JP6692659B2 - Vehicle air conditioner - Google Patents

Description

  The present invention relates to a heat pump type air conditioner that air-conditions a passenger compartment of a vehicle, and particularly to an air conditioner applicable to a hybrid vehicle or an electric vehicle.

  With the emergence of environmental problems in recent years, hybrid vehicles and electric vehicles have come into widespread use. Then, as an air conditioner that can be applied to such a vehicle, a compressor that compresses and discharges a refrigerant, a radiator that is provided inside the vehicle interior to radiate the refrigerant, and an interior side of the vehicle interior are provided. A heat absorber that absorbs the refrigerant, an outdoor heat exchanger that is provided outside the vehicle compartment to radiate or absorb the refrigerant, an outdoor expansion valve that decompresses the refrigerant flowing into the outdoor heat exchanger, and a plurality of refrigerant flow switches A solenoid valve is provided, and by controlling these solenoid valves, the refrigerant discharged from the compressor dissipates heat in the radiator, and the refrigerant dissipated in this radiator absorbs heat in the outdoor heat exchanger. The discharged refrigerant is radiated by the radiator, and the refrigerant radiated by the radiator is absorbed by only the heat absorber, or this heat absorber and the outdoor heat exchanger. A dehumidifying and cooling mode in which the generated refrigerant is radiated in the radiator and the outdoor heat exchanger and is absorbed in the heat absorber, and a cooling mode in which the refrigerant discharged from the compressor is radiated in the outdoor heat exchanger and is absorbed in the heat absorber. What is switched and executed has been developed (for example, see Patent Document 1).

  In the case of Patent Document 1, a circuit for dehumidification (refrigerant pipe 13F of Patent Document 1) that bypasses the series circuit of the outdoor expansion valve and the outdoor heat exchanger is provided, and in the dehumidification heating mode, the refrigerant that has passed through the radiator is The flow is divided into the outdoor expansion valve and the dehumidifying circuit, and the heat is absorbed by the heat absorber and the outdoor heat exchanger. In this dehumidification heating mode, the compressor is controlled based on the pressure (high pressure) of the radiator to adjust the heating by the radiator, and the opening degree of the outdoor expansion valve is controlled based on the temperature of the heat absorber. Therefore, the amount of refrigerant absorbed by the heat absorber was adjusted.

  On the other hand, instead of the dehumidifying circuit that bypasses the outdoor expansion valve and the outdoor heat exchanger as described above, a pipe that bypasses the internal condenser that corresponds to the radiator and the first expansion valve that corresponds to the outdoor expansion valve is provided. Have also been developed (see, for example, Patent Document 2).

  In that case, a compressor that compresses and discharges the refrigerant, an internal condenser that is provided inside the vehicle interior to radiate the refrigerant, an evaporator that is provided inside the vehicle interior to absorb the refrigerant, and an outside of the vehicle interior. An external condenser provided for radiating or absorbing heat of the refrigerant, a first expansion valve for expanding the refrigerant flowing into the external condenser, a second expansion valve for expanding the refrigerant flowing into the evaporator, an internal condenser and A pipe that bypasses the first expansion valve and a first valve that switches between flowing the refrigerant discharged from the compressor to the internal condenser or the pipe that bypasses the refrigerant are provided. The heating mode in which the discharged refrigerant radiates heat in the internal condenser, and the radiated refrigerant absorbs heat in the external condenser, and the refrigerant discharged from the compressor radiates heat in the internal condenser and radiates heat. A dehumidification mode in which heat is absorbed in the evaporator, and a cooling mode in which the refrigerant discharged from the compressor by switching the first valve is flowed to the external condenser from the bypass pipe rather than the internal condenser to radiate heat and the heat is absorbed in the evaporator are set. I was switching and running.

JP, 2014-94671, A JP, 2013-23210, A

  In the vehicle air conditioner as in each of the above patent documents, when the solenoid valve or the first valve fails, the selected operation mode cannot be realized, and comfortable air conditioning of the vehicle interior cannot be performed. Therefore, conventionally, a failure of the solenoid valve or the like has been realized by a complicated determination method, so that it has been decided that the control becomes complicated. In addition, when there are a plurality of solenoid valves and the like, it may not be possible to identify which solenoid valve is faulty from the abnormal operating state.

  The present invention has been made to solve the conventional technical problems, and an object of the present invention is to provide a vehicle air conditioner that can determine a failure of a solenoid valve relatively easily.

The vehicle air conditioner of the present invention includes a compressor that compresses a refrigerant, an air flow passage through which air to be supplied to the vehicle compartment circulates, and heat that is supplied to the vehicle interior from the air flow passage by radiating the refrigerant. For heat dissipation, a heat absorber for absorbing the heat of the refrigerant to cool the air supplied from the air flow passage into the vehicle interior, an outdoor heat exchanger provided outside the vehicle interior, and a refrigerant flowing into the outdoor heat exchanger An outdoor expansion valve for decompressing the refrigerant, a bypass pipe for bypassing the radiator and the outdoor expansion valve, and allowing the refrigerant discharged from the compressor to directly flow into the outdoor heat exchanger, and for switching the flow of the refrigerant. A plurality of solenoid valves and a control device are provided, and by controlling the solenoid valve by the control device, a plurality of operation modes are switched and executed, and the control device controls the temperature of each part and / or Pressure detection value, if If the operating state becomes an abnormal state that is presumed to be due to a failure of the solenoid valve or the outdoor expansion valve, based on the calculated value obtained from them, set the rotation speed of the compressor to a constant value, and The temperature and / or pressure normal detection value preliminarily measured at the number of revolutions, or by comparing the normal detection value calculated from them with the detection value or the calculated value, the solenoid valve or the outdoor If a similar failure condition occurs due to the failure of a different solenoid valve or outdoor expansion valve while executing a failure confirmation mode that determines the failure of the expansion valve, the solenoid valve or outdoor expansion that may cause the failure condition. It is characterized in that it has a failure valve confirmation mode for determining which one of the valves has a failure, and executes different failure valve confirmation modes according to a plurality of operation modes .

In the vehicle air conditioner according to a second aspect of the present invention, in the above invention, the control device controls the solenoid valve or the outdoor expansion valve that may cause an abnormal state in each of the plurality of operation modes in the failure valve confirmation mode, It is characterized in that which valve has failed is determined according to the change in the detected value in that case .

A vehicle air conditioner according to a third aspect of the present invention includes an auxiliary heating device for heating the air supplied from the air flow passage into the vehicle compartment in each of the above aspects of the invention, and the controller sets a plurality of operation modes from the compressor to the other mode. A heating mode in which the discharged refrigerant is passed through a radiator to dissipate the heat and the released heat is decompressed, and then the outdoor heat exchanger absorbs the heat, and the refrigerant discharged from the compressor is transferred to the outdoor heat exchanger through a bypass pipe. After flowing and radiating heat, decompressing the radiated refrigerant, and then absorbing heat in the heat absorber and dehumidifying and heating mode in which the auxiliary heating device generates heat, and the refrigerant discharged from the compressor is made to flow from the radiator to the outdoor heat exchanger. Dehumidifying and cooling mode in which the heat is dissipated by the heat radiator and the outdoor heat exchanger, the heat-dissipated refrigerant is decompressed, and then the heat is absorbed by the heat absorber. Flow through the outdoor heat exchanger to radiate the heat, reduce the pressure of the radiated refrigerant, and then absorb the heat in the heat absorber, and the refrigerant discharged from the compressor is circulated to the outdoor heat exchanger through the bypass pipe to radiate the heat. Then, after decompressing the refrigerant that has radiated heat, the maximum cooling mode in which the heat is absorbed by the heat absorber, and defrosting the outdoor heat exchanger by flowing the refrigerant discharged from the compressor from the radiator to the outdoor heat exchanger. It has a frost mode and is characterized in that each operation mode is switched and executed by controlling an electromagnetic valve.

  A vehicle air conditioner according to a fourth aspect of the present invention is an electromagnetic valve for heating which allows the refrigerant that has been opened in the heating mode and has flowed out of the outdoor heat exchanger to flow into the compressor, the dehumidifying heating mode, the dehumidifying cooling mode, and the cooling in the above invention. Mode and the cooling solenoid valve that opens in the maximum cooling mode to let the refrigerant from the outdoor heat exchanger flow to the heat absorber, and the dehumidifying and heating mode, and the maximum cooling mode to open the refrigerant discharged from the compressor. A bypass solenoid valve for flowing into the bypass pipe, and a reheat solenoid valve for opening the refrigerant in the heating mode, dehumidifying and cooling mode, cooling mode, and defrosting mode and flowing the refrigerant discharged from the compressor to the radiator were provided. Is characterized by.

  In the vehicle air conditioner according to a fifth aspect of the present invention, in the above-mentioned invention, when the control device is in the heating mode and the discharge pressure of the compressor rises to a predetermined protection stop value, the closing failure of the solenoid valve for reheating and the COP occur. When it is low, the solenoid valve for bypass has a malfunction, when the temperature of the outdoor heat exchanger is high, or when the suction refrigerant temperature of the compressor is equal to the outside air temperature, the solenoid valve for heating has a malfunction and the radiator When the degree of supercooling of the refrigerant is abnormally high, or when the temperature of the radiator does not change from the start of the compressor, the outdoor expansion valve is closed, and the degree of supercooling of the refrigerant in the radiator does not reach the target value. Is characterized by executing the failure confirmation mode by estimating that the outdoor expansion valve is open.

  A vehicle air conditioner according to a sixth aspect of the present invention is the vehicle air conditioner according to the fourth or fifth aspect, wherein the control device is for reheating when the discharge pressure of the compressor rises to a predetermined protection stop value in the defrosting mode. Closed solenoid valve for heating, when the temperature of the outdoor heat exchanger is high, or when the suction refrigerant temperature of the compressor is equal to the outside air temperature.Closed failure of the solenoid valve for heating, supercooling degree of refrigerant in the radiator. It is characterized by executing the failure confirmation mode by presuming that the outdoor expansion valve has a closed failure.

  A vehicle air conditioner according to a seventh aspect of the present invention is the vehicle air conditioner according to any of the fourth to sixth aspects, wherein the control device is for bypass when the discharge pressure of the compressor rises to a predetermined protection stop value in the dehumidifying and heating mode. It is characterized in that the failure confirmation mode is executed assuming that the solenoid valve is in a closed failure.

  According to an eighth aspect of the present invention, there is provided the vehicle air conditioner according to the fourth to seventh aspects, wherein when the control device is in a dehumidifying cooling mode or a cooling mode, when the discharge pressure of the compressor rises to a predetermined protection stop value. It is presumed that the solenoid valve for reheating has a closed failure, the outdoor expansion valve has a closed failure when the radiator is supercooled, and the outdoor expansion valve has an open failure when the radiator temperature does not reach the target value. It is characterized in that the failure confirmation mode is executed.

