JP2012162149A - Heat pump type vehicular air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat pump type vehicular air conditioner, excellent in mountability at low cost, capable of solving problems in frosting, and suitable for EV and HEV vehicles only by sharing a cooling cycle and HVAC of an air conditioner for a gasoline fueled vehicle and adding a minimum heating circuit and equipment.SOLUTION: The heat pump type air conditioner 1 for a vehicle includes: an HVAC unit 2 provided with an indoor evaporator 9 and a heater core 10; a coolant circulation circuit 5 including the heater core 10; a refrigeration cycle 27 for cooling including the indoor evaporator 9 with a second heating circuit 35 having a refrigerant/coolant heat exchanger 28, a first heating circuit 30, a second expansion valve 32 and an outdoor evaporator 33 added to the refrigeration cycle 27; and a heat pump cycle 36 for heating for sharing a circuit, equipment, and the like having a pressure condition same as the refrigeration cycle 27 for cooling, and, in heating, can switch to dehumidifying heating in which the refrigerant is flown to the indoor evaporator 9 side when frost is attached to the outdoor evaporator 33.

Description

  The present invention relates to a heat pump vehicle air conditioner suitable for an air conditioner for a next-generation vehicle such as an electric vehicle or a hybrid vehicle.

  In an electric vehicle (EV), engine exhaust heat cannot be used for heating. In hybrid vehicles (HEV, PHEV, etc.), in order to save fuel, the engine is controlled to be stopped as much as possible. Therefore, heating by a heat pump or heating by an electric heater has been studied. However, the electric power consumed by these heating systems is very large. Therefore, the heat pump system capable of high COP (coefficient of performance) heating is preferable to the electric heater system (COP ≦ 1), but various types of exhaust are required. When trying to construct a high COP heat pump heating system that can use heat, there are problems such as an increase in the number of parts and an increase in cost.

  On the other hand, the current situation is in a transitional period from the transition from gasoline cars to next-generation cars such as EV cars, HEVs, PHEV cars, etc., so in order to suppress enormous development costs, improve and apply air conditioners for gasoline cars Attempts have been made. Usually, in the case of a gasoline vehicle, a system is used in which a heater core is provided in an HVAC unit, coolant for cooling the engine is circulated, and the engine is heated by exhaust heat of the engine. However, in the heat pump system, the HVAC unit (Heating Ventilation and Air) A system in which an in-vehicle condenser (sub-capacitor) is provided in the Conditioning Unit is common, and there is a great difference in configuration.

  In particular, in the case of a general heat pump system, during heating, the refrigerant circuit is switched so that the condenser functions as an evaporator and the evaporator functions as a condenser. Therefore, the piping, evaporator, and condenser that constitute the refrigerant circuit The heat exchanger such as the above must be configured to be shared under different pressure conditions of the cooling operation and the heating operation, and it is necessary to significantly change the vehicle air conditioner applied to the current gasoline vehicle. In addition, when the evaporator on the outside of the vehicle is frosted at a low outside air temperature, how to defrost it becomes a big problem. Furthermore, although diversion of the existing HVAC unit is also being studied, it is difficult to provide an in-vehicle condenser (sub-condenser) in the HVAC unit having a heater core from the viewpoint of packaging and temperature control.

  Under such circumstances, as an example of a vehicle air conditioner that enables heat pump heating while using the evaporator of the current system as an in-vehicle evaporator provided in the HVAC unit, the one shown in Patent Document 1 has been proposed. . In this system, an in-vehicle condenser is installed on the downstream side of the in-vehicle evaporator of the HVAC unit of the vehicle air conditioner equipped with the current cooling refrigeration cycle, and the in-vehicle condenser is connected to the discharge circuit of the compressor. A bypass circuit having a second electromagnetic valve connected to the second electronic expansion valve and the in-vehicle evaporator is connected to a parallel circuit of the first electronic expansion valve and a bypass circuit including the first electromagnetic valve on the outlet side thereof. It is configured to connect.

  Patent Document 2 discloses a bypass circuit in which an HVAC unit provided with an in-vehicle evaporator and a heater core is left as it is, and a water / refrigerant heat exchanger, an expansion valve, and an open / close valve are provided in a compressor discharge pipe of a cooling cycle. And provided with a parallel circuit. This makes it possible to heat engine cooling water with a water / refrigerant heat exchanger, and at the time of heating or dehumidifying heating, the refrigerant is circulated to the water / refrigerant heat exchanger side, where the cooling water is heated and the condenser outside the vehicle. Is made to function as an evaporator and absorbs heat, thereby improving the heating performance.

JP 2010-111222 A JP 2010-42698 A

  Patent Document 1 shows that even when the evaporator on the outside of the vehicle is frosted during heating, the air conditioner is operated with the outside fan stopped, and the amount of heat corresponding to the work of the compressor is condensed inside the vehicle. The outside evaporator can be defrosted while obtaining a feeling of heating by dissipating heat from the evaporator and the outside evaporator. However, in the above configuration, the external condenser and the refrigerant piping system connected to the external condenser need to be a heat exchanger having both a condensing function and an evaporation function, and a piping system for both high and low pressures. The refrigerant circuit and the HVAC unit of the system had to be significantly changed, and it was difficult to manufacture a heat pump type vehicle air conditioner with a low cost and simple configuration by sharing the external condenser and refrigerant piping system. .

  Moreover, in what is shown by patent document 2, at the time of heating mode, a cooling water can be heated with a water / refrigerant heat exchanger, and heating performance can be improved. However, when frost forms on the outside evaporator during the heat pump heating operation, there is a problem that the function is interrupted, and no solution is presented for a method of defrosting the outside evaporator frost. Further, in such a configuration, when a command to change the blowing temperature is issued during the maximum cooling operation, the hot gas from the compressor is switched to the water / refrigerant heat exchanger side, and the heated water is circulated to the heater core. There is a problem that it is necessary to control the temperature and there is a concern that the temperature control performance may be deteriorated due to a response delay.

  The present invention has been made in view of such circumstances, and the cooling cycle and the HVAC unit of the current gasoline vehicle air conditioner are shared, and a minimum heating circuit and equipment having different pressure conditions are added. The purpose of the present invention is to provide a heat pump type vehicle air conditioner suitable for electric vehicles, hybrid vehicles, etc., which is low in cost and excellent in mountability and can also solve the problem of frost formation on the outside evaporator. To do.

