thermal load among various sensors. If it is determined that an error has occurred in the specific part, the process proceeds to step S15. On the other hand, if it is determined that an error in a part different from the specific part has occurred, the process proceeds to step S16.

  Here, the specific part in the first embodiment means sensors for calculating the air conditioner blowing temperature Tain used for the determination of the air conditioner thermal load, and the inside air temperature sensor 51, the outside air temperature sensor 52, and the inside and outside air switching device. This corresponds to 33.

  In step S15, compressor speed setting (B) processing is executed. In this process, a range between the fail-safe rotation speed Ncf smaller than the maximum control value Ncmax and the minimum control value Ncmin is set as the rotation speed range Rf during failure. Thereafter, after setting the failure speed range Rf, this control process is terminated.

  Here, the fail-safe rotation speed Ncf in the first embodiment is determined based on the radiator front surface temperature Trf and the cooling upper limit temperature Tul in the case where the failure supercooling degree SCf is controlled. The supercooling degree SCf at the time of failure means the minimum supercooling degree SC for establishing the cooling mode.

  As shown in FIG. 7, the fail-safe rotation speed Ncf is the rotation speed of the compressor 11 at the time when the radiator front surface temperature Trf reaches the cooling upper limit temperature Tul in the case where the failure supercooling degree SCf is controlled.

  Therefore, in the cooling mode in this case, the rotational speed of the compressor 11 is determined so that the blown air blown out from the indoor evaporator 18 becomes the target evaporator temperature TEO within the range of the rotational speed range Rf during failure. The That is, in the cooling operation in this case, as long as the rotation speed of any compressor 11 is determined as long as it is within the range of the rotation speed range Rf at the time of failure, the cooling target device can be cooled by the radiator. .

  Further, the failure speed range Rf is narrower than the normal speed range Rn, but the operation of the compressor 11 is not stopped. That is, according to the vehicle air conditioner 1, the air conditioning operation in the cooling mode can be continued for at least a certain period even when an error occurs in the specific part.

  In step S16, the compressor rotation speed setting (C) process is executed with the occurrence of an error in a part different from the specific part. In this process, the rotation speed Nc of the compressor 11 is set to 0, and the operation of the compressor 11 is stopped. After the operation of the compressor 11 is stopped, this control process is terminated.

  Therefore, in the cooling operation in this case, since the operation of the compressor 11 is stopped, the cooling operation is not continued with serious errors in various sensors and the like. Thereby, the vehicle air conditioner 1 can prevent serious failure of various air conditioning control devices.

  In step S16, when an error in a part different from the specific part occurs, the operation of the compressor 11 is stopped. However, the present invention is not limited to this mode.

  For example, the operation of the compressor 11 may be stopped when there is an error in a part that is different from the specific part and satisfies a predetermined condition. As the predetermined condition in this case, for example, it may be a part that causes a serious failure of the vehicle air conditioner 1 or a part that is highly important for the air conditioning operation.

  As described above, according to the vehicle air conditioner 1 according to the first embodiment, the vehicle interior air conditioning by the refrigeration cycle apparatus 10, the cooling target device (for example, the engine) by the engine cooling water circuit 70 and the inverter cooling water circuit 80 ENG and inverter INV) can be cooled.

  As shown in FIG. 2, in the vehicle air conditioner 1, the engine radiator 71 and the inverter radiator 81 are downstream of the outdoor heat exchanger 16 with respect to the flow of the outside air OA introduced into the outdoor heat exchanger 16. Is arranged. Therefore, the heat radiation amount in the outdoor heat exchanger 16 (that is, the radiator front surface temperature Trf) affects the cooling performance of the cooling target equipment in the engine radiator 71 and the inverter radiator 81.

  Here, when an error occurs in a specific part (that is, the internal air temperature sensor 51 or the like) necessary for calculating the air conditioner blowing temperature Tain, the accuracy of the air conditioner blowing temperature Tain is lowered. Since this air conditioner blowing temperature Tain is used for specifying the target supercooling degree TSC in the cooling mode, the accuracy of the target supercooling degree TSC in the cooling mode is also reduced. May become a small value.