  A vehicle air conditioner according to a ninth aspect of the present invention is the vehicle air conditioner according to any of the fourth to eighth aspects, wherein the control device is for bypass when the discharge pressure of the compressor rises to a predetermined protection stop value in the maximum cooling mode. The failure determination mode is executed by assuming that the solenoid valve is closed and that the cooling solenoid valve is closed when the suction refrigerant temperature of the compressor is equal to the outside air temperature.

  A vehicle air conditioner according to a tenth aspect of the present invention is the vehicle control device according to any of the fourth to ninth aspects, wherein the control device is a failure valve when the temperature of the heat absorber does not decrease in the maximum cooling mode, the cooling mode or the dehumidifying and cooling mode. In addition to executing the confirmation mode, in this failure valve confirmation mode, the solenoid valve for heating and the solenoid valve for bypass are closed, the solenoid valve for reheat is opened, the valve opening of the outdoor expansion valve is reduced, and in that state. If the temperature of the outdoor heat exchanger decreases, it is determined that the solenoid valve for heating has an open failure, and if the temperature of the outdoor heat exchanger has not decreased, the solenoid valve for cooling has a close failure.

  In the vehicle air conditioner of the invention of claim 11, in the invention of claims 4 to 10, the controller is a failure valve when the discharge pressure of the compressor is equal to the pressure of the radiator in the maximum cooling mode. While executing the definite mode, in this failure valve definite mode, the solenoid valve for bypass is closed, and if the discharge pressure of the compressor does not rise to a predetermined protection stop value in that state, an open failure of the solenoid valve for reheat, When the temperature rises, it is determined that the outdoor expansion valve has an open failure.

  In the vehicle air conditioner of the invention of claim 12, in the inventions of claims 4 to 11, the control device executes the failure valve determination mode when the temperature of the heat absorber does not decrease in the dehumidification heating mode, In this failure valve confirmation mode, the bypass solenoid valve is closed in the first state, and when the compressor discharge pressure does not rise to the predetermined protection stop value in this first state, the reheat solenoid valve is opened. When it is determined that a failure has occurred and the heat generation of the auxiliary heating device is stopped, the second state is reached, and when the discharge pressure of the compressor becomes equal to the pressure of the radiator in this second state, it is determined that the outdoor expansion valve is open. Then, the solenoid valve for heating and the solenoid valve for bypass are closed, the solenoid valve for reheat is opened, and the valve opening degree of the outdoor expansion valve is reduced to the third state. In this third state, the outdoor heat exchanger is opened. If the temperature of the If the reheat solenoid valve, the outdoor expansion valve, and the heating solenoid valve are normal as the first state, the second state, and the third state, it is determined that the cooling solenoid valve is closed. It is characterized by doing.

  A vehicle air conditioner according to a thirteenth aspect of the present invention is characterized in that, in each of the above aspects, the control device executes a predetermined notification operation when the malfunction of the solenoid valve is confirmed.

  According to the present invention, a compressor for compressing a refrigerant, an air flow passage through which air supplied to the vehicle compartment circulates, and a radiator for radiating the refrigerant to heat the air supplied from the air flow passage to the vehicle interior. In order to reduce the pressure of the refrigerant that flows into the outdoor heat exchanger and the heat absorber that absorbs the heat of the refrigerant and cools the air that is supplied from the air flow passage into the vehicle interior, the outdoor heat exchanger that is provided outside the vehicle interior. Outdoor expansion valve, bypass pipes for bypassing the radiator and outdoor expansion valve, and allowing the refrigerant discharged from the compressor to directly flow into the outdoor heat exchanger, and a plurality of solenoid valves for switching the refrigerant flow. In a vehicle air conditioner that switches and executes a plurality of operation modes by controlling a solenoid valve by the control device, the control device controls the temperature and / or the pressure of each part. Detection value, young If the operating state becomes an abnormal state that is presumed to be due to a failure of the solenoid valve or the outdoor expansion valve, based on the calculated value obtained from them, set the rotation speed of the compressor to a constant value, and By detecting the temperature and / or pressure normally detected at the number of revolutions of the normal value, or by comparing the normal calculated value calculated from them with the detected value or the calculated value, the solenoid valve or the outdoor Since the failure confirmation mode for confirming the failure of the expansion valve is executed, by comparing the detected value with the normal detected value or the calculated value with the normal calculated value, the solenoid valve and the outdoor expansion valve can be relatively easily operated. It becomes possible to judge and confirm the failure.

Here, when a similar abnormal state occurs due to a failure of a different solenoid valve or the outdoor expansion valve, which electromagnetic valve has failed or the outdoor expansion valve has failed from the abnormal state. However, in the present invention, when a similar abnormal state occurs due to the failure of a different solenoid valve or outdoor expansion valve in the present invention, the solenoid valve or outdoor expansion that may cause the abnormal state occurs. It has a failure valve confirmation mode that determines which one of the valves is defective, and it also executes different failure valve confirmation modes according to multiple operation modes. , what the solenoid valve has failed, or it is possible to determine whether the outdoor expansion valve is faulty. In particular, the control device controls the solenoid valve or the outdoor expansion valve that may cause an abnormal state in each of the plurality of operation modes in the failure valve confirmation mode, and changes the detection value in that case. By determining which valve has failed according to the above, it becomes possible to accurately determine the failed valve for each operation mode.

  These are equipped with an auxiliary heating device for heating the air supplied into the vehicle compartment from the air flow passage as in the invention of claim 3, and the control device sets the plurality of operation modes to the refrigerant discharged from the compressor to the radiator. The heating mode in which the refrigerant is discharged by radiating the heat to reduce the pressure of the radiated refrigerant, and then the heat is absorbed by the outdoor heat exchanger, and the refrigerant discharged from the compressor is caused to radiate by radiating the refrigerant to the outdoor heat exchanger through the bypass pipe. After decompressing the refrigerant, the heat absorber absorbs heat and the auxiliary heating device generates heat, and the refrigerant discharged from the compressor is passed from the radiator to the outdoor heat exchanger to release the heat from the radiator and the outdoor heat. A dehumidifying and cooling mode in which heat is radiated by an exchanger and the radiated refrigerant is decompressed, and then the heat is absorbed by a heat absorber, and the refrigerant discharged from the compressor is caused to flow from the radiator to the outdoor heat exchanger and the outdoor heat exchanger concerned. To After radiating heat and decompressing the radiated refrigerant, the cooling mode in which the heat is absorbed by the heat absorber, and the refrigerant discharged from the compressor is made to flow through the outdoor heat exchanger through the bypass pipe to radiate the heat, and the radiated refrigerant is decompressed. After that, there is a maximum cooling mode in which the heat is absorbed by the heat absorber, and a defrost mode in which the refrigerant discharged from the compressor is made to flow from the radiator to the outdoor heat exchanger to defrost the outdoor heat exchanger, and the solenoid valve is used. In a vehicle air conditioner that switches and executes each operation mode by controlling, an electromagnetic valve for heating which opens in the heating mode and flows the refrigerant discharged from the outdoor heat exchanger to the compressor as in the invention of claim 4. And a solenoid valve for cooling, which allows the refrigerant discharged from the outdoor heat exchanger to flow into the heat absorber when opened in the dehumidifying heating mode, the dehumidifying cooling mode, the cooling mode, and the maximum cooling mode, the dehumidifying heating mode, and the maximum cooling mode so The refrigerant discharged from the compressor to the bypass pipe and the bypass solenoid valve, and the refrigerant discharged from the compressor that is opened in the heating mode, dehumidifying and cooling mode, cooling mode, and defrosting mode flows to the radiator. It is extremely effective for those provided with a solenoid valve for reheating.

  That is, for example, when the control device is in the heating mode and the discharge pressure of the compressor rises to a predetermined protection stop value in the heating mode, the reheat solenoid valve is closed, and when the COP is low, it is used for bypass. Opening failure of the solenoid valve, when the temperature of the outdoor heat exchanger is high, or when the suction refrigerant temperature of the compressor is equal to the outside air temperature, the solenoid valve for heating fails to close, and the degree of supercooling of the refrigerant in the radiator Is abnormally large, or the temperature of the radiator has not changed since the compressor was started, the outdoor expansion valve closed.If the refrigerant supercooling degree in the radiator does not reach the target value, the outdoor expansion valve opens. By estimating the failure and executing the failure confirmation mode, it becomes possible to accurately determine and confirm the failure of each electromagnetic valve or the outdoor expansion valve in the heating mode.

  When the discharge pressure of the compressor rises to a predetermined protection stop value in the defrosting mode of the control device as in the sixth aspect of the invention, the solenoid valve for reheating has a closed failure and the temperature of the outdoor heat exchanger is high. Or if the compressor suction refrigerant temperature is equal to the outside air temperature, it is presumed that the solenoid valve for heating has a closed failure, and if the radiator has a supercooling degree of the refrigerant, the outdoor expansion valve has a closed failure. By executing the failure confirmation mode by performing the failure confirmation mode, it becomes possible to accurately determine and confirm the failure of each solenoid valve or the outdoor expansion valve in the defrosting mode.

  Further, in the dehumidifying and heating mode of the invention as claimed in claim 7, when the discharge pressure of the compressor rises to a predetermined protection stop value, it is estimated that the bypass solenoid valve is closed and the failure confirmation mode is executed. By doing so, it becomes possible to accurately determine and confirm the failure of the bypass solenoid valve.

  Further, in the dehumidifying cooling mode or the cooling mode of the control device according to the invention of claim 8, when the discharge pressure of the compressor rises to a predetermined protection stop value, the solenoid valve for reheating fails to close, and the refrigerant in the radiator dissipates. It is estimated that the outdoor expansion valve is closed when the degree of subcooling is present, and the outdoor expansion valve is opened when the radiator temperature does not reach the target value. It becomes possible to accurately determine and determine the failure of each solenoid valve or the outdoor expansion valve in the mode.

  Further, when the control device is in the maximum cooling mode and the discharge pressure of the compressor rises to a predetermined protection stop value in the maximum cooling mode as in the invention of claim 9, the solenoid valve for bypass is closed and the suction refrigerant temperature of the compressor is outside air. When the temperature is equivalent to the temperature, it is estimated that the solenoid valve for cooling has a closed fault, and by executing the fault confirmation mode, the fault of each solenoid valve in the maximum cooling mode can be accurately determined and confirmed. Like

  Here, the abnormal state that the temperature of the heat absorber does not decrease in the maximum cooling mode, the cooling mode, or the dehumidifying cooling mode may occur due to the failure of different solenoid valves. Therefore, when the temperature of the heat absorber does not decrease in the maximum cooling mode, the cooling mode, or the dehumidifying and cooling mode, the control device executes the failure valve confirmation mode, and in the failure valve confirmation mode, If the heating solenoid valve and the bypass solenoid valve are closed, the reheat solenoid valve is opened, the valve opening of the outdoor expansion valve is reduced, and if the temperature of the outdoor heat exchanger falls in that state, the solenoid valve for heating. Open failure, and if it does not go down, it will be determined that the cooling solenoid valve is closed, and the abnormal condition that the temperature of the heat absorber will not drop due to the failure of the different solenoid valve in each of the above operation modes In the event of the occurrence of, it becomes possible to determine which solenoid valve has failed.