In order to solve the above-described problems, the heat pump type vehicle air conditioner of the present invention employs the following means.
That is, the heat pump type vehicle air conditioner according to the present invention includes an in-vehicle evaporator and a heater core, and any one of a plurality of outlets provided on the downstream side of the temperature-controlled air by the in-vehicle evaporator and the heater core. An HVAC unit that blows air out of the vehicle to air-condition the interior of the vehicle, a coolant circulation circuit that can circulate coolant that cools vehicle drive devices such as the engine, motor, and inverter to the heater core, an electric compressor, Refrigeration cycle for cooling in which a condenser, a receiver, a first expansion valve, and the in-vehicle evaporator are connected in this order, and provided in a discharge pipe of the electric compressor, circulate in the hot gas refrigerant and the coolant circulation circuit A refrigerant / coolant heat exchanger for exchanging heat with the coolant, and an inlet side of the external condenser A first heating circuit connected to the receiver via a switching means, and connected between the outlet side of the receiver and the suction side of the electric compressor, and a second expansion valve and an outside evaporator are provided. A second heating circuit, and the electric compressor, the refrigerant / coolant heat exchanger, the switching means, the first heating circuit, the receiver, the second expansion valve, and the outside evaporator. Further, the second heating circuit constitutes a heat pump cycle for heating, the coolant heated by the refrigerant / coolant heat exchanger can be circulated to the heater core, and the outside evaporation is performed during heating by the heating heat pump cycle. When frost formation is detected with respect to the heater, the refrigerant flow to the second heating circuit side is interrupted and the refrigerant is circulated to the in-vehicle evaporator side. Characterized in that it is capable switched to heating.

  According to the present invention, a coolant circulation circuit capable of circulating coolant for cooling vehicle driving equipment such as an engine, a motor and an inverter is connected to the heater core of the HVAC unit, and electric compression is applied to the in-vehicle evaporator. The HVAC unit is applied to a gasoline vehicle and the HVAC unit of the current vehicle air conditioner applied to the gasoline vehicle is connected to a cooling refrigeration cycle composed of a compressor, an external condenser, a receiver, a first expansion valve, etc. It can be set as a substantially identical structure. Further, a second heating circuit including a refrigerant / coolant heat exchanger, a first heating circuit, a second expansion valve and an outside-vehicle evaporator is additionally provided for the cooling refrigeration cycle, and the electric compressor, the refrigerant / Coolant heat exchanger, switching means, first heating circuit, receiver, second expansion valve, and second heating circuit including an outside evaporator constitute a heat pump cycle for heating, so cooling that is the original form By connecting a minimum heating circuit and equipment such as a second heating circuit with a refrigerant / coolant heat exchanger, a first heating circuit, a second expansion valve and an outside-vehicle evaporator to the refrigeration cycle for It is possible to configure a heat pump cycle for heating by sharing refrigerant circuits and devices having the same pressure condition. Accordingly, a refrigerant circuit having the same pressure condition as the cooling cycle of a vehicle air conditioner applied to an existing gasoline vehicle without newly developing a refrigerant circuit and an HVAC unit that can withstand both cooling and heating operations. By simply adding a minimum number of heating circuits and equipment that share different pressure conditions, the configuration is relatively simple, low cost, and easy to mount, making it suitable for electric and hybrid vehicles. It is possible to provide a highly reliable heat pump type vehicle air conditioner that can be applied. In addition, even when the outside evaporator is frosted at low outside air temperature, the refrigerant flow to the second heating circuit is cut off and the refrigerant flows to the inside evaporator side, and switching to dehumidifying heating using the inside evaporator is performed. Since the configuration is possible, even if the outside evaporator is frosted, the efficient heat pump heating operation can be continued as it is. Therefore, the interruption of the heating operation and the loss of power consumption due to switching to the defrosting operation during the heating operation can be eliminated.

  Furthermore, the heat pump vehicle air conditioner of the present invention is the above heat pump vehicle air conditioner, wherein the refrigerant / coolant heat exchanger includes the hot gas refrigerant discharged from the electric compressor and the coolant circulation circuit. The circulating coolant is configured to be able to exchange heat at all times.

  According to the present invention, the refrigerant / coolant heat exchanger is configured such that the hot gas refrigerant discharged from the electric compressor and the coolant circulating in the coolant circulation circuit can always exchange heat, so that only during heating operation. In addition, it is possible to operate while always circulating a high-temperature coolant through the heater core even during the cooling operation and the dehumidifying operation. Therefore, even when a blowout temperature change command is suddenly issued from the controller during the maximum cooling operation, it is possible to instantaneously control the target blowout temperature by controlling the temperature with the temperature control damper. Control responsiveness can be ensured.

  Furthermore, the heat pump type vehicle air conditioner according to the present invention is the above heat pump type vehicle air conditioner, wherein the outside evaporator includes the outside condenser in the ventilation path of the outside fan for the outside condenser and / or It is arranged on the downstream side of the radiator for heat dissipation connected to the coolant circulation circuit.

  According to the present invention, the outside evaporator is disposed downstream of the radiator for heat dissipation connected to the outside condenser and / or the coolant circulation circuit in the ventilation path of the outside fan for the outside condenser, Even during snowfall or snow accumulation in winter, the adhesion and accumulation of snow on the outside evaporator can be blocked and reduced by the outside condenser and / or the radiator for heat dissipation. Therefore, it is possible to prevent the outside evaporator from freezing due to snow adhesion and accumulation, and to ensure the heat exchange performance by the outside evaporator and improve the heating performance. Further, when heat is radiated from the radiator, the heating capacity can be further improved by absorbing the heat with an evaporator outside the vehicle.

  Furthermore, the heat pump type vehicle air conditioner according to the present invention is the above heat pump type vehicle air conditioner, wherein when the frost formation is detected on the outside evaporator during the heating by the heating heat pump cycle, the second Blocking the refrigerant flow to the heating circuit side and circulating the refrigerant to the in-vehicle evaporator side, continuing heating, and when the outside air temperature is equal to or higher than a predetermined value, the outside evaporator is naturally defrosted by outside air, When the outside air temperature is a predetermined value or less, the coolant heated through the coolant circulation circuit is circulated through the radiator to dissipate heat to the outside air, and the outside evaporator is defrosted by the heat. Features.

  According to the present invention, during heating by the heating heat pump cycle, when frost formation is detected on the outside evaporator, the refrigerant flow to the second heating circuit side is interrupted and the refrigerant flows to the inside evaporator side. When the outside air temperature is above a predetermined value, the outside evaporator is naturally defrosted with outside air, and when the outside air temperature is below the predetermined value, the coolant is heated to the radiator via the coolant circulation circuit. Is circulated to dissipate heat to the outside air, and the outside evaporator is defrosted by the heat, so if frost formation is detected on the outside evaporator during heating operation at low outside air temperature, the engine The exhaust heat of vehicle drive equipment such as motors and inverters can be used to raise the temperature of the coolant and to improve the heating performance, and part of the heat is dissipated from the radiator and heated. Utilizing the wind may be defrosting efficient and effective the outside evaporator. Therefore, heating and defrosting can be performed by effectively using the exhaust heat of the vehicle drive device, and power saving can be achieved.