  On the other hand, in the vehicle air conditioner 1, in the cooling mode, the degree of supercooling SC on the outlet side of the outdoor heat exchanger 16 approaches the target degree of supercooling TSC by controlling the throttle opening of the second expansion valve 15b. To be adjusted.

  Therefore, an error in a specific part causes a decrease in the supercooling region Rsca formed on the outlet side of the outdoor heat exchanger 16 and increases the ambient temperature of the outdoor heat exchanger 16 (for example, the radiator front surface temperature Trf). . As a result, the cooling performance of the equipment to be cooled by the engine radiator 71 or the like is reduced.

  In this regard, in the vehicle air conditioner 1 according to the first embodiment, when an error occurs in the specific part, the rotation speed range of the compressor 11 is changed from the normal rotation speed range Rn to the failure rotation speed range in step S13. Change to Rf. As a result, as shown in FIG. 7, even when an error occurs in a specific part, the radiator front surface temperature Trf can be made equal to or lower than the cooling upper limit temperature Tul.

  That is, the vehicle air conditioner 1 does not stop the operation of the compressor 11 for a while even when the target supercooling degree TSC cannot be normally specified due to the occurrence of an error in a specific part. And the fall of the cooling performance by the engine radiator 71 grade | etc., Can be suppressed. In other words, the vehicle air conditioner 1 can continue air conditioning in the passenger compartment while maintaining the cooling performance of the cooling target device by the engine radiator 71 and the like for a certain degree.

  Further, as shown in FIG. 2, the inverter radiator 81 is disposed downstream of the outside air OA with respect to the outlet 16b of the outdoor heat exchanger 16 in which the supercooling region is formed. The engine radiator 71 is an inverter Arranged above the radiator 81. Therefore, the vehicle air conditioner 1 can ensure the cooling performance in a mode suitable for each of the engine ENG and the inverter INV.

(Second Embodiment)
Next, a second embodiment different from the first embodiment described above will be described with reference to the drawings. The vehicle air conditioner 1 according to the second embodiment has basically the same configuration as that of the first embodiment, except for the setting mode of the rotation speed range Rf during failure when an error of a specific part has occurred. . Accordingly, in the following description, the same reference numerals as those in the first embodiment indicate the same configuration, and the preceding description is referred to.

  Hereinafter, the point in which the vehicle air conditioner 1 which concerns on 2nd Embodiment is different from 1st Embodiment is demonstrated, referring FIG.

  Even in the cooling mode according to the second embodiment, the air conditioning control device 40 controls the second expansion valve 15b so that the degree of supercooling SC on the outlet side of the outdoor heat exchanger 16 approaches the target degree of supercooling TSC. Control the throttle opening. Further, with respect to the control process related to the setting of the refrigerant discharge capacity of the compressor 11, the same process as in the first embodiment is performed except for the processing content of the compressor rotation speed setting (B) in step S15.

  In the first embodiment described above, in step S15, the fail-time rotation speed range Rf is specified using the predetermined fail-safe rotation speed Ncf. In this regard, in the second embodiment, the fail-safe rotation speed Ncf is specified according to the inverter cooling water temperature TWhv, which is an index indicating the cooling load of the cooling target device (that is, the inverter INV), and the failure rotation speed range is determined. Rf is determined.

  Specifically, when the process proceeds to step S15, the inverter cooling water temperature TWhv is specified based on the detection signal from the inverter cooling water temperature sensor 82. Then, by referring to the inverter cooling water temperature TWhv and the control map shown in FIG. 8, the fail-safe rotation speed Ncf corresponding to the cooling load of the cooling target device is specified.

  As shown in FIG. 8, when inverter cooling water temperature TWhv is lower than a predetermined reference cooling water temperature KTa, fail-safe rotation speed Ncf is specified as a fail-safe rotation speed Ncfa having a predetermined rotation speed. . Further, when the inverter cooling water temperature TWhv is higher than the reference cooling water temperature KTb, the fail-safe rotation speed Ncf is specified as a fail-safe rotation speed Ncfb having a rotation speed smaller than the fail-safe rotation speed Ncfa.