  An abnormal state in which the discharge pressure of the compressor is equal to the pressure of the radiator can occur due to a failure of the solenoid valve or the outdoor expansion valve. Therefore, when the discharge pressure of the compressor is equal to the pressure of the radiator in the maximum cooling mode, the control device executes the failure valve determination mode, and in the failure valve determination mode, When the bypass solenoid valve is closed and the compressor discharge pressure does not rise to the specified protection stop value in that state, it is determined that the reheat solenoid valve has an open failure, and if it has risen, the outdoor expansion valve has an open failure. Therefore, in the maximum cooling mode, even if there is an abnormal state that may occur due to a failure of the solenoid valve or the outdoor expansion valve, or the discharge pressure of the compressor is equal to the pressure of the radiator, either valve You will be able to determine if your car is out of order.

  Further, abnormal information that the temperature of the heat absorber does not drop in the dehumidifying and heating mode may occur due to a failure of the solenoid valve or the outdoor expansion valve. Therefore, when the temperature of the heat absorber does not decrease in the dehumidifying and heating mode, the control device executes the failure valve confirmation mode and closes the bypass solenoid valve in the failure valve confirmation mode. In the first state, when the discharge pressure of the compressor does not rise to a predetermined protection stop value in this first state, it is determined that the solenoid valve for reheating has an open failure, and the heat generation of the auxiliary heating device is stopped. When the discharge pressure of the compressor becomes equal to the pressure of the radiator in this second state, it is determined that the outdoor expansion valve has an open failure, and the solenoid valve for heating and the solenoid valve for bypass are set. The solenoid valve for reheating is closed, and the opening degree of the outdoor expansion valve is reduced to the third state. If the temperature of the outdoor heat exchanger drops in this third state, the solenoid valve for heating fails. Confirmed, and the first state, the second state and the third state If the reheat solenoid valve, the outdoor expansion valve, and the heating solenoid valve are normal, the failure of the solenoid valve or the outdoor expansion valve in the dehumidification heating mode is confirmed by confirming that the cooling solenoid valve is closed. Even when an abnormal state that may occur due to the cause or the temperature of the heat absorber does not decrease, it is possible to determine which valve is defective.

  Then, when the failure of the solenoid valve or the outdoor expansion valve as described above is confirmed, the control device executes a predetermined notification operation as in the invention of claim 13, whereby the failure of each valve is instructed to the user. It will be possible to warn and prompt prompt action.

It is a block diagram of the air conditioning apparatus for vehicles of one Embodiment to which this invention is applied (heating mode, dehumidification heating mode, dehumidification cooling mode, and cooling mode). It is a block diagram of the electric circuit of the controller of the air conditioning apparatus for vehicles of FIG. It is a block diagram in the MAX cooling mode (maximum cooling mode) of the vehicle air conditioner of FIG. It is a figure explaining the abnormal state estimated to be caused by the failure of the electromagnetic valve or the outdoor expansion valve of the vehicle air conditioner of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a configuration diagram of a vehicle air conditioner 1 of an embodiment of the present invention. A vehicle of an embodiment to which the present invention is applied is an electric vehicle (EV) in which an engine (internal combustion engine) is not mounted, and is driven by driving an electric motor for traveling with electric power charged in a battery. Yes (none are shown), and the vehicle air conditioner 1 of the present invention is also driven by the electric power of the battery. That is, the vehicle air conditioner 1 of the embodiment performs the heating mode by the heat pump operation using the refrigerant circuit in the electric vehicle that cannot be heated by the engine waste heat, and further performs the dehumidification heating mode, the dehumidification cooling mode, the cooling mode, The MAX cooling mode as the maximum cooling mode and each operation mode of the defrosting mode are selectively executed.

  The present invention is not limited to an electric vehicle as a vehicle, but is also applicable to a so-called hybrid vehicle that uses an engine and an electric motor for traveling, and is also applicable to a normal vehicle that is driven by an engine. Needless to say.

  The vehicle air conditioner 1 of the embodiment is for performing air conditioning (heating, cooling, dehumidification, and ventilation) of a vehicle interior of an electric vehicle, and an electric compressor 2 for compressing a refrigerant, and vehicle interior air. Is provided in the air flow passage 3 of the HVAC unit 10 through which air is circulated, and the high-temperature and high-pressure refrigerant discharged from the compressor 2 flows in through the refrigerant pipe 13G to dissipate this refrigerant into the vehicle interior. And an outdoor expansion valve 6 which is an electrically operated valve that decompresses and expands the refrigerant during heating, and a heat exchange between the refrigerant and the outside air that is provided outside the vehicle compartment and functions as a radiator during cooling and as an evaporator during heating. An outdoor heat exchanger 7, an indoor expansion valve 8 including a motor-operated valve for decompressing and expanding the refrigerant, and a heat absorber 9 provided in the air flow passage 3 for absorbing heat from the inside and outside of the vehicle into the refrigerant. And accumulator 12 etc. Are sequentially connected by a refrigerant pipe 13, the refrigerant circuit R is formed.

  The refrigerant circuit R is filled with a predetermined amount of refrigerant and lubricating oil. The outdoor heat exchanger 7 is provided with an outdoor blower 15. The outdoor blower 15 exchanges heat between the outdoor air and the refrigerant by forcibly ventilating the outdoor air through the outdoor heat exchanger 7, whereby the outdoor air is discharged while the vehicle is stopped (that is, the vehicle speed is 0 km / h). The heat exchanger 7 is configured to ventilate outside air.

  Further, the outdoor heat exchanger 7 has a receiver dryer section 14 and a supercooling section 16 sequentially on the downstream side of the refrigerant, and the refrigerant pipe 13A discharged from the outdoor heat exchanger 7 has a dehumidifying heating mode, a dehumidifying cooling mode, a cooling mode, Also, the refrigerant pipe 13B on the outlet side of the subcooling unit 16 is connected to the receiver dryer unit 14 via the electromagnetic valve 17 for cooling that is opened in the MAX cooling mode, and the refrigerant pipe 13B on the outlet side of the supercooling unit 16 is on the inlet side of the heat absorber 9 via the indoor expansion valve 8. It is connected to the. The receiver dryer unit 14 and the supercooling unit 16 structurally form a part of the outdoor heat exchanger 7.

  Further, the refrigerant pipe 13B between the supercooling section 16 and the indoor expansion valve 8 is provided in a heat exchange relationship with the refrigerant pipe 13C on the outlet side of the heat absorber 9, and both constitute an internal heat exchanger 19. Thus, the refrigerant flowing into the indoor expansion valve 8 via the refrigerant pipe 13B is cooled (supercooled) by the low-temperature refrigerant exiting the heat absorber 9.

  Further, the refrigerant pipe 13A exiting from the outdoor heat exchanger 7 is branched into a refrigerant pipe 13D, and the branched refrigerant pipe 13D is connected to the internal heat exchanger via a heating solenoid valve 21 opened in the heating mode. It is connected to the refrigerant pipe 13C on the downstream side of 19. The refrigerant pipe 13C is connected to the accumulator 12, and the accumulator 12 is connected to the refrigerant suction side of the compressor 2. Further, the refrigerant pipe 13E on the outlet side of the radiator 4 is connected to the inlet side of the outdoor heat exchanger 7 via the outdoor expansion valve 6.

  Further, the refrigerant pipe 13G between the discharge side of the compressor 2 and the inlet side of the radiator 4 is opened in the heating mode, the dehumidifying and cooling mode, the cooling mode, and the defrosting mode, and the dehumidifying and heating mode and the MAX cooling mode. An electromagnetic valve 30 for reheating that is closed by means of is interposed. In this case, the refrigerant pipe 13G is branched to the bypass pipe 35 on the upstream side of the solenoid valve 30, and the bypass pipe 35 is opened in the dehumidifying heating mode and the MAX cooling mode, and the heating mode, the dehumidifying cooling mode, the cooling mode, Further, it is communicatively connected to the refrigerant pipe 13E on the downstream side of the outdoor expansion valve 6 via a bypass solenoid valve 40 that is closed in the defrosting mode. The bypass pipe 45, the solenoid valve 30, and the solenoid valve 40 constitute a bypass device 45.

  By configuring the bypass device 45 with the bypass pipe 35, the solenoid valve 30, and the solenoid valve 40, the dehumidifying and heating mode in which the refrigerant discharged from the compressor 2 directly flows into the outdoor heat exchanger 7 and the MAX mode. The cooling mode and the heating mode for allowing the refrigerant discharged from the compressor 2 to flow into the radiator 4, the dehumidifying and cooling mode, the cooling mode, and the defrosting mode can be smoothly switched.

  Further, in the air flow passage 3 on the air upstream side of the heat absorber 9, respective intake ports of an outside air intake port and an inside air intake port are formed (represented by the intake port 25 in FIG. 1). 25 is provided with a suction switching damper 26 for switching the air introduced into the air flow passage 3 between the inside air (inside air circulation mode) which is the air inside the vehicle interior and the outside air (outside air introduction mode) which is the air outside the vehicle interior. There is. Further, on the air downstream side of the suction switching damper 26, an indoor blower (blower fan) 27 for feeding the introduced inside air or outside air to the air flow passage 3 is provided.

  Reference numeral 23 in FIG. 1 denotes an auxiliary heater as an auxiliary heating device provided in the vehicle air conditioner 1 of the embodiment. The auxiliary heater 23 of the embodiment is composed of a PTC heater which is an electric heater, and is provided in the air flow passage 3 on the upstream side of the radiator 4 with respect to the air flow in the air flow passage 3. There is. When the auxiliary heater 23 is energized to generate heat, the air in the air flow passage 3 flowing into the radiator 4 via the heat absorber 9 is heated. That is, the auxiliary heater 23 functions as a so-called heater core to heat the interior of the vehicle or complement it.

  In addition, the air (inside air or outside air) in the air flow passage 3 that has flowed into the air flow passage 3 and passed through the heat absorber 9 is assisted in the air flow passage 3 on the air upstream side of the auxiliary heater 23. An air mix damper 28 that adjusts the ratio of ventilation to the heater 23 and the radiator 4 is provided. Further, FOOT (foot), VENT (vent), and DEF (def) outlets (represented by the outlet 29 in FIG. 1 as a representative) are formed in the air passage 3 on the air downstream side of the radiator 4. The blowout port 29 is provided with a blowout port switching damper 31 for controlling the switching of the blowout of air from the blowout ports.