  According to the present invention, the HVAC unit can have substantially the same configuration as the HVAC unit of the current vehicle air conditioner applied to a gasoline vehicle, and the refrigerant / coolant heat exchanger is added to the original cooling refrigeration cycle. Refrigerant circuits and devices that have the same pressure condition by connecting the minimum heating circuit such as the first heating circuit, the second expansion valve, and the second heating circuit provided with the outside evaporator to the device Since the heat pump cycle for heating can be configured by sharing the heat, a vehicle that is applied to current gasoline vehicles without newly developing a refrigerant circuit or HVAC unit with pressure specifications that can withstand both cooling and heating operations Refrigerant circuits and equipment that have the same pressure conditions as the cooling cycle of the air conditioner for air conditioning are shared, and the minimum heating circuits and equipment with different pressure conditions are added. Simply, it is possible configurations excellent low cost and mountability relatively simple, provides a heat pump air-conditioning system highly efficient reliability can be suitably applied to an electric vehicle or a hybrid vehicle, or the like. Moreover, even if the outside evaporator is frosted, efficient heat pump heating operation can be continued as it is, so that the heating operation interruption and power consumption loss due to switching to the defrosting operation during heating operation are eliminated. be able to.

It is a refrigerant circuit figure of the heat pump type vehicle air conditioner concerning one embodiment of the present invention. It is a refrigerant circuit diagram which shows the refrigerant | coolant flow at the time of air_conditioning | cooling of the heat pump type vehicle air conditioner shown in FIG. It is a refrigerant circuit diagram which shows the refrigerant | coolant flow at the time of engine exhaust heat heating of the heat pump vehicle air conditioner shown in FIG. It is a refrigerant circuit figure which shows the refrigerant | coolant flow at the time of heat pump heating of the heat pump type vehicle air conditioner shown in FIG. It is a refrigerant circuit diagram which shows the refrigerant | coolant flow at the time of frost formation to the external evaporator of the heat pump type vehicle air conditioner shown in FIG. It is a block diagram of the control apparatus which controls the heat pump type vehicle air conditioner shown in FIG. FIG. 7 is an operation control flowchart by the control device shown in FIG. 6. It is a control flow figure at the time of the cooling operation control by the control apparatus shown in FIG. It is a partial figure of the control flowchart at the time of heating operation control by the control apparatus shown in FIG. FIG. 7 is another partial diagram of a control flow diagram during heating operation control by the control device shown in FIG. 6. FIG. 7 is another partial diagram of a control flow diagram during heating operation control by the control device shown in FIG. 6. It is a control flow figure at the time of the defrost operation control by the control apparatus shown in FIG.

In the following, an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a refrigerant circuit diagram of a heat pump vehicle air conditioner according to an embodiment of the present invention.
The heat pump type vehicle air conditioner 1 according to the present embodiment includes an HVAC unit (Heating Ventilation and Air Conditioning Unit) 2, a heat pump cycle 3 capable of cooling and heating, and a heater core 10 of the HVAC unit 2, with an engine, a motor, and an inverter. And a coolant circulation circuit 5 that enables circulation of coolant for cooling the vehicle drive device 4 such as the above.

  The HVAC unit 2 switches between the inside air and the outside air from the inside of the vehicle via the inside / outside air switching damper 6 and introduces the blower 7 to be pumped to the downstream side, and the air flow path 8 connected to the blower 7 from the upstream side to the downstream side. An in-vehicle evaporator 9, a heater core 10, and a temperature control damper 11 that are sequentially arranged toward the side are provided. The HVAC unit 2 is installed in an instrument panel in the front of the vehicle, and air that has been temperature-controlled by the vehicle evaporator 9 and the heater core 10 is opened toward the vehicle. From any one of a plurality of air outlets such as the air outlet 14, the air is blown into the vehicle according to the air blowing mode switched by the air blowing mode switching dampers 15, 16 and 17, and the vehicle interior is air-conditioned to a set temperature.

  The heat pump cycle 3 capable of cooling and heating is provided in the HVAC unit 2, the electric compressor 20 that compresses the refrigerant, the outside condenser 21, the receiver 22, the first electromagnetic valve 23 and the first expansion valve 24. The in-vehicle evaporator 9 and the check valve 25 are provided with a closed cycle cooling refrigeration cycle (refrigerant circuit) 27 connected in this order via a refrigerant pipe 26. The cooling refrigeration cycle 27 may be the same as a current vehicle air conditioner applied to a gasoline vehicle.

  In the heat pump cycle 3, the coolant that circulates in the coolant circulation circuit 5 to the discharge pipe (discharge circuit) 26 </ b> A from the electric compressor 20 with respect to the cooling refrigeration cycle 27 that is the original form, and the electric compressor 20 A refrigerant / coolant heat exchanger 28 for exchanging heat with the hot gas refrigerant discharged from is provided. Further, a three-way switching valve (switching means) 29 is provided in the inlet-side refrigerant pipe 26 </ b> B of the outside condenser 21, and the refrigerant condensed in the refrigerant / coolant heat exchanger 28 via the three-way switching valve 29 is supplied to the receiver 22. A first heating circuit 30 is connected. Further, a second electromagnetic valve 31, a second expansion valve 32, an outside evaporator 33, and a check valve 34 are sequentially arranged between the outlet refrigerant pipe 26D of the receiver 22 and the suction pipe 26E to the electric compressor 20. A provided second heating circuit 35 is connected.

  Thus, the electric compressor 20, the refrigerant / coolant heat exchanger 28, the three-way switching valve 29, the first heating circuit 30, the receiver 22, the second electromagnetic valve 31, the second expansion valve 32, and the evaporation outside the vehicle. A closed-cycle heating heat pump cycle (refrigerant circuit) 36 is configured in which the heater 33 and the second heating circuit 35 provided with the check valve 34 are connected in this order via the refrigerant pipe 26. The three-way switching valve 29 may be replaced with a configuration in which two electromagnetic valves are combined.

  In the heat pump cycle 3, the outside-vehicle evaporator 33 that constitutes the heating heat pump cycle 36 is disposed downstream of the outside fan 37 that ventilates outside air to the outside-condenser 21 that constitutes the cooling refrigeration cycle 27. The outside fan 37 is installed in parallel with the outside condenser 21 to share the outside fan 37. Further, a radiator 40 that dissipates heat of the coolant that has cooled the vehicle driving device 4 such as an engine, a motor, and an inverter is installed on the downstream side of the outside condenser 21, and the outside evaporator 33 is disposed downstream of the radiator 40. It is installed on the side. A plurality of radiators 40 may be provided independently for engine cooling, motor and inverter cooling.

  Further, as shown in FIG. 1, the receiver 22 of the present embodiment includes check valves 38, respectively, at two refrigerant inlets to which the refrigerant pipe 26 </ b> C and the first heating circuit 30 are connected from the outside condenser 21. 39 is a receiver 22 with a check valve integrated therein.