  When the inverter cooling water temperature TWhv is within the range from the reference cooling water temperature KTa to the reference cooling water temperature KTb, the fail-safe rotation speed Ncf decreases as the inverter cooling water temperature TWhv increases. The rotation speed is specified as Ncf.

  Thus, in the vehicle air conditioner 1 according to the second embodiment, in step S15, the fail-safe rotation speed Ncf is specified according to the cooling load of the cooling target device indicated by the inverter cooling water temperature TWhv. Then, based on the fail-safe rotation speed Ncf and the minimum control value Ncmin, a fail-time rotation speed range Rf is specified.

  Therefore, the failure speed range Rf in the second embodiment is set to a range corresponding to the cooling load of the cooling target device. Thus, the vehicle air conditioner 1 maintains the cooling performance of the cooling target device and operates the vehicle interior air conditioner even when the target supercooling degree TSC cannot be normally specified due to the occurrence of an error in the specific part. Continuation can be achieved with an appropriate balance in consideration of the cooling load of the equipment to be cooled.

  As described above, the vehicle air conditioner 1 according to the second embodiment has a certain degree of time even when the target supercooling degree TSC cannot be normally specified due to the occurrence of an error in a specific part. Without stopping the operation of the compressor 11, it is possible to suppress a decrease in cooling performance due to the engine radiator 71 and the like. In other words, the vehicle air conditioner 1 can continue air conditioning in the passenger compartment while maintaining the cooling performance of the cooling target device by the engine radiator 71 and the like for a certain degree.

  At this time, since the fail speed range Rf corresponding to the cooling load of the cooling target device can be set, the cooling performance of the cooling target device is maintained and the operation of the vehicle interior air conditioning is continued. Both can be achieved with an appropriate balance considering the load.

(Third embodiment)
Next, a third embodiment different from the above-described embodiments will be described with reference to the drawings. The vehicle air conditioner 1 according to the third embodiment has basically the same configuration as that of the above-described embodiment except for the setting mode of the rotation speed range Rf during failure when an error of a specific part has occurred. . Accordingly, in the following description, the same reference numerals as those in the above-described embodiment indicate the same configuration, and the preceding description is referred to.

  Hereinafter, the point in which the vehicle air conditioner 1 which concerns on 3rd Embodiment differs from 1st Embodiment is demonstrated, referring FIG.

  Even in the cooling mode according to the third embodiment, the air conditioning control device 40 controls the second expansion valve 15b so that the degree of supercooling SC on the outlet side of the outdoor heat exchanger 16 approaches the target degree of supercooling TSC. Control the throttle opening. Further, with respect to the control process relating to the setting of the refrigerant discharge capacity of the compressor 11, the same process as that of each of the above-described embodiments is performed except for the processing content of the compressor speed setting (B) in step S15.

  In the first embodiment described above, in step S15, the fail-speed rotation speed range Rf is specified using the predetermined fail-safe rotation speed Ncf, and the fail-safe rotation is determined according to the inverter cooling water temperature TWhv. The number Ncf was specified, and the failure speed range Rf was determined.

  In this regard, in the third embodiment, the fail-safe rotation speed Ncf is specified according to the outside air temperature Tam which is one of the indices indicating the air conditioner heat load, and the failure rotation speed range Rf is specified. Specifically, when the process proceeds to step S15, the outside air temperature Tam is specified based on the detection signal from the outside air temperature sensor 52. Then, by referring to the outside air temperature Tam and the control map shown in FIG. 9, the fail-safe rotation speed Ncf corresponding to the air conditioner heat load is specified.

  As shown in FIG. 9, when the outside air temperature Tam is lower than a predetermined reference outside air temperature KTc, the fail-safe rotation speed Ncf is specified as a fail-safe rotation speed Ncfc having a predetermined rotation speed. Further, when the outside air temperature Tam is higher than the reference outside air temperature KTd, the fail-safe rotation speed Ncf is specified as a fail-safe rotation speed Ncfd having a higher rotation speed than the fail-safe rotation speed Ncfc.