Next, in FIG. 2, reference numeral 32 denotes a controller (ECU) as a control device that is configured by a microcomputer that is an example of a computer including a processor, and the outside temperature (Tam) of the vehicle is detected at the input of the controller 32. The outside air temperature sensor 33, the outside air humidity sensor 34 that detects the outside air humidity, the HVAC suction temperature sensor 36 that detects the temperature of the air sucked into the air flow passage 3 from the suction port 25, and the air inside the vehicle (inside air). An inside air temperature sensor 37 for detecting the temperature, an inside air humidity sensor 38 for detecting the humidity of the air in the vehicle interior, an indoor CO ₂ concentration sensor 39 for detecting the carbon dioxide concentration in the vehicle interior, and a blowout port 29 into the vehicle interior. And a discharge pressure sensor for detecting the discharge refrigerant pressure (discharge pressure Pd) of the compressor 2. 42, a discharge temperature sensor 43 for detecting the discharge refrigerant temperature of the compressor 2, a suction pressure sensor 44 for detecting the suction refrigerant pressure of the compressor 2, and a suction temperature for detecting the suction refrigerant temperature (Ts) of the compressor 2. The sensor 55, the radiator temperature sensor 46 for detecting the temperature of the radiator 4 (the temperature of the air passing through the radiator 4, or the temperature of the radiator 4 itself: the radiator temperature TH), and the refrigerant pressure of the radiator 4 ( The radiator pressure sensor 47 that detects the pressure of the refrigerant inside the radiator 4 or immediately after exiting the radiator 4, ie, the radiator pressure PCI, and the temperature of the heat absorber 9 (the temperature of the air that has passed through the heat absorber 9, or , Temperature of heat absorber 9 itself: heat absorber temperature sensor 48 for detecting heat absorber temperature Te), and refrigerant pressure of the heat absorber 9 (pressure of the refrigerant inside the heat absorber 9 or immediately after leaving the heat absorber 9) Detects heat absorber pressure sensor 49 and detects the amount of solar radiation into the passenger compartment For example, a photo sensor type solar radiation sensor 51, a vehicle speed sensor 52 for detecting a moving speed (vehicle speed) of the vehicle, an air conditioning (air conditioner) operation unit 53 for setting a set temperature and switching of operation modes, An outdoor heat exchanger temperature sensor 54 for detecting the temperature of the outdoor heat exchanger 7 (the temperature of the refrigerant immediately after exiting the outdoor heat exchanger 7, or the temperature of the outdoor heat exchanger 7 itself: the outdoor heat exchanger temperature TXO). And an outdoor heat exchanger pressure sensor for detecting the refrigerant pressure of the outdoor heat exchanger 7 (the pressure of the refrigerant in the outdoor heat exchanger 7 or immediately after it has exited from the outdoor heat exchanger 7: the outdoor heat exchanger pressure PXO). Each output of 56 is connected. An auxiliary heater temperature sensor for detecting the temperature of the auxiliary heater 23 (the temperature of the air immediately after being heated by the auxiliary heater 23, or the temperature of the auxiliary heater 23 itself: the auxiliary heater temperature Tptc) is also input to the controller 32. The output of 50 is also connected.

  On the other hand, the output of the controller 32 is the compressor 2, the outdoor blower 15, the indoor blower (blower fan) 27, the suction switching damper 26, the air mix damper 28, the outlet switching damper 31, and the outdoor expansion. Valve 6, indoor expansion valve 8 and auxiliary heater 23, solenoid valve 30 (for reheat), solenoid valve 17 (for cooling), solenoid valve 21 (for heating), solenoid valve 40 (for bypass) are connected to each solenoid valve. Has been done. Then, the controller 32 controls these based on the output of each sensor and the setting input by the air conditioning operation unit 53.

  Next, the operation of the vehicle air conditioner 1 of the embodiment having the above configuration will be described. In the embodiment, the controller 32 switches and executes each operation mode of a heating mode, a dehumidifying heating mode, a dehumidifying cooling mode, a cooling mode, a MAX cooling mode (maximum cooling mode), and a defrosting mode. First, an outline of the flow of refrigerant and control in each operation mode will be described.

(1) Heating Mode When the heating mode is selected by the controller 32 (auto mode) or the manual operation (manual mode) to the air conditioning operation unit 53, the controller 32 opens the solenoid valve 21 (for heating) to open the solenoid valve. Close 17 (for cooling). Further, the solenoid valve 30 (for reheat) is opened, and the solenoid valve 40 (for bypass) is closed.

  Then, the compressor 2 and each of the blowers 15 and 27 are operated, and the air mix damper 28 blows out from the indoor blower 27 and passes through the heat absorber 9 in the air flow passage 3 as shown by a broken line in FIG. The air is ventilated by the auxiliary heater 23 and the radiator 4. As a result, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the radiator 4 through the electromagnetic valve 30 and the refrigerant pipe 13G. Since the air in the air flow passage 3 is ventilated through the radiator 4, the air in the air flow passage 3 is heated to a high temperature refrigerant in the radiator 4 (when the auxiliary heater 23 operates, the auxiliary heater 23 and the radiator 4). ), The refrigerant in the radiator 4 is deprived of heat by the air to be cooled and condensed and liquefied.

  The refrigerant liquefied in the radiator 4 exits the radiator 4 and then reaches the outdoor expansion valve 6 via the refrigerant pipe 13E. The refrigerant flowing into the outdoor expansion valve 6 is decompressed there, and then flows into the outdoor heat exchanger 7. The refrigerant that has flowed into the outdoor heat exchanger 7 evaporates, and heat is drawn up while traveling or from the outside air ventilated by the outdoor blower 15. That is, the refrigerant circuit R serves as a heat pump. Then, the low-temperature refrigerant that has exited the outdoor heat exchanger 7 enters the accumulator 12 from the refrigerant pipe 13C via the refrigerant pipe 13A, the electromagnetic valve 21 and the refrigerant pipe 13D, and is separated into gas and liquid there, and then the gas refrigerant is compressed into the compressor 2. The circulation that is sucked in is repeated. The air heated by the radiator 4 (when the auxiliary heater 23 operates, the auxiliary heater 23 and the radiator 4) is blown out from the air outlet 29, so that the interior of the vehicle is heated.

  The controller 32 calculates the target radiator pressure PCO (the target value of the radiator pressure PCI) from the target radiator temperature TCO (the target value of the radiator temperature TH) calculated from the target outlet temperature TAO described later, and this target heat radiation The rotation speed of the compressor 2 is controlled based on the unit pressure PCO and the refrigerant pressure of the radiator 4 (radiator pressure PCI; high pressure of the refrigerant circuit R) detected by the radiator pressure sensor 47. Further, the controller 32 sets the valve opening degree of the outdoor expansion valve 6 based on the temperature of the radiator 4 (radiator temperature TH) detected by the radiator temperature sensor 46 and the radiator pressure PCI detected by the radiator pressure sensor 47. Then, the supercooling degree SC of the refrigerant at the outlet of the radiator 4 (calculated from the radiator temperature TH and the radiator pressure PCI) is controlled to a predetermined target supercooling degree TGSC which is its target value. The target radiator temperature TCO is basically set to TCO = TAO, but a predetermined limit for control is set.

  Further, in this heating mode, when the heating capacity of the radiator 4 is insufficient with respect to the heating capacity required for air conditioning in the vehicle interior, the controller 32 assists the supplementary heat by the heat generated by the auxiliary heater 23. The energization of the heater 23 is controlled. As a result, comfortable vehicle interior heating is realized, and frost formation on the outdoor heat exchanger 7 is also suppressed. At this time, since the auxiliary heater 23 is arranged on the air upstream side of the radiator 4, the air flowing through the air flow passage 3 is ventilated by the auxiliary heater 23 before the radiator 4.

Here, when the auxiliary heater 23 is arranged on the air downstream side of the radiator 4, when the auxiliary heater 23 is configured by the PTC heater as in the embodiment, the temperature of the air flowing into the auxiliary heater 23 is the radiator. 4, the resistance value of the PTC heater increases, the current value also decreases, and the amount of heat generation decreases. However, by arranging the auxiliary heater 23 on the upstream side of the radiator 4 in the air, As described above, the capability of the auxiliary heater 23 including the PTC heater can be fully exerted.

(2) Dehumidification Heating Mode Next, in the dehumidification heating mode, the controller 32 opens the solenoid valve 17 and closes the solenoid valve 21. Further, the solenoid valve 30 is closed, the solenoid valve 40 is opened, and the opening degree of the outdoor expansion valve 6 is fully closed. Then, the compressor 2 and each of the blowers 15 and 27 are operated, and the air mix damper 28 blows out from the indoor blower 27 and passes through the heat absorber 9 in the air flow passage 3 as shown by a broken line in FIG. The air is ventilated by the auxiliary heater 23 and the radiator 4.

  As a result, the high-temperature high-pressure gas refrigerant discharged from the compressor 2 to the refrigerant pipe 13G flows into the bypass pipe 35 without going to the radiator 4, passes through the solenoid valve 40, and is located downstream of the outdoor expansion valve 6 in the refrigerant pipe. It reaches 13E. At this time, since the outdoor expansion valve 6 is fully closed, the refrigerant flows into the outdoor heat exchanger 7. The refrigerant that has flowed into the outdoor heat exchanger 7 is condensed by being cooled there by traveling or by the outside air ventilated by the outdoor blower 15. The refrigerant discharged from the outdoor heat exchanger 7 sequentially flows from the refrigerant pipe 13A through the solenoid valve 17 into the receiver dryer section 14 and the supercooling section 16. Here, the refrigerant is supercooled.

  The refrigerant discharged from the supercooling section 16 of the outdoor heat exchanger 7 enters the refrigerant pipe 13B, passes through the internal heat exchanger 19, and reaches the indoor expansion valve 8. The refrigerant is decompressed by the indoor expansion valve 8, then flows into the heat absorber 9 and evaporates. Due to the heat absorbing action at this time, the air blown out from the indoor blower 27 is cooled, and the moisture in the air is condensed and attached to the heat absorber 9, so that the air in the air flow passage 3 is cooled, and Dehumidified. The refrigerant evaporated in the heat absorber 9 reaches the accumulator 12 via the internal heat exchanger 19 and the refrigerant pipe 13C, and is repeatedly sucked into the compressor 2 through the circulation.

  At this time, since the valve opening degree of the outdoor expansion valve 6 is fully closed, it is possible to suppress or prevent the inconvenience that the refrigerant discharged from the compressor 2 flows back into the radiator 4 from the outdoor expansion valve 6. Becomes This makes it possible to suppress or eliminate the decrease in the refrigerant circulation amount and secure the air conditioning capacity. Further, in the dehumidifying and heating mode, the controller 32 energizes the auxiliary heater 23 to generate heat. As a result, the air cooled by the heat absorber 9 and dehumidified is further heated in the process of passing through the auxiliary heater 23, and the temperature rises, so that dehumidification and heating of the vehicle interior is performed.

  The controller 32 controls the rotation speed of the compressor 2 based on the temperature of the heat absorber 9 (heat absorber temperature Te) detected by the heat absorber temperature sensor 48 and the target heat absorber temperature TEO which is the target value thereof, and also the auxiliary heater temperature. By controlling the energization (heat generation) of the auxiliary heater 23 based on the auxiliary heater temperature Tptc detected by the sensor 50 and the target radiator temperature TCO described above, while appropriately cooling and dehumidifying the air in the heat absorber 9, By the heating by the auxiliary heater 23, the temperature of the air blown into the vehicle compartment from the air outlet 29 is accurately prevented.