  Further, the coolant circulation circuit 5 cools the vehicle drive equipment (engine, motor, inverter, etc.) 4 and increases the temperature of the coolant in parallel with the refrigerant / coolant heat exchanger 28 and heater core 10 side and the radiator 40 side. It can be circulated. The coolant circulation circuit 5 is provided with a coolant pump 41 and a three-way control valve 42, and the flow rate of coolant flowing through the refrigerant / coolant heat exchanger 28 and heater core 10 side and the radiator 40 side according to the temperature of the coolant. Automatic adjustment is possible.

  In the present embodiment, temperature-type automatic expansion valves are used as the first expansion valve 24 and the second expansion valve 32, and the first electromagnetic valve 23 and the second electromagnetic valve that open and close the refrigerant circuit on the respective inlet sides. The valve 31 is provided. However, the first electromagnetic valve 23 and the first expansion valve 24, and the second electromagnetic valve 31 and the second expansion valve 32 are replaced with a configuration in which one electronic expansion valve having the function of an on-off valve is installed. May be.

Next, the flow of the refrigerant and the coolant during operation of the heat pump vehicle air conditioner 1 will be described with reference to FIGS. In each figure, the refrigerant and coolant flow paths during operation are indicated by bold lines.
[Cooling and dehumidifying heating]
During the cooling and dehumidifying heating operation, the refrigerant compressed by the electric compressor 20 passes through the refrigerant / coolant heat exchanger 28 and the three-way switching valve 29 from the discharge pipe 26A as shown in FIG. The heat is exchanged with the outside air that is circulated through the vehicle and is passed through the outside fan 37 to be condensed and liquefied. The liquid refrigerant is introduced into the receiver 22 via the refrigerant pipe 26C and the check valve 38, and once stored, the liquid refrigerant is led to the first expansion valve 24 via the refrigerant pipe 26D and the first electromagnetic valve 23, Here, the pressure is reduced to a gas-liquid two-phase state, and the gas-liquid two-phase state is supplied to the in-vehicle evaporator 9.

  The refrigerant that has been heat exchanged with the inside air or outside air (inside air during dehumidification heating) blown from the blower 7 by the in-vehicle evaporator 9 is evaporated into an electric compressor via a check valve 25 from an intake pipe 26E. 20 is inhaled and recompressed. Thereafter, the same cycle is repeated. This cooling cycle 27 is the same as the cooling cycle of the current vehicle air conditioner applied to gasoline vehicles, and can be shared as it is. The inside air or the outside air cooled by heat exchange with the refrigerant in the in-vehicle evaporator 9 is supplied to the def outlet 12, the face outlet 13, according to the blowing mode switched by the blowing mode switching dampers 15, 16, 17. The air is blown into the vehicle from any one of the foot outlets 14 and used for cooling the vehicle interior.

  At the maximum cooling (MAX COOL), the air flow to the heater core 10 is blocked by the temperature control damper 11, and the cold air cooled by the in-vehicle evaporator 9 is blown into the vehicle as it is. Further, by operating the cooling cycle 27, the temperature control damper 11 provided at the inlet of the heater core 10 is opened, and a part of the cool air cooled by the in-vehicle evaporator 9 is passed through the heater core 10 to be reheated. Temperature control can be performed.

  On the other hand, at the time of dehumidifying heating, the cold air cooled by the in-vehicle evaporator 9 is heated by the heater core 10 to be dehumidified warm air, and this is changed according to the blowing mode switched by the blowing mode switching dampers 15, 16, 17. The air can be blown into the vehicle from any one of the differential air outlet 12, the face air outlet 13, and the foot air outlet 14, and used for dehumidifying heating in the vehicle interior. During this dehumidifying and heating operation, the coolant pump (water pump) 41 of the coolant circulation circuit 5 is operated, and the coolant that has been heated by cooling the vehicle driving device 4 is heated by the refrigerant / coolant heat exchanger 28. It is further heated by the refrigerant and circulated through the heater core 10.

[Exhaust heat heating]
When exhaust heat from the vehicle drive device 4 side such as an engine, a motor and an inverter is sufficiently secured, the operation on the heat pump cycle 3 side is stopped and the coolant pump of the coolant circulation circuit 5 is stopped as shown in FIG. By operating only 41, exhaust heat heating operation can be performed. In this case, the coolant that has been heated by cooling the vehicle drive device 4 is circulated to the heater core 10 by the coolant pump 41 via the refrigerant / coolant heat exchanger 28. The coolant that has exchanged heat with the outside air or the inside air from the blower 7 in the heater core 10 and circulates in a path that returns to the vehicle drive device 4 via the three-way control valve 42, and heats the outside air or the inside air for heating. Provided.

[Heat pump heating (before frost formation)]
During the heat pump heating operation, until the outside evaporator 33 is frosted, the hot gas refrigerant compressed by the electric compressor 20 is refrigerant / coolant heat exchanged by the discharge pipe 26A as shown in FIG. In this case, the heat is dissipated into the coolant circulating in the coolant circulation circuit 5 and condensed. The liquid refrigerant is guided to the first heating circuit 30 via the three-way switching valve 29 and is introduced into the receiver 22 via the check valve 39. The refrigerant once stored in the receiver 22 is guided to the second heating circuit 35 through the refrigerant pipe 26D, and is reduced in pressure in the process of passing through the second expansion valve 32 through the second electromagnetic valve 31, whereby the gas-liquid A phase state is established and supplied to the outside evaporator 33.

  The refrigerant supplied to the outside evaporator 33 is subjected to heat exchange with the outside air ventilated by the outside fan 37 in the outside evaporator 33 and is converted into evaporative gas by absorbing heat from the outside air. It is sucked into the electric compressor 9 from 26E and recompressed. Thereafter, the same cycle is repeated, and the coolant heated by the refrigerant / coolant heat exchanger 28 is circulated through the coolant circulation circuit 5 to the heater core 10 by the heating heat pump cycle 35, and the heater core 10 from the blower 7. Heat pump heating operation is performed by heating the outside air or the inside air that is blown.

  In this way, the refrigerant / coolant heat exchanger 28 and the three-way switching valve 29 provided on the inlet side of the external condenser 21 are connected to the discharge pipe (discharge circuit) 26A of the cooling refrigeration cycle 27 which is the original form, and the receiver 22. Between the first heating circuit 30 and between the outlet side of the receiver 22 and the suction side of the electric compressor 20, a second electromagnetic valve 31, a second expansion valve 32, and an outside evaporator 33 are provided. By connecting a minimum heating circuit and equipment such as the heating circuit 35, the heating heat pump cycle 36 can be configured by sharing circuit portions and equipment having the same pressure condition.

[Heat pump heating (after frost formation)]
As described above, when the outside evaporator 33 is made to function as an evaporator and heat is absorbed from the outside air to perform a heating operation, frost forms on the surface of the outside evaporator 33 at a low outside temperature, and as frost formation proceeds. There is a risk that the heating capacity will decline and it will become impossible to heat. For this reason, in this embodiment, when frost formation is detected with respect to the outside evaporator 33, as FIG. 5 shows, the 1st solenoid valve 23 is opened and the 2nd solenoid valve 31 is closed, and it evaporates inside a vehicle. Switching to the heat pump heating cycle 36 using the vessel 8 is made.