  When the outside air temperature Tam is within the range from the reference outside air temperature KTc to the reference outside air temperature KTd, the fail-safe rotation speed Ncf is specified such that the rotation speed increases as the outside air temperature Tam increases.

  Thus, in the vehicle air conditioner 1 according to the third embodiment, the fail-safe rotation speed Ncf is specified in step S15 according to the air conditioner heat load indicated by the outside air temperature Tam. Then, based on the fail-safe rotation speed Ncf and the minimum control value Ncmin, a fail-time rotation speed range Rf is specified.

  Therefore, the failure speed range Rf in the third embodiment is set to a range corresponding to the air conditioner heat load. Thus, the vehicle air conditioner 1 maintains the cooling performance of the cooling target device and operates the vehicle interior air conditioner even when the target supercooling degree TSC cannot be normally specified due to the occurrence of an error in the specific part. Continuation can be achieved with an appropriate balance considering the heat load of the air conditioner.

  As described above, the vehicle air conditioner 1 according to the third embodiment has a certain amount of time even if the target supercooling degree TSC cannot be normally specified due to the occurrence of an error in a specific part. Without stopping the operation of the compressor 11, it is possible to suppress a decrease in cooling performance due to the engine radiator 71 and the like. In other words, the vehicle air conditioner 1 can continue air conditioning in the passenger compartment while maintaining the cooling performance of the cooling target device by the engine radiator 71 and the like for a certain degree.

  At this time, since the rotation speed range Rf at the time of failure corresponding to the air conditioner heat load can be set, the air conditioner heat load in the refrigeration cycle apparatus 10 can be maintained by maintaining the cooling performance of the cooling target device and continuing the operation of the vehicle interior air conditioner Can be achieved with an appropriate balance in consideration of

(Fourth embodiment)
Subsequently, a fourth embodiment different from the above-described embodiments will be described with reference to the drawings. The vehicle air conditioner 1 according to the fourth embodiment has basically the same configuration as that of the above-described embodiment except for the content of the control process related to the setting of the refrigerant discharge capacity of the compressor 11. Accordingly, in the following description, the same reference numerals as those in the above-described embodiment indicate the same configuration, and the preceding description is referred to.

  Hereinafter, the point in which the vehicle air conditioner 1 which concerns on 4th Embodiment differs from 1st Embodiment is demonstrated, referring FIG. Even in the cooling mode according to the fourth embodiment, the air conditioning control device 40 opens the second expansion valve 15b so that the degree of supercooling SC on the outlet side of the outdoor heat exchanger 16 approaches the target degree of supercooling TSC. Control the degree.

  Even in the cooling mode according to the fourth embodiment, the air conditioning control device 40 controls the second expansion valve 15b so that the degree of supercooling SC on the outlet side of the outdoor heat exchanger 16 approaches the target degree of supercooling TSC. Control the throttle opening. Also, the control process related to the setting of the refrigerant discharge capacity of the compressor 11 is different from the above-described embodiments, and the process shown in the flowchart of FIG. 10 is executed.

  As shown in FIG. 10, in step S21, it is first determined whether or not the operation mode is a cooling mode. If the current operation mode is the cooling mode, the process proceeds to step S22. On the other hand, if the current operation mode is other than the cooling mode, the control process is terminated as it is.

  In step S22, it is determined whether or not various sensors are operating normally. The determination in step S22 is executed in the same manner as in step S12 in the first embodiment. If it is determined that the various sensors are operating normally, the process proceeds to step S23. On the other hand, if it is determined that various sensors or the like are not operating normally, it is determined that an operation error or a communication error has occurred, and the process proceeds to step S24.

  In step S23, compressor speed setting (A) processing is executed. In the process of step S23, the same process as S13 in the first embodiment is performed. Therefore, as shown in FIG. 7, the normal rotational speed range Rn defined by the maximum control value Ncmax and the minimum control value Ncmin is set as the rotational speed control range of the compressor 11. Thereafter, this control process is terminated.

  In step S24, it is determined whether an error has occurred in a specific part. This determination process is executed in the same manner as step S14 in the first embodiment. If it is determined that an error has occurred in the specific part, the process proceeds to step S25. On the other hand, if it is determined that an error has occurred in a part different from the specific part, the process proceeds to step S26.