  This makes it possible to control the temperature of the air blown into the vehicle compartment to an appropriate heating temperature while dehumidifying the air, and to realize comfortable and efficient dehumidification and heating of the vehicle compartment. Further, as described above, in the dehumidifying and heating mode, the air mix damper 28 is in a state in which all the air in the air flow passage 3 is ventilated to the auxiliary heater 23 and the radiator 4, so that the air that has passed through the heat absorber 9 is efficiently assisted. It becomes possible to improve the energy saving by heating with the heater 23 and also improve the controllability of the dehumidifying heating air conditioning.

  Since the auxiliary heater 23 is arranged on the air upstream side of the radiator 4, the air heated by the auxiliary heater 23 passes through the radiator 4, but in this dehumidifying and heating mode, the refrigerant is fed to the radiator 4. Since the heat is not flowed, the disadvantage that the radiator 4 absorbs heat from the air heated by the auxiliary heater 23 is also eliminated. That is, the radiator 4 is prevented from lowering the temperature of the air blown into the vehicle compartment, and the COP is also improved.

(3) Dehumidifying and Cooling Mode Next, in the dehumidifying and cooling mode, the controller 32 opens the electromagnetic valve 17 and closes the electromagnetic valve 21. Further, the solenoid valve 30 is opened and the solenoid valve 40 is closed. Then, the compressor 2 and each of the blowers 15 and 27 are operated, and the air mix damper 28 blows out from the indoor blower 27 and passes through the heat absorber 9 in the air flow passage 3 as shown by a broken line in FIG. The air is ventilated by the auxiliary heater 23 and the radiator 4. As a result, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the radiator 4 through the electromagnetic valve 30 and the refrigerant pipe 13G. Since the air in the air flow passage 3 is ventilated through the radiator 4, the air in the air flow passage 3 is heated by the high temperature refrigerant in the radiator 4, while the refrigerant in the radiator 4 heats the air. It is deprived, cooled, and condensed into a liquid.

  The refrigerant discharged from the radiator 4 reaches the outdoor expansion valve 6 through the refrigerant pipe 13E, and flows into the outdoor heat exchanger 7 through the outdoor expansion valve 6 which is controlled to open. The refrigerant that has flowed into the outdoor heat exchanger 7 is condensed by being cooled there by traveling or by the outside air ventilated by the outdoor blower 15. The refrigerant discharged from the outdoor heat exchanger 7 sequentially flows from the refrigerant pipe 13A through the solenoid valve 17 into the receiver dryer section 14 and the supercooling section 16. Here, the refrigerant is supercooled.

  The refrigerant discharged from the supercooling section 16 of the outdoor heat exchanger 7 enters the refrigerant pipe 13B, passes through the internal heat exchanger 19, and reaches the indoor expansion valve 8. The refrigerant is decompressed by the indoor expansion valve 8, then flows into the heat absorber 9 and evaporates. Due to the heat absorbing action at this time, the water in the air blown out from the indoor blower 27 is condensed and adheres to the heat absorber 9, so that the air is cooled and dehumidified.

  The refrigerant evaporated in the heat absorber 9 reaches the accumulator 12 via the internal heat exchanger 19 and the refrigerant pipe 13C, and is repeatedly sucked into the compressor 2 through the circulation. In this dehumidifying and cooling mode, the controller 32 does not energize the auxiliary heater 23, so that the air cooled by the heat absorber 9 and dehumidified is reheated in the process of passing through the radiator 4 (reheat. The heat radiation capacity is lower than that during heating. ) Will be done. As a result, the dehumidifying and cooling of the vehicle interior is performed.

  The controller 32 controls the rotation speed of the compressor 2 based on the temperature of the heat absorber 9 (heat absorber temperature Te) detected by the heat absorber temperature sensor 48, and also the outdoor expansion valve based on the high pressure of the refrigerant circuit R described above. The valve pressure of the radiator 6 is controlled to control the refrigerant pressure of the radiator 4 (radiator pressure PCI).

(4) Cooling Mode Next, in the cooling mode, the controller 32 fully opens the valve opening degree of the outdoor expansion valve 6 in the dehumidifying and cooling mode state. The controller 32 controls the air mix damper 28 so that the air in the air flow passage 3 after being blown out from the indoor blower 27 and passing through the heat absorber 9 causes the auxiliary heater 23 and the heat radiation as shown by the solid line in FIG. Adjust the rate of ventilation to the vessel 4. Further, the controller 32 does not energize the auxiliary heater 23.

  As a result, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the radiator 4 from the refrigerant pipe 13G via the electromagnetic valve 30, and the refrigerant that has left the radiator 4 flows to the outdoor expansion valve 6 via the refrigerant pipe 13E. Leading to. At this time, since the outdoor expansion valve 6 is fully opened, the refrigerant passes through it and flows into the outdoor heat exchanger 7 as it is, where it is air-cooled by traveling or by the outside air ventilated by the outdoor blower 15. Liquefy. The refrigerant discharged from the outdoor heat exchanger 7 sequentially flows from the refrigerant pipe 13A through the solenoid valve 17 into the receiver dryer section 14 and the supercooling section 16. Here, the refrigerant is supercooled.

  The refrigerant discharged from the supercooling section 16 of the outdoor heat exchanger 7 enters the refrigerant pipe 13B, passes through the internal heat exchanger 19, and reaches the indoor expansion valve 8. The refrigerant is decompressed by the indoor expansion valve 8, then flows into the heat absorber 9 and evaporates. The air blown from the indoor blower 27 is cooled by the heat absorbing action at this time. Further, the water in the air is condensed and attached to the heat absorber 9.

  The refrigerant evaporated in the heat absorber 9 reaches the accumulator 12 via the internal heat exchanger 19 and the refrigerant pipe 13C, and is repeatedly sucked into the compressor 2 through the circulation. Since the air cooled and dehumidified by the heat absorber 9 is blown into the vehicle interior from the air outlet 29 (a part of the air passes through the radiator 4 to exchange heat), the interior of the vehicle is cooled. become. Further, in this cooling mode, the controller 32 determines the rotation speed of the compressor 2 based on the temperature of the heat absorber 9 (heat absorber temperature Te) detected by the heat absorber temperature sensor 48 and the target heat absorber temperature TEO which is its target value. To control.

(5) MAX cooling mode (maximum cooling mode)
Next, in the MAX cooling mode as the maximum cooling mode, the controller 32 opens the solenoid valve 17 and closes the solenoid valve 21. Further, the solenoid valve 30 is closed, the solenoid valve 40 is opened, and the opening degree of the outdoor expansion valve 6 is fully closed. Then, the compressor 2 and the blowers 15 and 27 are operated, and the air mix damper 28 makes the air in the air flow passage 3 not ventilated to the auxiliary heater 23 and the radiator 4 as shown in FIG. However, there is no problem even if there is some ventilation. Further, the controller 32 does not energize the auxiliary heater 23.

  As a result, the high-temperature high-pressure gas refrigerant discharged from the compressor 2 to the refrigerant pipe 13G flows into the bypass pipe 35 without going to the radiator 4, passes through the solenoid valve 40, and is located downstream of the outdoor expansion valve 6 in the refrigerant pipe. It reaches 13E. At this time, since the outdoor expansion valve 6 is fully closed, the refrigerant flows into the outdoor heat exchanger 7. The refrigerant that has flowed into the outdoor heat exchanger 7 is condensed by being cooled there by traveling or by the outside air ventilated by the outdoor blower 15. The refrigerant discharged from the outdoor heat exchanger 7 sequentially flows from the refrigerant pipe 13A through the solenoid valve 17 into the receiver dryer section 14 and the supercooling section 16. Here, the refrigerant is supercooled.

  The refrigerant discharged from the supercooling section 16 of the outdoor heat exchanger 7 enters the refrigerant pipe 13B, passes through the internal heat exchanger 19, and reaches the indoor expansion valve 8. The refrigerant is decompressed by the indoor expansion valve 8, then flows into the heat absorber 9 and evaporates. The air blown from the indoor blower 27 is cooled by the heat absorbing action at this time. Further, the water in the air is condensed and attached to the heat absorber 9, so that the air in the air flow passage 3 is dehumidified. The refrigerant evaporated in the heat absorber 9 reaches the accumulator 12 via the internal heat exchanger 19 and the refrigerant pipe 13C, and is repeatedly sucked into the compressor 2 through the circulation. At this time, since the outdoor expansion valve 6 is fully closed, it is possible to suppress or prevent the disadvantage that the refrigerant discharged from the compressor 2 flows backward from the outdoor expansion valve 6 into the radiator 4 in the same manner. .. This makes it possible to suppress or eliminate the decrease in the refrigerant circulation amount and secure the air conditioning capacity.

  Here, in the cooling mode described above, since a high-temperature refrigerant is flowing through the radiator 4, direct heat conduction from the radiator 4 to the HVAC unit 10 is not a little generated, but in the MAX cooling mode, the refrigerant is radiated to the radiator 4. Does not flow, the heat transferred from the radiator 4 to the HVAC unit 10 does not heat the air in the air flow passage 3 from the heat absorber 9. Therefore, strong cooling of the vehicle interior is performed, and particularly in an environment where the outside air temperature Tam is high, it is possible to quickly cool the vehicle interior and realize comfortable vehicle air conditioning. Also in this MAX cooling mode, the controller 32 rotates the compressor 2 based on the temperature of the heat absorber 9 (heat absorber temperature Te) detected by the heat absorber temperature sensor 48 and the target heat absorber temperature TEO which is its target value. Control the number.

(6) Switching between operation modes of heating, dehumidifying heating, dehumidifying cooling, cooling, and MAX cooling The air flowing in the air flow passage 3 is cooled from the heat absorber 9 and the radiator 4 (and auxiliary) in each of the above operation modes. It is heated by the heater 23) (adjusted by the air mix damper 28) and blown out into the vehicle compartment from the air outlet 29. The controller 32 is set in the air-conditioning operation section 53, such as the outside air temperature Tam detected by the outside air temperature sensor 33, the temperature inside the vehicle detected by the inside air temperature sensor 37, the blower voltage, the amount of solar radiation detected by the solar radiation sensor 51, and the like. The target outlet temperature TAO is calculated based on the target passenger compartment temperature (set temperature) in the passenger compartment, and the operating modes are switched to control the temperature of the air blown from the outlet 29 to this target outlet temperature TAO.

  In this case, the controller 32 controls the outside air temperature Tam, the humidity in the vehicle compartment, the target outlet temperature TAO, the radiator temperature TH, the target radiator temperature TCO, the heat absorber temperature Te, the target heat absorber temperature TEO, and the presence or absence of the dehumidification request in the vehicle compartment. By switching each operation mode based on parameters such as, etc., the heating mode, the dehumidification heating mode, the dehumidification cooling mode, the cooling mode and the MAX cooling mode can be switched appropriately according to the environmental conditions and the necessity of dehumidification. Achieves efficient vehicle interior air conditioning.

(7) Defrost Mode In the defrost mode for removing the frost adhering to the outdoor heat exchanger 7, the controller 32 detects the growth of frost on the outdoor heat exchanger 7 from the operating state. Run. In that case, the controller 32 opens the solenoid valve 21 and closes the solenoid valve 17. Further, the solenoid valve 30 is opened and the solenoid valve 40 is closed. Further, the outdoor expansion valve 6 is fully opened.