  In this case, the hot gas refrigerant discharged from the electric compressor 20 is first introduced into the refrigerant / coolant heat exchanger 28 through the discharge pipe 26A, as in the heating operation before frosting. Heat is condensed to the circulating coolant. The liquid refrigerant is guided to the first heating circuit 30 via the three-way switching valve 29 and is introduced into the receiver 22 via the check valve 39. The refrigerant once stored in the receiver 22 is guided to the first expansion valve 24 via the refrigerant pipe 26D and the first electromagnetic valve 23, and is decompressed to be in a gas-liquid two-phase state and supplied to the in-vehicle evaporator 9. .

  In the in-vehicle evaporator 9, the refrigerant that has been heat exchanged with the inside air blown from the blower 7 and converted into evaporated gas is sucked into the electric compressor 20 via the check valve 25 and the suction pipe 26E, and is recompressed. The Thereafter, the same cycle is repeated. During this time, the air (inside air) cooled and dehumidified by being absorbed by the refrigerant in the in-vehicle evaporator 9 is heated by the heater core 10 installed on the downstream side of the in-vehicle evaporator 9 as described above, and the def outlet 12, By being blown into the vehicle from either the face blow-out port 13 or the foot blow-out port 14, the vehicle is heated.

  As described above, after frosting on the outside evaporator 33, switching to the dehumidifying and heating operation using the inside evaporator 9 as an evaporator and circulating the coolant heated by the refrigerant / coolant heat exchanger 28 to the heater core 10. Thus, the heating operation can be continued. Further, the heating operation after frost formation on the outside evaporator 33 is a dehumidifying heating operation. For this reason, it is not necessary to worry about the fogging of the window, and the heating capacity can be increased by switching to the inside air circulation mode and absorbing heat from the high-temperature air by the in-vehicle evaporator 9.

[Defrost]
Even when the outside evaporator 33 is functioning and performing the heating operation, even if the outside evaporator 33 is frosted, it is not defrosted immediately, but by switching to the dehumidifying and heating operation using the inside evaporator 9, the heating is performed as it is. Continue to drive. Thus, in this embodiment, the forced defrost operation which interrupted heating operation is not performed, and it defrosts by the following, performing heating operation.

  When the outside air temperature is not below freezing, the outside fan 37 is driven by natural wind or if necessary, the outside air is ventilated through the outside evaporator 33, the natural air is defrosted by the outside air, and when the defrosting is completed, the outside evaporator 33 is It is made to return to the heating operation used. On the other hand, when the outside air temperature is below the freezing point, natural defrost is difficult. Therefore, as shown in FIG. 5, a part of the coolant that has been heated by cooling the vehicle driving device 4 is passed through the coolant circulation circuit 5. The air is circulated through the radiator 40 to dissipate heat to the outside air, and the outside air heated by the heat is blown to the outside evaporator 33 provided on the downstream side of the radiator 40 to defrost.

  As described above, when frost forms on the outside evaporator 33, switching to the inside evaporator 9 and continuing the heating operation by the dehumidifying heating operation, the frost formation on the outside evaporator 33 is utilized by the natural defrost or the heat radiation from the radiator 40. By defrosting and returning to the heating operation using the outside evaporator 33 at the time when each defrost is completed, the defrost can be efficiently and effectively performed.

  Each of the above operations is controlled via the air conditioning controller 50 shown in FIG. The control device 50 is connected to a host-side control device 51 on the vehicle side, and related information can be input from the vehicle side. The control device 50 also includes a control panel 52, and includes detection signals from the following sensor groups, Based on input information from the control device 51 and the control panel 52, operation control of the vehicle air conditioner 1 is performed.

  The control device 50 includes an in-vehicle temperature sensor (Tr) 53, an outside air temperature sensor (Tamb) 54, a solar radiation sensor (Ts) 55, a vehicle speed sensor 56, and a vehicle speed sensor 56 that are installed at appropriate positions of the vehicle. A frost sensor (FS) 57 installed in the in-vehicle evaporator 9, an out-of-vehicle evaporator refrigerant temperature sensor (T1) 58 installed in the out-of-vehicle evaporator 33, and a high pressure sensor (HP) 59 installed in the discharge pipe 26A. Detection signals from a heater core blowing temperature sensor (Tc) 60, a coolant temperature sensor 61, an outside-vehicle evaporator fin temperature sensor (Tf) 62, and the like installed in the heater core 10 are input.

  Based on the detection signals from the sensors 53-62 and the input information from the control panel 52 and the host control device 51, the control device 50 performs necessary calculations, processes, etc. according to a preset program, Actuator 63 for blowout mode switching dampers 15, 16, and 17, Actuator 64 for inside / outside air switching damper 6, Actuator 65 for temperature control damper 11, motor 66 for blower 6, motor 67 for outside fan 37, electric compression A motor 68 for the machine 20, a motor 69 for the coolant pump 41, an electromagnetic coil 70 for the three-way switching valve 29, an electromagnetic coil 71 for the electromagnetic valves 23 and 31, a motor 72 for the three-way control valve 42, etc. As described above, the vehicle air-conditioning apparatus 1 has a function of controlling the operation.

Below, the operation control of the vehicle air conditioner 1 by this control apparatus 50 is demonstrated with reference to the flowchart shown in FIG. 7 thru | or FIG.
FIG. 7 is a main control flow diagram of the vehicle air conditioner 1. When control is started, first, in step S1, the setting of the control panel 52 is read, and in step S2, detection from each sensor 53-62. Read the value. Based on these set values and detection values, the target blowout temperature Ttar is calculated in step S3, and the process proceeds to step S4. Here, it is determined whether or not there is a dehumidifying operation. If “YES”, the process proceeds to step S5 to enter “cooling operation control”, and if “NO”, the process proceeds to step S6 and “heating operation”. Enter control. Thereafter, in step S7, the detection value of each sensor 53-62 is output, and the process returns to the start point.

  When “cooling operation control” is entered in step S5, the process proceeds to the cooling operation control shown in FIG. In the cooling operation control, first, in step S10, the flow path of the three-way switching valve 29 is determined, and is connected to a circuit that causes the refrigerant to flow to the outside condenser 21 side. Subsequently, in step S11, the opening / closing of the solenoid valve is determined, the solenoid valve 23 is opened, and the solenoid valve 31 is closed. Thereby, the cooling cycle 27 is set.

  Subsequently, in step S12, the number of rotations of the electric compressor 20, in step S13, a suction mode by switching the inside / outside air switching damper 6, in step S14, a blowing mode by switching the blowing mode switching dampers 15, 16, and 17, step S15. In step S16, the opening degree of the temperature control damper 11, the drive voltage of the blower 7 in step S16, the drive voltage of the outside fan 37, etc. are determined in step S17, and the motors and actuators 63-68, 70, 71 are driven. Thus, the cooling operation is executed so that the in-vehicle temperature becomes the set temperature. Then, it returns to S1 (= step S7) and the cooling operation is continued.