  In step S25, it is determined whether or not an air conditioning control change signal output from the vehicle control device 90 has been detected. As described above, the air conditioning control change signal is output from the vehicle control device 90 when the cooling load of the engine ENG by the engine coolant circuit 70 or the cooling load of the inverter INV by the inverter coolant circuit 80 is excessive. The air conditioning control change signal is required to change the control content of the air conditioning operation in order to protect the vehicle traveling system.

  When the air conditioning control change signal is detected, it is determined that the cooling load of the cooling target device by the engine radiator 71 or the like is excessive, and the process proceeds to step S26. On the other hand, when the air conditioning control change signal is not detected, it is determined that the cooling load of the cooling target device is not excessive, and the process proceeds to step S23.

  In step S26, compressor speed setting (B) processing is executed. In this process, the same process as step S15 in the first embodiment is executed. Therefore, as shown in FIG. 7, a fail-time rotation speed range Rf defined by the fail-safe rotation speed Ncf and the minimum control value Ncmin is set as the control range of the rotation speed of the compressor 11.

  In this case, the fail-safe rotation speed Ncf is, as shown in FIG. 7, the value of the compressor 11 at the time when the radiator front surface temperature Trf is controlled to the supercooling degree SCf at the time of failure and the cooling upper limit temperature Tul. The number of revolutions. That is, the fail-safe rotation speed Ncf in the fourth embodiment is a predetermined specified value. After setting the failure speed range Rf, this control process is terminated.

  In step S27, a compressor rotation speed setting (C) process is executed with the occurrence of an error in a part different from the specific part. In this process, similarly to the first embodiment, the rotation speed Nc of the compressor 11 is set to 0, and the operation of the compressor 11 is stopped. After the operation of the compressor 11 is stopped, this control process is terminated.

  As described above, the vehicle air conditioner 1 according to the fourth embodiment has a certain degree of time even when the target supercooling degree TSC cannot be normally specified due to the occurrence of an error in a specific part. Without stopping the operation of the compressor 11, it is possible to suppress a decrease in cooling performance due to the engine radiator 71 and the like. In other words, the vehicle air conditioner 1 can continue air conditioning in the passenger compartment while maintaining the cooling performance of the cooling target device by the engine radiator 71 and the like for a certain degree.

  At this time, in accordance with the detection of the air conditioning control change signal, the failure rotation speed range Rf corresponding to the cooling load of the equipment to be cooled can be set, so that the cooling performance of the equipment to be cooled can be maintained and the air conditioning in the passenger compartment can be operated. Continuation can be achieved with an appropriate balance in consideration of the cooling load of the equipment to be cooled.

(Other embodiments)
As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to embodiment mentioned above at all. That is, various improvements and modifications can be made without departing from the spirit of the present invention. For example, the above-described embodiments may be combined as appropriate, and the above-described embodiments may be variously modified.

  (1) In the above-described embodiment, the refrigerant discharge capacity in the compressor 11 is controlled by the number of rotations of the electric motor that constitutes the compressor 11, but is not limited to this aspect. For example, if the compressor 11 is a variable capacity compressor, the refrigerant discharge capacity of the compressor 11 may be controlled using a control current, a control voltage, a duty signal, or the like.

  (2) In the second embodiment described above, the cooling load of the inverter cooling water circuit 80 is determined using the inverter cooling water temperature TWhv, and the fail-safe rotation speed Ncf and the failure rotation speed range Rf are specified. However, it is not limited to this aspect. Various modifications are possible as long as the cooling load of the device to be cooled is determined based on the temperature of the heat medium in the radiator and the refrigerant discharge capacity of the compressor 11 is controlled.

  For example, the cooling load of the engine coolant circuit 70 is determined based on the engine coolant temperature detected by the engine coolant temperature sensor 72, and the fail-safe rotation speed Ncf corresponding to this is specified. And it is also possible to configure so that the fail-time rotation speed range Rf is set using the specified fail-safe rotation speed Ncf.