  Then, the compressor 2 is operated. However, the blowers 15 and 27 are stopped. As a result, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows from the refrigerant pipe 13G into the radiator 4 via the electromagnetic valve 30, reaches the outdoor expansion valve 6 via the electromagnetic valve 30, and passes through there to reach the outdoor heat exchange. Flows into the vessel 7. The refrigerant flowing into the outdoor heat exchanger 7 radiates heat there, heats the outdoor heat exchanger 7 to melt the frost adhering to the outdoor heat exchanger 7, and lowers itself in temperature or condenses entirely or partially. Then, the refrigerant discharged from the outdoor heat exchanger 7 enters the accumulator 12 from the refrigerant pipe 13C through the refrigerant pipe 13A, the solenoid valve 21 and the refrigerant pipe 13D, and is separated into gas and liquid therein, and then the gas refrigerant is sucked into the compressor 2. Repeat the cycle that is repeated. As a result, the outdoor heat exchanger 7 is defrosted. The controller 32 detects the end of defrosting of the outdoor heat exchanger 7 from the temperature (outdoor heat exchanger temperature) TXO of the outdoor heat exchanger 7, and ends the defrosting mode.

(8) Failure Confirmation Mode by Controller 32 Next, the failure confirmation mode and the failure valve confirmation mode executed by the controller 32 will be described with reference to FIG. FIG. 4 shows an abnormality (abnormal state) in the operating state of the refrigerant circuit R that is considered (estimated) due to a failure of the solenoid valve 17, the solenoid valve 21, the solenoid valve 30, the solenoid valve 40, and the outdoor expansion valve 6. There is.

(8-1) Failure Confirmation Mode in Heating Mode First, the failure confirmation mode in the heating mode will be described.
(8-1-1) Closing Fault of Solenoid Valve 30 When a closing fault occurs in which the solenoid valve 30 (reheat) does not open in the heating mode, the solenoid valve 40 (bypass) is also closed. Since there is no place for the discharged refrigerant to go, the discharge pressure Pd of the compressor 2 rises and finally reaches a predetermined protection stop value. Therefore, when the discharge pressure Pd detected by the discharge pressure sensor 42 rises to a predetermined protection stop value in the heating mode, the controller 32 estimates that the closing failure of the solenoid valve 30 is the cause and shifts to the failure confirmation mode.

  In this failure confirmation mode, the controller 32 sets the rotation speed NC of the compressor 2 to a constant value. Then, the discharge pressure Pd detected by the discharge pressure sensor 42 at the rotational speed in the normal state is measured in advance as a normal detection value, and the normal detection value and the discharge pressure Pd currently detected by the discharge pressure sensor 42 (detection) are detected. Value), and if the difference between them is larger than a predetermined value, it is determined that the solenoid valve 30 has a closed failure (the discharge pressure Pd is the protection stop value, so the difference naturally increases). Then, the controller 32 displays the failure occurrence in the air conditioning operation unit 53 and notifies the user (notification operation).

(8-1-2) Open Failure of Solenoid Valve 40 When an open failure occurs in which the solenoid valve 40 (bypass) does not close in the heating mode, the refrigerant flowing to the radiator 4 decreases, so that the refrigerant circuit R COP is low. Therefore, when the COP drops below the predetermined value in the heating mode, the controller 32 estimates that the open failure of the solenoid valve 40 is the cause, and shifts to the failure confirmation mode.

  Even in this failure confirmation mode, the controller 32 sets the rotation speed NC of the compressor 2 to a constant value. Then, the COP calculated at the rotational speed in the normal state is measured in advance as a normal calculated value, and this normal calculated value is compared with the currently calculated COP (calculated value), and the difference between them is a predetermined value. When it becomes larger, it is determined that the solenoid valve 40 has an open failure. Also in this case, the controller 32 also displays the failure occurrence in the air conditioning operation unit 53 and notifies the user (notification operation).

(8-1-3) Closing Failure of Solenoid Valve 21 When a closing failure occurs in which the solenoid valve 21 (heating) does not open in the heating mode, the solenoid valve 17 (cooling) is also closed. Since there is no place for the refrigerant to go out of the vessel 7, the outdoor heat exchanger temperature TXO cannot fall. Further, the suction refrigerant temperature Ts of the compressor 2 also does not decrease and becomes equal to the outside air temperature Tam. Therefore, when the outdoor heat exchanger temperature TXO detected by the outdoor heat exchanger temperature sensor 54 is high (not lowered) in the heating mode, or the suction refrigerant temperature Ts detected by the suction temperature sensor 55 is the outside air temperature sensor 33 in the heating mode. When it is equal to the outside air temperature Tam detected by, the cause is presumed to be due to the closing failure of the solenoid valve 21, and the failure determination mode is entered.

  Even in this failure confirmation mode, the controller 32 sets the rotation speed NC of the compressor 2 to a constant value. The outdoor heat exchanger temperature TXO detected by the outdoor heat exchanger temperature sensor 54 in the normal state is measured in advance as a normal detection value, and the normal detection value and the current outdoor heat exchanger temperature sensor 54 are The detected outdoor heat exchanger temperature TXO (detection value) is compared, and if the difference between them is larger than a predetermined value, it is determined that the solenoid valve 21 is closed. Further, the suction refrigerant temperature Ts detected by the suction temperature sensor 55 in the normal state is measured in advance as a normal detection value, and the normal detection value and the suction refrigerant temperature Ts currently detected by the suction temperature sensor 55 are measured. (Detected value) is compared, and when the difference between them is larger than a predetermined value and the detected value is equal to the outside air temperature Tam, it is determined that the solenoid valve 21 is closed. Then, the controller 32 displays the failure occurrence in the air conditioning operation unit 53 and notifies the user (notification operation).

(8-1-4) Closed Failure of Outdoor Expansion Valve 6 When a closed failure occurs in which the outdoor expansion valve 6 does not open in the heating mode, the refrigerant stays in the radiator 4, so that the refrigerant in the radiator 4 is blocked. The supercooling degree SC becomes abnormally large. Moreover, the temperature (TH) of the radiator 4 does not change after the compressor 2 is started. Therefore, the controller 32 operates when the degree of supercooling SC of the refrigerant in the radiator 4 calculated in the heating mode is abnormally large, or when the radiator temperature TH detected by the radiator temperature sensor 46 starts from the start of the compressor 2. If it does not change, it is estimated that the closing failure of the outdoor expansion valve 6 is the cause, and the failure determination mode is entered.

  Even in this failure confirmation mode, the controller 32 sets the rotation speed NC of the compressor 2 to a constant value. Then, the subcooling degree SC of the refrigerant in the radiator 4 calculated at the number of rotations in the normal state is calculated in advance as a normal calculation value, and the normal calculation value and the currently calculated supercooling degree SC (calculation value) are calculated. ) And the calculated value is larger than the normal calculated value and the difference between them is larger than a predetermined value, it is determined that the outdoor expansion valve 6 is closed. Further, the radiator temperature TH detected by the radiator temperature sensor 46 in the normal state is measured in advance as a normal detection value, and the normal detection value and the radiator currently detected by the radiator temperature sensor 46 are measured. The temperature TH (detection value) is compared, and even if the difference between them is larger than a predetermined value, it is determined that the outdoor expansion valve 6 is closed. Then, the controller 32 displays the failure occurrence in the air conditioning operation unit 53 and notifies the user (notification operation).

(8-1-5) Opening failure of the outdoor expansion valve 6 When the opening failure occurs in which the outdoor expansion valve 6 does not close in the heating mode, the refrigerant after exiting the radiator 4 cannot be throttled. The temperature TH does not rise and the supercooling degree SC of the refrigerant does not reach the target supercooling degree TGSC (not reached). Therefore, when the supercooling degree SC of the refrigerant in the radiator 4 calculated in the heating mode does not reach the target supercooling degree TGSC, the controller 32 estimates that the open failure of the outdoor expansion valve 6 is the cause, and the failure confirmation mode is set. Transition.

  Even in this failure confirmation mode, the controller 32 sets the rotation speed NC of the compressor 2 to a constant value. Then, the subcooling degree SC of the refrigerant in the radiator 4 calculated at the number of rotations in the normal state is calculated in advance as a normal calculation value, and the normal calculation value and the currently calculated supercooling degree SC (calculation value) are calculated. ) And the calculated value is smaller than the normal calculated value and the difference between them is larger than a predetermined value, it is determined that the outdoor expansion valve 6 has an open failure. Then, the controller 32 displays the failure occurrence in the air conditioning operation unit 53 and notifies the user (notification operation). As described above, it becomes possible to accurately determine and confirm the failure of each solenoid valve 30, 40, 21 and the outdoor expansion valve 6 in the heating mode, and to warn the user of the failure occurrence of each valve. You will be able to encourage prompt action.

(8-2) Failure Confirmation Mode in Defrost Mode Next, the failure confirmation mode in the defrost mode will be described.
(8-2-1) Closing Failure of Solenoid Valve 30 When the closing failure of the solenoid valve 30 (reheat) occurs in the defrosting mode, the solenoid valve 40 (bypass) is also closed, and therefore the compressor 2 discharges it. Since there is no place for the discharged refrigerant to go, the discharge pressure Pd of the compressor 2 rises and finally reaches a predetermined protection stop value. Therefore, when the discharge pressure Pd detected by the discharge pressure sensor 42 rises to a predetermined protection stop value in the defrosting mode, the controller 32 estimates that the closing failure of the solenoid valve 30 is the cause and shifts to the failure confirmation mode.

  Even in this failure confirmation mode, the controller 32 sets the rotation speed NC of the compressor 2 to a constant value. Then, the discharge pressure Pd detected by the discharge pressure sensor 42 at the rotational speed in the normal state is measured in advance as a normal detection value, and the normal detection value and the discharge pressure Pd currently detected by the discharge pressure sensor 42 (detection) are detected. Value), and if the difference between them is larger than a predetermined value, it is determined that the solenoid valve 30 has a closed failure (the discharge pressure Pd is the protection stop value, so the difference naturally increases). Then, the controller 32 displays the failure occurrence in the air conditioning operation unit 53 and notifies the user (notification operation).

(8-2-2) Closing Failure of Solenoid Valve 21 When the closing failure of the solenoid valve 21 (heating) occurs in the defrosting mode, the solenoid valve 17 (cooling) is also closed, so the outdoor heat exchanger is closed. Since there is no place for the refrigerant to exit from 7, the outdoor heat exchanger temperature TXO cannot fall. Further, the suction refrigerant temperature Ts of the compressor 2 also does not decrease and becomes equal to the outside air temperature Tam. Therefore, when the outdoor heat exchanger temperature TXO detected by the outdoor heat exchanger temperature sensor 54 is high (undecreased) in the defrosting mode, or when the suction refrigerant temperature Ts detected by the suction temperature sensor 55 is the outside air temperature sensor. When it is equal to the outside air temperature Tam detected by 33, it is presumed that the solenoid valve 21 has a closed failure, and the failure determination mode is entered.