  Further, when “heating operation control” is entered in step S6, the operation is shifted to the heating operation control shown in FIG. 9 and FIG. In the heating operation control, first in step S20, it is determined whether or not the outside air temperature Tamb is equal to or higher than a set value a (for example, a is 0 ° C. of freezing point) (Tamb ≧ a). If “YES”, the process proceeds to step S21. If "NO", the process moves to step S22. In step S21, the flow path of the three-way switching valve 29 is determined and connected to a circuit that causes the refrigerant to flow to the first heating circuit 30 side. Subsequently, in step S23, the opening / closing of the solenoid valve is determined, the solenoid valve 23 is closed, and the solenoid valve 31 is opened. As a result, a heating heat pump cycle 36 before frosting is set which causes the refrigerant to flow to the second heating circuit 35 side, that is, the outside-vehicle evaporator 33.

  Thereafter, the process proceeds to step S24, where the inside / outside air switching damper 6 is determined to be in the outside air introduction mode, and the process proceeds to step S25. In step S25, the presence or absence of frost formation on the outside-vehicle evaporator 33 is determined. This frost formation determination is made based on whether or not the difference between the detection value T1 of the outside-vehicle evaporator refrigerant temperature sensor 58 and the detection value Tamb of the outside air temperature sensor 54 is greater than or equal to a set value a (T1−Tamb ≧ a). If it is determined “YES” (with frost formation), the process proceeds to step S26. If it is determined “NO” (no frost formation), the process proceeds to step S27.

  When the process proceeds to step S27 due to no frost formation, the rotational speed of the electric compressor 20 is determined here. Further, in step S28, the blowing mode is switched by switching the blowing mode switching dampers 15, 16, and 17, in step S29. The opening degree of the temperature control damper 11, the drive voltage of the blower 7 in step S30, the drive voltage of the outside fan 37, etc. are sequentially determined in step S31, and the motors and actuators 63, 65-68 are driven. The heating operation is executed so that the in-vehicle temperature becomes the set temperature. Then, it returns to S1 (= step S7) and heating operation is continued.

On the other hand, when it is determined in step S25 that there is frost formation and the process proceeds to step S26, “defrost operation control” is entered, and defrost operation control is executed as shown in FIG.
In this defrosting operation control, first, in step S80, the flow path of the three-way switching valve 29 is determined and connected to a circuit that causes the refrigerant to flow to the first heating circuit 30 side. Subsequently, in step S81, the opening / closing of the solenoid valve is determined, the solenoid valve 23 is opened, the solenoid valve 31 is closed, and the evaporator is switched to the vehicle interior evaporator 9. Is set.

  Subsequently, in step S82, the rotational speed of the electric compressor 20, in step S83, the suction mode (in this case, the internal air circulation mode) by switching the inside / outside air switching damper 4, and in step S84, the blow-out mode switching dampers 15, 16, 17 are used. In step S85, the opening degree of the temperature control damper 11, the driving voltage of the blower 7 in step S86, the driving voltage of the outside fan 37 in step S87, and the like are sequentially determined, and the motor and actuator 63-68. Is driven, the dehumidifying and heating operation using the in-vehicle evaporator 9 is performed so that the in-vehicle temperature becomes the set temperature.

  In this way, while the defrosting operation is controlled, the air conditioner 1 is operated in the dehumidifying and heating operation, and the frost that has been frosted on the outside evaporator 33 during this time is caused by natural air or outside air that is passed through the outside fan 37. Defrosted naturally. When the defrosting operation control is completed, the process returns to S2 (= step S32), where it is determined whether or not the detected value of the outside evaporator fin temperature sensor (Tf) 62 is equal to or less than the set value b (Tf <b). Determined. In the case of “YES”, it is determined that the defrost is not completed, the process returns to step S26, and the defrosting operation control is continued. Further, in the case of “NO”, the process proceeds to step S33 and the defrosting operation control is ended. Then, it returns to S1 (= step S7) and heating operation is continued.

  On the other hand, if it is determined “NO” in step S20 and the process proceeds to step S22, whether or not the coolant temperature (or water temperature) Tw detected by the coolant temperature sensor 61 is equal to or less than the set value c. (Tw <c) is determined. If the coolant temperature Tw is very high and it is determined as “NO”, the process proceeds to step S34, the engine of the vehicle drive device 4 is turned off, and the coolant pump (water pump) 41 is turned off in step S35. In step S36, the electric compressor 20 is turned off. Subsequently, the blow mode by switching the blow mode switching dampers 15, 16, and 17 is determined in step S37, the opening degree of the temperature control damper 11 is determined in step S38, the drive voltage of the blower 7 is determined in step S39, and the motors and actuators 63 and 65 are determined. 66 are driven. Thereby, exhaust heat heating is performed.

  If “YES” is determined in the step S22, the process proceeds to a step S40 to determine whether or not the coolant temperature Tw is equal to or higher than a set value d (Tw> d). If the coolant temperature Tw is very low and the determination is “NO”, the process proceeds to step S41. If the coolant temperature Tw is equal to or greater than the set value d, the determination is “YES” and the process proceeds to step S42. In step S42, the flow path of the three-way switching valve 29 is determined and connected to a circuit that causes the refrigerant to flow to the first heating circuit 30 side. Subsequently, in step S43, the opening / closing of the solenoid valve is determined, the solenoid valve 23 is closed, and the solenoid valve 31 is opened. Thus, the heating heat pump cycle 36 before frosting that causes the refrigerant to flow to the outside evaporator 33 is set. Is set.

  Thereafter, the process proceeds to step S44, where the inside / outside air switching damper 6 is determined to be in the outside air introduction mode, and the process proceeds to step S45. In step S45, the presence or absence of frost formation on the outside evaporator 33 is determined. This frost formation determination is made based on whether or not the difference between the detected value T1 of the outside evaporator refrigerant temperature sensor 58 and the detected value Tamb of the outside air temperature sensor 54 is greater than or equal to a set value e (T1−Tamb ≧ e). If it is determined “YES” (with frost formation), the process proceeds to step S46. If it is determined “NO” (no frost formation), the process proceeds to step S47.

  If it is determined in step S45 that there is no frost formation and the process proceeds to step S47, the engine of the vehicle drive device 4 is turned off. In step S48, the coolant pump (water pump) 41 is turned off. Subsequently, in step S49, the rotational speed of the electric compressor 20, in step S50, the blowing mode by switching the blowing mode switching dampers 15, 16, and 17, in step S51, the opening of the temperature adjustment damper 11, in step S52, In step S53, the driving voltage of the blower 7, the driving voltage of the outside fan 37, etc. are determined, and the motor and the actuators 63, 65-68 are driven to execute the heating operation so that the in-vehicle temperature becomes the set temperature. Is done. Then, it returns to S1 (= step S7) and heating operation is continued.