  (3) In the above-described third embodiment, the air-conditioner heat load is determined using the outside air temperature Tam, and the fail-safe rotation speed Ncf and the fail-time rotation speed range Rf are specified. Is not to be done. For example, the intake air temperature in the engine ENG may be used as a substitute for the outside air temperature Tam.

  Moreover, it is sufficient if the magnitude of the air-conditioner heat load can be determined, and a plurality of types of sensors may be used. For example, an air conditioner thermal load is identified using the solar radiation amount As detected by the solar radiation sensor 53 and the outside air temperature Tam of the outside air temperature sensor 52, and the fail-safe rotation speed Ncf and the fail time corresponding to the identified air conditioner heat load are determined. It is also possible to set the rotation speed range Rf.

  (4) In the fourth embodiment described above, the fail-time rotation speed range Rf is set using the fail-safe rotation speed Ncf that is predetermined in the compressor rotation speed setting (B). However, the present invention is limited to this mode. Is not to be done. For example, if the air conditioning control change signal includes information indicating the size of the cooling load of the cooling target device, the fail-safe rotation speed Ncf is set according to the size of the cooling load based on this signal. Specifically, a fail speed range Rf may be set. Also in this case, the fail-safe rotation speed Ncf may be specified using detection values of various sensors or the like.

  (5) Moreover, although the refrigerating-cycle apparatus 10 which concerns on each above-mentioned embodiment was comprised so that a cooling operation, heating operation, and dehumidification heating operation could be switched, it is not limited to this aspect. For example, in addition to each operation mode in the above-described embodiment, it is possible to be configured to be switchable to the defrosting operation mode.

  (6) The dehumidifying and heating mode in each of the above-described embodiments is configured by a refrigeration cycle in which the outdoor heat exchanger 16 and the indoor evaporator 18 are connected in parallel to the refrigerant flow. It is not limited. For example, the refrigerant flows in the order of the compressor 11 → the indoor condenser 12 → the first expansion valve 15 a → the outdoor heat exchanger 16 → the second expansion valve 15 b → the indoor evaporator 18 → the evaporation pressure adjusting valve 19 → the accumulator 20 → the compressor 11. It is also possible to perform a dehumidifying and heating operation by a circulating vapor compression refrigeration cycle. In this case, a refrigeration cycle is configured in which the outdoor heat exchanger 16 and the indoor evaporator 18 are connected in series to the refrigerant flow.

  Further, in the dehumidifying and heating mode, a refrigeration cycle in which the outdoor heat exchanger 16 and the indoor evaporator 18 are connected in parallel with the refrigerant flow, and the outdoor heat exchanger 16 and the indoor evaporator 18 are in series with the refrigerant flow. It is also possible to switch between the refrigeration cycles connected to each other as appropriate.

  (7) In each of the above-described embodiments, the example in which each operation mode is switched by executing the air conditioning control program has been described. However, the switching of each operation mode is not limited to this. For example, each operation mode may be switched with reference to a control map stored in advance in the air conditioning control device 40 based on the target blowing temperature TAO and the outside air temperature Tam.

  Further, an operation mode setting switch for setting each operation mode may be provided on the operation panel 60, and the cooling mode, the dehumidifying heating mode, and the heating mode may be switched according to an operation signal of the operation mode setting switch.

DESCRIPTION OF SYMBOLS 1 Vehicle air conditioner 11 Compressor 16 Outdoor heat exchanger 15b 2nd expansion valve 18 Indoor evaporator 40 Air-conditioning control device 51 Internal air temperature sensor 52 External air temperature sensor 33 Internal / external air switching device 81 Inverter radiator

Claims (6)