  Even in this failure confirmation mode, the controller 32 sets the rotation speed NC of the compressor 2 to a constant value. The outdoor heat exchanger temperature TXO detected by the outdoor heat exchanger temperature sensor 54 in the normal state is measured in advance as a normal detection value, and the normal detection value and the current outdoor heat exchanger temperature sensor 54 are The detected outdoor heat exchanger temperature TXO (detection value) is compared, and if the difference between them is larger than a predetermined value, it is determined that the solenoid valve 21 is closed. Further, the suction refrigerant temperature Ts detected by the suction temperature sensor 55 in the normal state is measured in advance as a normal detection value, and the normal detection value and the suction refrigerant temperature Ts currently detected by the suction temperature sensor 55 are measured. (Detected value) is compared, and when the difference between them is larger than a predetermined value and the detected value is equal to the outside air temperature Tam, it is determined that the solenoid valve 21 is closed. Then, the controller 32 displays the failure occurrence in the air conditioning operation unit 53 and notifies the user (notification operation).

(8-2-3) Close Failure of Outdoor Expansion Valve 6 When the close failure of the outdoor expansion valve 6 occurs in the defrosting mode, the refrigerant stays in the radiator 4, so that the refrigerant in the radiator 4 is overheated. The degree of cooling SC comes to be attached (not originally attached). Therefore, when the supercooling degree SC of the refrigerant in the radiator 4 calculated in the defrosting mode is attached, the controller 32 estimates that the closing failure of the outdoor expansion valve 6 is the cause, and shifts to the failure confirmation mode.

  Even in this failure confirmation mode, the controller 32 sets the rotation speed NC of the compressor 2 to a constant value. Then, the supercooling degree SC of the refrigerant in the radiator 4 calculated at the number of rotations in the normal state is calculated in advance as a normal calculated value (not attached), and the normal calculated value and the currently calculated supercooling degree are calculated. SC (calculated value) is compared, and when the calculated value is larger than the normal calculated value (when SC is attached), it is determined that the outdoor expansion valve 6 is closed. Then, the controller 32 displays the failure occurrence in the air conditioning operation unit 53 and notifies the user (notification operation). As described above, it becomes possible to accurately determine and confirm the failure of each electromagnetic valve 30, 21 and the outdoor expansion valve 6 in the defrosting mode.

(8-3) Failure Confirmation Mode in Dehumidification Heating Mode Next, the failure confirmation mode in the dehumidification heating mode will be described. When the electromagnetic valve 40 (bypass) has a closing failure in the dehumidifying heating mode, since the electromagnetic valve 30 (reheat) is also closed, there is no place for the refrigerant discharged from the compressor 2, so that the compressor 2 The discharge pressure Pd rises and finally reaches a predetermined protection stop value. Therefore, when the discharge pressure Pd detected by the discharge pressure sensor 42 rises to a predetermined protection stop value in the dehumidifying and heating mode, the controller 32 estimates that the closing failure of the solenoid valve 40 is the cause and shifts to the failure confirmation mode.

  Even in this failure confirmation mode, the controller 32 sets the rotation speed NC of the compressor 2 to a constant value. Then, the discharge pressure Pd detected by the discharge pressure sensor 42 at the rotational speed in the normal state is measured in advance as a normal detection value, and the normal detection value and the discharge pressure Pd currently detected by the discharge pressure sensor 42 (detection) are detected. Value), and if the difference between them is larger than a predetermined value, it is determined that the solenoid valve 40 has a closed failure (the discharge pressure Pd is the protection stop value, so the difference naturally increases). Then, the controller 32 displays the failure occurrence in the air conditioning operation unit 53 and notifies the user (notification operation). This makes it possible to accurately determine and determine the failure of the solenoid valve 40 in the dehumidifying and heating mode.

(8-4) Failure Determining Mode in Dehumidifying Cooling Mode / Cooling Mode Next, the failure determining mode in the dehumidifying cooling mode and the cooling mode will be described.
(8-4-1) Close Failure of Solenoid Valve 30 When a close failure occurs in the solenoid valve 30 (reheat) in the dehumidifying cooling mode and the cooling mode, the solenoid valve 40 (bypass) is also closed, so that the compressor is closed. Since there is no place for the refrigerant discharged from No. 2, the discharge pressure Pd of the compressor 2 rises and finally reaches a predetermined protection stop value. Therefore, when the discharge pressure Pd detected by the discharge pressure sensor 42 rises to a predetermined protection stop value in the dehumidifying cooling mode and the cooling mode, the controller 32 estimates that the closing failure of the solenoid valve 30 is the cause, and shifts to the failure confirmation mode. To do.

  Even in this failure confirmation mode, the controller 32 sets the rotation speed NC of the compressor 2 to a constant value. Then, the discharge pressure Pd detected by the discharge pressure sensor 42 at the rotational speed in the normal state is measured in advance as a normal detection value, and the normal detection value and the discharge pressure Pd currently detected by the discharge pressure sensor 42 (detection) are detected. Value), and if the difference between them is larger than a predetermined value, it is determined that the solenoid valve 30 has a closed failure (the discharge pressure Pd is the protection stop value, so the difference naturally increases). Then, the controller 32 displays the failure occurrence in the air conditioning operation unit 53 and notifies the user (notification operation).

(8-4-2) Close Failure of Outdoor Expansion Valve 6 When a close failure of the outdoor expansion valve 6 occurs in the dehumidifying cooling mode and the cooling mode, only the radiator pressure PCI increases and the radiator temperature TH does not rise. Therefore, the supercooling degree SC of the refrigerant is added to the radiator 4. Therefore, when the degree of supercooling SC of the refrigerant in the radiator 4 calculated in the dehumidifying cooling mode and the cooling mode is attached, the controller 32 estimates that the closing failure of the outdoor expansion valve 6 is the cause, and shifts to the failure confirmation mode.

  Even in this failure confirmation mode, the controller 32 sets the rotation speed NC of the compressor 2 to a constant value. Then, the subcooling degree SC of the refrigerant in the radiator 4 calculated at the number of rotations in the normal state is calculated in advance as a normal calculation value, and the normal calculation value and the currently calculated supercooling degree SC (calculation value) are calculated. ) And the calculated value becomes larger than the normal calculated value (when SC is attached), it is determined that the outdoor expansion valve 6 is closed. Then, the controller 32 displays the failure occurrence in the air conditioning operation unit 53 and notifies the user (notification operation).

(8-4-2) Opening Failure of Outdoor Expansion Valve 6 Also, when an opening failure of the outdoor expansion valve 6 occurs in the dehumidifying cooling mode and the cooling mode, the refrigerant after exiting the radiator 4 cannot be throttled, The radiator temperature TH does not reach the target radiator temperature TCO (not reached). Therefore, when the radiator temperature TH detected by the radiator temperature sensor 48 does not reach the target radiator temperature TCO in the dehumidifying cooling mode and the cooling mode, the controller 32 estimates that the open failure of the outdoor expansion valve 6 is the cause, and determines the failure. Switch to mode.

  Even in this failure confirmation mode, the controller 32 sets the rotation speed NC of the compressor 2 to a constant value. Then, the radiator temperature TH detected at the rotation speed in the normal state is calculated in advance as a normal calculation value, and the normal calculation value is compared with the currently detected radiator temperature TH (detection value) to detect the temperature. When the value is lower than the normal detection value and the difference between them is larger than the predetermined value, it is determined that the outdoor expansion valve 6 has an open failure. Then, the controller 32 displays the failure occurrence in the air conditioning operation unit 53 and notifies the user (notification operation). As described above, the failure of the electromagnetic valve 30 and the outdoor expansion valve 6 in the dehumidifying cooling mode and the cooling mode can be accurately determined and confirmed, and the user can be alerted to the occurrence of the failure of each valve and quickly. You can be encouraged to take appropriate measures.

(8-5) Failure Confirmation Mode in MAX Cooling Mode Next, the failure confirmation mode in the MAX cooling mode will be described. When a closing failure occurs in the solenoid valve 40 (bypass) in the MAX cooling mode, since the solenoid valve 30 (reheat) is also closed, there is no place for the refrigerant discharged from the compressor 2, so that the compressor 2 The discharge pressure Pd rises and finally reaches a predetermined protection stop value. Therefore, when the discharge pressure Pd detected by the discharge pressure sensor 42 rises to a predetermined protection stop value in the MAX cooling mode, the controller 32 estimates that the closing failure of the solenoid valve 40 is the cause and shifts to the failure confirmation mode.

  Even in this failure confirmation mode, the controller 32 sets the rotation speed NC of the compressor 2 to a constant value. Then, the discharge pressure Pd detected by the discharge pressure sensor 42 at the rotational speed in the normal state is measured in advance as a normal detection value, and the normal detection value and the discharge pressure Pd currently detected by the discharge pressure sensor 42 (detection) are detected. Value), and if the difference between them is larger than a predetermined value, it is determined that the solenoid valve 40 has a closed failure (the discharge pressure Pd is the protection stop value, so the difference naturally increases). Then, the controller 32 displays the failure occurrence in the air conditioning operation unit 53 and notifies the user (notification operation). As a result, it becomes possible to accurately determine and determine the failure of the electromagnetic valve 40 in the MAX cooling mode.

(9) Fault Valve Confirmation Mode by Controller 32 Next, the fault valve confirmation mode executed by the controller 32 will be described.
(9-1) Failure valve determination mode when the heat absorber temperature Te does not decrease in the MAX cooling mode, the cooling mode, and the dehumidifying cooling mode. Here, the heat absorber temperature Te does not decrease in the MAX cooling mode, the cooling mode, or the dehumidifying cooling mode. The abnormal state of, occurs not only when the solenoid valve 17 (cooling) has a closing failure as shown in FIG. 4, but also when the solenoid valve 21 (heating) has an opening failure. Therefore, it is not possible to know which of the solenoid valve 17 and the solenoid valve 21 is out of order only from the abnormality that the heat absorber temperature Te does not decrease.

  Therefore, in the MAX cooling mode, the cooling mode or the dehumidifying cooling mode, when the heat absorber temperature Te detected by the heat absorber temperature sensor 48 does not decrease (heat absorber does not cool), the controller 32 executes the failure valve confirmation mode. In this failure valve confirmation mode, the controller 32 closes the solenoid valve 21 and the solenoid valve 40, opens the solenoid valve 30, reduces the valve opening degree of the outdoor expansion valve 6, and determines whether the outdoor heat exchanger temperature TXO falls in that state. Determine whether or not.

  When the electromagnetic valve 21 (heating) has an open failure, it cannot be closed, and the refrigerant that has exited the outdoor heat exchanger 7 goes to the accumulator 12. On the other hand, since the outdoor expansion valve 6 is throttled, the outdoor heat exchanger temperature TXO is lowered. Therefore, the controller 32 determines in this failure valve confirmation mode that the outdoor heat exchanger temperature TXO decreases and that the solenoid valve 21 has an open failure, and if the outdoor heat exchanger temperature TXO does not decrease, it determines that the solenoid valve 17 has a closed failure. As a result, even in the case of an abnormal state that the heat absorber temperature Te does not decrease, which may occur due to a failure of either the solenoid valve 21 or the solenoid valve 17 in the MAX cooling mode, the cooling mode, or the dehumidifying cooling mode. , It becomes possible to determine which solenoid valve has failed.