  If it is determined in step S45 that frost formation has occurred and the process proceeds to step S46, the engine of the vehicle drive device 4 is turned on. In step S54, the coolant pump (water pump) 41 is turned on. Then, it transfers to step S55 and enters "defrost operation control", and defrost operation control is performed as FIG. In addition, this defrost operation control is as above-mentioned, and abbreviate | omits description. On the other hand, during the defrosting operation control, since the engine of the vehicle drive device 4 and the coolant pump 41 are turned on, the coolant whose temperature has been raised by the exhaust heat of the engine is circulated to the radiator 40 and radiates heat to the outside air. Is done. Therefore, the frost of the outside evaporator 33 can be efficiently defrosted using the warm air heated by the heat.

  When the defrosting operation control ends, the process returns to S2 (= step S56), and it is determined whether or not the detected value of the outside-vehicle evaporator fin temperature sensor (Tf) 62 is equal to or less than the set value b (Tf <b). When it is determined as “YES”, it is determined that the defrost is not completed, the process returns to step S55, and the defrosting operation control is continued. Moreover, when it determines with "NO", it transfers to step S57 and a defrost operation control is complete | finished. Then, it transfers to S1 (= step S7) and heating operation is continued.

  Furthermore, in step S40, when the coolant temperature Tw is very low and it is determined as “NO” and the process proceeds to step S41, the engine of the vehicle drive device 4 is turned on, and then in step S58. The coolant pump (water pump) 41 is turned on. Next, in step S59, the flow path of the three-way switching valve 29 is determined and connected to a circuit for flowing the refrigerant to the first heating circuit 30 side. In step S60, the opening / closing of the solenoid valve is determined, the solenoid valve 23 is closed, and the solenoid valve 31 is opened. Thereby, the heat pump cycle 36 for heating before frost formation which flows a refrigerant | coolant to the evaporator 33 outside a vehicle is set.

  Thereafter, the process proceeds to step S61, where the inside / outside air switching damper 6 is determined to be in the outside air introduction mode, and the process proceeds to step S62. In step S62, the presence or absence of frost formation on the outside-vehicle evaporator 33 is determined. This frost formation determination is made based on whether or not the difference between the detected value T1 of the outside evaporator refrigerant temperature sensor 58 and the detected value Tamb of the outside air temperature sensor 54 is equal to or greater than a set value e (T1−Tamb ≧ e). If it is determined as “YES” (with frost formation), the process proceeds to step S63. If it is determined as “NO” (without frost formation), the process proceeds to step S64.

  If it is determined in step S62 that there is no frost formation and the process proceeds to step S64, the rotational speed of the electric compressor 20 is determined here. Subsequently, in step S65, the blowing mode is switched by switching the blowing mode switching dampers 15, 16, and 17. In step S66, the opening degree of the temperature control damper 11, in step S67, the drive voltage of the blower 7, and in step S68, the outside fan. The driving voltage and the like of 37 are sequentially determined, and the motor and actuators 63 and 65-68 are driven, so that the heating operation is performed so that the in-vehicle temperature becomes the set temperature. Then, it returns to S1 (= step S7) and heating operation is continued.

  If it is determined in step S62 that there is frost formation, the process proceeds to step S63 to enter "defrosting operation control", and the defrosting operation control is executed as shown in FIG. This defrosting operation control is as described above, and a description thereof is omitted. On the other hand, during this defrosting operation control, since the engine of the vehicle drive device 4 and the coolant pump 41 are on, the coolant whose temperature has been raised by the exhaust heat of the engine is circulated to the radiator 40 and radiated to the outside air. Is done. Therefore, the frost of the outside evaporator 33 can be efficiently defrosted using the warm air heated by the heat.

  When the defrosting operation control is completed, the process returns to S2 (= step S69), and it is determined whether or not the detected value of the outside evaporator fin temperature sensor (Tf) 62 is equal to or less than the set value b (Tf <b). When it is determined as “YES”, it is determined that the defrost is not completed, the process returns to step S63, and the defrosting operation control is continued. Moreover, when it determines with "NO", it transfers to step S70 and a defrost operation control is complete | finished. Then, it transfers to S1 (= step S7) and heating operation is continued.

Thus, according to the present embodiment, the following operational effects are achieved.
According to the heat pump type vehicle air conditioner 1 of the present embodiment, the vehicle interior evaporator 9, the heater core 10, the temperature control damper 11, and the like are sequentially disposed in the air flow path 8 from the blower 7. As an HVAC unit 2 that air-conditions the interior of a vehicle by blowing the air temperature-controlled at 10 into any of a plurality of outlets provided on the downstream side thereof, the present invention is applied to an air conditioner for a current gasoline vehicle. The HVAC unit can be applied with substantially the same configuration.

  Further, the cooling system includes an electric compressor 20, an external condenser 21, a receiver 22, a first expansion valve 24, an in-vehicle evaporator 9 provided in the HVAC unit 2, and the like, which are applied to an existing air conditioning system for gasoline vehicles. The minimum heating circuit such as the second heating circuit 35 including the refrigerant / coolant heat exchanger 28, the first heating circuit 30, the second expansion valve 32, and the outside-vehicle evaporator 33 with respect to the refrigeration cycle 27. And by connecting the devices, the refrigerant circuit and the devices having the same pressure condition can be shared, and the heat pump cycle 36 for heating can be configured.

  Therefore, without newly developing a heat pump and an HVAC unit that can withstand both cooling and heating operations, a refrigerant circuit that has the same pressure condition as the cooling cycle of the current vehicle air conditioner applied to a gasoline vehicle, By simply sharing equipment and adding a minimum heating circuit and equipment with different pressure conditions, the configuration is relatively simple, low cost, excellent mountability, and suitable for use in electric and hybrid vehicles. A highly reliable and highly efficient heat pump type vehicle air conditioner 1 that can be provided can be provided.

  The heating heat pump cycle 36 shuts off the refrigerant flow to the second heating circuit 35 side and flows the refrigerant to the in-vehicle evaporator 9 side when the outside evaporator 33 is frosted at a low outside temperature. Switching to dehumidifying heating using the in-vehicle evaporator 8 is possible. For this reason, at the time of frost formation with respect to the outside evaporator 33, an efficient heat pump heating operation can be continued as it is by switching the evaporator to the in-vehicle evaporator 8 side, and accordingly, switching to the defrosting operation is performed during the heating operation. The interruption of the heating operation and the loss of power consumption due to this can be eliminated.

  Further, when the operation is switched to the dehumidifying and heating operation using the in-vehicle evaporator 9, the operation is performed in the inside air circulation mode. As a heat source, the heat pump heating operation can be performed, and thus the heating capacity can be sufficiently secured. In general, when the outside air temperature is low, the heating operation is performed in the outside air introduction mode in order to prevent the window from being fogged. However, the dehumidifying heating operation using the in-vehicle evaporator 9 allows the window air fogging mode as the inside air circulation mode. Can be prevented.