A compressor (11) for compressing and discharging the refrigerant;
A radiator (16) for radiating heat from the refrigerant discharged from the compressor;
A pressure reducing device (15b) capable of adjusting the degree of supercooling of the refrigerant on the outlet side of the radiator, while depressurizing the refrigerant radiated by the radiator.
A refrigeration cycle comprising: an evaporator (18) for exchanging heat between the refrigerant decompressed by the decompression device and air to evaporate the refrigerant;
With respect to the flow of air introduced into the radiator (16), a heat medium that is disposed downstream of the radiator and absorbs heat from a cooling target device (ENG, INV) mounted on a vehicle, and the air Radiators (71, 81) for exchanging heat;
An internal air temperature detecting unit (51) for detecting an internal air temperature that is the temperature in the vehicle interior;
An outside air temperature detecting unit (52) for detecting an outside air temperature which is a temperature outside the vehicle compartment;
An introduction air adjusting section (33) for adjusting the air introduced as a heat exchange target in the evaporator using the inside air that is the air inside the vehicle interior and the outside air that is the air outside the vehicle compartment;
A detection result of the internal air temperature detection unit, a detection result of the external air temperature detection unit, and a target supercooling degree specifying unit (40) for specifying a target supercooling degree using an operation mode of the introduction air adjusting unit;
A decompression control section (40c) for controlling the operation of the decompression device (15b);
A discharge capacity control section (40a) for controlling the discharge capacity of the refrigerant in the compressor (11),
The decompression control unit (40c) controls the decompression device (15b) so that the degree of supercooling approaches the target degree of supercooling specified by the target degree of supercooling specifying unit,
The discharge capacity control unit (40a) determines the discharge capacity of the compressor (11) and the target supercooling degree when the target supercooling degree specifying unit cannot normally specify the target supercooling degree. A vehicle air conditioner that reduces the amount compared to when it can be identified normally. A cooling load detector (40) for detecting a cooling load of the device to be cooled by the radiator (71, 81),
The discharge capacity adjusting unit (40a) increases the cooling load detected by the cooling load detection unit when the target supercooling degree cannot be normally specified by the target supercooling degree specifying unit. The vehicle air conditioner according to claim 1, wherein the reduction amount of the discharge capacity in the compressor (11) is increased. The radiator (71, 81) has a heat medium temperature detection unit (72, 82) that detects the temperature of the heat medium that exchanges heat with the air,
The radiator (71, 81)
With respect to the flow of air introduced into the radiator (16), heat exchange is performed between the air and the heat medium that is disposed downstream of the radiator and absorbs heat from an engine (ENG) mounted on a vehicle. An engine radiator (71);
With respect to the flow of air introduced into the radiator (16), heat is exchanged between the heat medium that is disposed downstream of the radiator and has absorbed heat from an inverter (INV) mounted on a vehicle. An inverter radiator (81),
The cooling load detector (40) uses the temperature of the heat medium in the engine radiator detected by the heat medium temperature detector (72, 82) or the temperature of the heat medium in the inverter radiator, The vehicle air conditioner according to claim 2, wherein a cooling load of the device to be cooled by the radiator (71, 81) is detected. A control change signal detection unit (S25) for detecting an air conditioning control change signal for requesting a change in the air conditioning control content by a cooling load of the cooling target device by the radiator (71, 81);
The said cooling load detection part (40) detects the cooling load of the said cooling object apparatus by the said radiator (71, 81) using the said air-conditioning control change signal detected by the said control change signal detection part. Or the vehicle air conditioner of 3. An air conditioning thermal load detector (40) for detecting an air conditioning thermal load in the vehicle air conditioner,
The discharge capacity adjustment unit (40a) increases the air conditioning thermal load detected by the air conditioning thermal load detection unit when the target supercooling degree cannot be normally specified by the target supercooling degree specifying unit. The air conditioner for vehicles according to claim 1 which increases the amount of decrease of discharge capacity in said compressor (11) with it. The radiator (71, 81)
With respect to the flow of air introduced into the radiator (16), heat exchange is performed between the air and the heat medium that is disposed downstream of the radiator and absorbs heat from an engine (ENG) mounted on a vehicle. An engine radiator (71);
With respect to the flow of air introduced into the radiator (16), heat is exchanged between the heat medium that is disposed downstream of the radiator and has absorbed heat from an inverter (INV) mounted on a vehicle. An inverter radiator (81),
The said inverter radiator (81) is arrange | positioned so that it may become a downstream with respect to the supercooling area (Rsca, Rscb) which arises in the said heat radiator (16) regarding the said air flow. The vehicle air conditioner according to claim 1.

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