  In addition, the refrigerant / coolant heat exchanger 28 is configured so that the hot gas refrigerant discharged from the electric compressor 20 and the coolant circulating in the coolant circulation circuit 5 can always exchange heat, so that only during heating operation. In addition, even during the cooling operation or the dehumidifying operation, the operation can be performed while always circulating the high-temperature coolant through the heater core 10. Therefore, even when a blowout temperature change command is suddenly issued from the controller side during the maximum cooling operation, it is possible to instantaneously control the target blowout temperature by controlling the temperature with the temperature control damper 11. It is possible to ensure the responsiveness of the tone control.

  Further, in the present embodiment, the outside evaporator 33 is arranged on the downstream side of the radiator 40 for heat dissipation connected to the outside condenser 21 and / or the coolant circulation circuit 5 in the ventilation path of the outside fan 37 for the outside condenser. In the winter configuration, it is possible to block and reduce snow adhesion and accumulation on the outside-vehicle evaporator 33 by the outside-condenser 21 and / or the radiator 40 even when snowing or accumulating in winter. For this reason, it is possible to prevent the outside evaporator 33 from freezing due to snow adhesion and accumulation, and also to ensure the heat exchange performance by the outside evaporator 33 and improve the heating performance. In addition, when heat is radiated from the radiator 40, the heating capacity can be further improved by absorbing the heat with the outside-vehicle evaporator 33.

  Further, when frost formation is detected on the outside evaporator 33 during heating by the heating heat pump cycle 36, the refrigerant flow to the second heating circuit 35 side is interrupted and the refrigerant flows to the inside evaporator 9 side. When the outside air temperature is equal to or higher than the predetermined value, the outside evaporator 33 is naturally defrosted with the outside air. When the outside air temperature is equal to or lower than the predetermined value, the radiator 40 is heated through the coolant circulation circuit 5. The coolant is circulated to dissipate heat to the outside air, and the outside evaporator 33 is defrosted using the heat.

  For this reason, when frost formation is detected in the outside evaporator 33 during the heating operation under a low outside air temperature, the temperature of the coolant is utilized using the exhaust heat of the vehicle driving device 4 such as the engine, the motor, and the inverter. As a result, it is possible to improve the heating performance and to radiate a part of the heat from the radiator 40, and to efficiently and effectively defrost the outside evaporator 33 using the heated hot air. Therefore, the exhaust heat of the vehicle drive device 4 can be effectively used for heating and defrosting, and power saving can be achieved.

  In addition, this invention is not limited to the invention concerning the said embodiment, In the range which does not deviate from the summary, it can change suitably. For example, in the above-described embodiment, the first electromagnetic valve 23 and the second electromagnetic valve 31 are provided on the inlet side of the first expansion valve 24 and the second expansion valve 32, respectively. The first expansion valve 24, the second electromagnetic valve 31, and the second expansion valve 32 may be configured using a temperature type automatic expansion valve with an electromagnetic opening / closing valve integrated with each other.

  In the above embodiment, the blowing mode switching damper is a three-damper system including the differential damper 15, the face damper 16, and the foot damper 17. However, the differential damper 15 and the face damper 16 are combined with one damper, A two-damper system with the foot damper 17 may be adopted. Furthermore, in the above-described embodiment, the coolant circulation circuit 5 is provided with the three-way control valve 42. The three-way control valve 42 has a flow rate in response to the coolant temperature by a thermo element filled with paraffin wax or the like. It is good also as a thermostat valve which adjusts a ratio automatically. In this case, control of the valve by control device 50 becomes unnecessary.

DESCRIPTION OF SYMBOLS 1 Heat pump type vehicle air conditioner 2 HVAC unit 4 Vehicle drive device 5 Coolant circulation circuit 9 In-vehicle evaporator 10 Heater core 12 Differential outlet 13 Face outlet 14 Foot outlet 20 Electric compressor 21 Outside condenser 22 Receiver 24 First Expansion valve 26A Discharge circuit (Discharge piping)
27 Refrigeration cycle for cooling 28 Refrigerant / coolant heat exchanger 29 Three-way switching valve (switching means)
30 First heating circuit 32 Second expansion valve 33 Outside evaporator 35 Second heating circuit 36 Heating heat pump cycle 37 Outside fan 40 Radiator

Claims (4)

An HVAC unit that includes an in-vehicle evaporator and a heater core, and blows air temperature-adjusted by the in-vehicle evaporator and the heater core into a vehicle from any one of a plurality of outlets provided downstream thereof; ,
A coolant circulation circuit capable of circulating coolant for cooling a vehicle driving device such as an engine, a motor and an inverter with respect to the heater core;
An electric compressor, an external condenser, a receiver, a first expansion valve, a cooling cycle for cooling in which the in-vehicle evaporator is connected in this order;
A refrigerant / coolant heat exchanger provided in a discharge pipe of the electric compressor, for exchanging heat between the hot gas refrigerant and the coolant circulating in the coolant circulation circuit;
A first heating circuit connected to the receiver via switching means provided on the inlet side of the external condenser;
A second heating circuit connected between the outlet side of the receiver and the suction side of the electric compressor and provided with a second expansion valve and an outside evaporator,
For heating by the second heating circuit comprising the electric compressor, the refrigerant / coolant heat exchanger, the switching means, the first heating circuit, the receiver, the second expansion valve and the outside evaporator. A heat pump cycle is configured to allow circulation of the coolant heated by the refrigerant / coolant heat exchanger to the heater core;
During the heating by the heating heat pump cycle, when frost formation is detected for the outside evaporator, the refrigerant flow to the second heating circuit side is interrupted and the refrigerant is circulated to the in-vehicle evaporator side, A heat pump type vehicle air conditioner that can be switched to dehumidifying heating using the in-vehicle evaporator.   The refrigerant / coolant heat exchanger is configured to always exchange heat between the hot gas refrigerant discharged from the electric compressor and the coolant circulating in the coolant circulation circuit. The heat pump type vehicle air conditioner according to 1.   The outside-vehicle evaporator is disposed downstream of a radiator for heat dissipation connected to the outside-condenser and / or the coolant circulation circuit in a ventilation path of the outside fan for the outside-condenser. The heat pump type vehicle air conditioner according to claim 1 or 2. During the heating by the heating heat pump cycle, when frost formation is detected for the outside evaporator, the refrigerant flow to the second heating circuit side is interrupted and the refrigerant is circulated to the in-vehicle evaporator side, When heating is continued and the outside air temperature is equal to or higher than a predetermined value, the outside evaporator is naturally defrosted with outside air, and when the outside air temperature is equal to or lower than the predetermined value, the radiator is heated through the coolant circulation circuit. The heat pump type vehicle air conditioner according to claim 3, wherein a coolant is circulated to dissipate heat to the outside air, and the outside evaporator is defrosted by the heat.

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