(9-2) Fault valve determination mode when the discharge pressure Pd is equal to the radiator pressure PCI in the MAX cooling mode Also, there is an abnormal state that the discharge pressure Pd of the compressor 2 is equal to the radiator pressure PCI. As shown in FIG. 4, it is caused by an open failure of the solenoid valve 30 or an open failure of the outdoor expansion valve 6. Therefore, it is not possible to know which of the solenoid valve 30 and the outdoor expansion valve 6 has a failure only from the abnormality that the discharge pressure Pd is equal to the radiator pressure PCI.

  Therefore, when the discharge pressure Pd of the compressor 2 is equal to the radiator pressure PCI in the MAX cooling mode, the controller 32 executes the failure valve confirmation mode. In the failure valve determination mode in this case, the controller 32 closes the solenoid valve 40 (bypass) and determines in that state whether the discharge pressure Pd of the compressor 2 rises to a predetermined protection stop value.

  When the solenoid valve 40 is closed, since the solenoid valve 30 is also originally closed, there is no place for the refrigerant discharged from the compressor 2, so the discharge pressure Pd should rise to the protection stop value. It does not rise when 30 has an open failure. Therefore, the controller 32 determines that the solenoid valve 30 has an open failure when the discharge pressure Pd does not increase to the protection stop value in this failure valve determination mode, and the open expansion valve 6 has an open failure when the discharge pressure Pd increases. As a result, even in the case of an abnormal state that the discharge pressure Pd of the compressor 2 is equal to the radiator pressure PCI, which may occur due to a failure of the electromagnetic valve 30 or the outdoor expansion valve 6 in the MAX cooling mode. , It will be possible to determine which valve has failed.

(9-3) Fault valve determination mode when the heat absorber temperature Te does not decrease in the dehumidifying heating mode Further, the abnormal state that the heat absorber temperature Te does not decrease (heat absorber does not cool) in the dehumidifying heating mode is shown in FIG. As shown, the solenoid valve 30 (reheat) has an open failure, the solenoid valve 17 (cooling) has a close failure, the solenoid valve 21 (heating) has an open failure, and the outdoor expansion valve 6 has an open failure. To do. Therefore, it is not possible to know which solenoid valve 30, 17, 21 is malfunctioning or the outdoor expansion valve 6 is malfunctioning only from the abnormality that the heat absorber temperature Te does not decrease in the dehumidifying and heating mode.

  Therefore, in the dehumidification heating mode, the controller 32 executes the failure valve confirmation mode when the heat absorber temperature Te does not decrease. In the failure valve confirmation mode in this case, the controller 32 first sets the solenoid valve 40 to the first state in which the solenoid valve 40 is closed, and in this first state, whether or not the discharge pressure Pd of the compressor 2 rises to a predetermined protection stop value. To determine. Since the solenoid valve 30 is originally closed in the dehumidification heating mode, closing the solenoid valve 40 eliminates the place where the refrigerant discharged from the compressor 2 goes, and the discharge pressure Pd rises. Therefore, when the discharge pressure Pd does not rise to the protection stop value in this first state, the controller 32 determines that the solenoid valve 30 has an open failure.

  If the solenoid valve 30 is normal even in the first state, the controller 32 returns to the original operating state and then the second state in which the heat generation of the auxiliary heater 23 is stopped is set. In this state, it is determined whether the discharge pressure Pd of the compressor 2 becomes equal to the radiator pressure PCI. When the heat generation of the auxiliary heater 23 is stopped in the dehumidifying heating mode, the outdoor expansion valve 6 is originally fully closed, so the radiator pressure PCI does not become the discharge pressure Pd. Therefore, in the second state, when the discharge pressure Pd becomes equal to the radiator pressure PCI, the controller 32 determines that the outdoor expansion valve 6 is open.

  If the outdoor expansion valve 6 is normal even in this second state, the controller 32 next closes the electromagnetic valves 21 and 40, opens the electromagnetic valve 30, and reduces the valve opening degree of the outdoor expansion valve 6. The third state is set. When the solenoid valve 21 has an open failure, it cannot be closed and the refrigerant exiting the outdoor heat exchanger 7 is directed to the accumulator 12. On the other hand, since the outdoor expansion valve 6 is throttled, the outdoor heat exchanger temperature TXO is lowered. Therefore, if the outdoor heat exchanger temperature TXO falls in this third state, the controller 32 determines that the solenoid valve 21 has an open failure.

  If the outdoor heat exchanger temperature TXO does not decrease, it is determined that the solenoid valve 17 is closed. As a result, in the dehumidifying and heating mode, whichever valve fails even if an abnormal state occurs that the heat absorber temperature Te does not decrease, which may occur due to a failure of the solenoid valves 30, 17, 21 or the outdoor expansion valve 6. You will be able to determine what you are doing.

  Then, even when the failure is confirmed in the failure valve confirmation mode as described above, the controller 32 displays the occurrence of the failure in the air conditioning operation unit 53 and notifies the user (informing operation). As a result, the user can be alerted to the occurrence of a failure in each valve to prompt prompt action.

  As described in detail above, according to the vehicle air conditioner 1 of the present invention, the controller 32 causes the temperature (radiator temperature TH, heat absorber temperature Te, outdoor heat exchanger temperature TXO) of each part of the refrigerant circuit R, pressure ( Based on the detected values of the discharge pressure Pd and the radiator pressure PCI) or the calculated values (supercooling degree SC and COP) obtained from them, the operating state is determined by the solenoid valves 17, 21, 30, 40 or the outdoor expansion valve 6 In the case of an abnormal state that is presumed to be caused by the failure of, the rotation speed NC of the compressor 2 is set to a constant value, and the normal detection value of the temperature and the pressure measured in advance at the rotation speed NC of the compressor 2 or By comparing the normal calculated value calculated from them with the detected value or calculated value, the failure confirmation mode for confirming the failure of the solenoid valves 17, 21, 30, 40 or the outdoor expansion valve 6 is executed. So the detected value and positive Detection value, or by comparing the calculated value and the normal calculated value, it is possible to perform the confirmation and determination of a failure of the solenoid valve and the outdoor expansion valve relatively easily.

  Further, the controller 32 has a similar abnormal state due to the failure of the different solenoid valves 17, 21, 30 or the outdoor expansion valve 6 (the heat absorber temperature Te does not decrease, the discharge pressure Pd becomes equal to the radiator pressure PCI). When the failure occurs, the failure valve confirmation mode for confirming the malfunctioning solenoid valve 17, 21, 30 or the outdoor expansion valve 6 is executed, so which solenoid valve 17, 21, 30 is malfunctioning, Alternatively, it becomes possible to determine whether the outdoor expansion valve 6 is out of order.

  It should be noted that the switching control of each operation mode shown in the embodiment is not limited to that, and the outside air temperature Tam, the humidity in the vehicle compartment, the target outlet temperature TAO, depending on the capacity of the vehicle air conditioner and the usage environment. Any one of parameters such as radiator temperature TH, target radiator temperature TCO, heat absorber temperature Te, target heat absorber temperature TEO, presence / absence of dehumidification request in the passenger compartment, or a combination thereof, or all of them are adopted. It is good to set appropriate conditions.

  Further, the auxiliary heating device is not limited to the auxiliary heater 23 shown in the embodiment, but may be a heat medium circulation circuit that circulates the heat medium heated by the heater to heat the air in the air flow passage, or an engine heating. A heater core or the like that circulates the generated radiator water may be used. Further, the configuration of the refrigerant circuit R described in the embodiment is not limited to that, and can be modified within the range not departing from the spirit of the present invention.

1 Vehicle Air Conditioner 2 Compressor 3 Air Flow Path 4 Radiator 6 Outdoor Expansion Valve 7 Outdoor Heat Exchanger 8 Indoor Expansion Valve 9 Heat Absorber 17 Solenoid Valve (Cooling)
21 Solenoid valve (heating)
30 Solenoid valve (reheat)
40 Solenoid valve (bypass)
23 Auxiliary heater (auxiliary heating device)
27 Indoor blower (blower fan)
28 Air mix damper 32 Controller (control device)
35 Bypass piping R Refrigerant circuit

Claims (13)

A compressor for compressing the refrigerant,
An air flow passage through which the air supplied to the vehicle compartment circulates,
A radiator for radiating heat of the refrigerant to heat the air supplied from the air flow passage into the vehicle interior,
A heat absorber for cooling the air supplied to the vehicle compartment from the air flow passage by absorbing the heat of the refrigerant,
An outdoor heat exchanger provided outside the vehicle,
An outdoor expansion valve for reducing the pressure of the refrigerant flowing into the outdoor heat exchanger,
Bypass piping for bypassing the radiator and the outdoor expansion valve to allow the refrigerant discharged from the compressor to directly flow into the outdoor heat exchanger,
A plurality of solenoid valves for switching the flow of refrigerant,
With a control device,
By controlling the solenoid valve by the control device, in a vehicle air conditioner for switching and executing a plurality of operation modes,
The control device, based on the detected value of the temperature and / or the pressure of each part, or the calculated value obtained from them, the operating state is abnormal due to a failure of the solenoid valve or the outdoor expansion valve. When the state is reached, the rotation speed of the compressor is set to a constant value, and the temperature and / or pressure normally detected at the rotation speed of the compressor is normally detected, or a normal calculation is calculated from them. By comparing a value with the detected value, or a calculated value, while performing a failure confirmation mode for confirming a failure of the solenoid valve or the outdoor expansion valve ,
When the same abnormal state occurs due to the failure of the different solenoid valve or the outdoor expansion valve, any one of the solenoid valve or the outdoor expansion valve that may cause the abnormal state fails An air conditioner for a vehicle , which has a failure valve confirmation mode for determining whether or not there is any, and executes different failure valve confirmation modes according to the plurality of operation modes . The control device controls the electromagnetic valve or the outdoor expansion valve that may cause the abnormal state for each of the plurality of operation modes in the failure valve confirmation mode, and responds to a change in the detected value in that case. The air conditioner for a vehicle according to claim 1, wherein which of the valves is defective is determined . An auxiliary heating device for heating the air supplied to the vehicle compartment from the air flow passage,
The control device, as the plurality of operation modes,
A heating mode in which the refrigerant discharged from the compressor is caused to radiate by radiating the heat to the radiator, and after depressurizing the radiated refrigerant, the outdoor heat exchanger absorbs heat.
Dehumidification that causes the refrigerant discharged from the compressor to flow through the outdoor heat exchanger through the bypass pipe to radiate heat, and after decompressing the radiated refrigerant, causes the heat absorber to absorb heat and heat the auxiliary heating device. Heating mode,
Refrigerant discharged from the compressor is caused to flow from the radiator to the outdoor heat exchanger so that the radiator and the outdoor heat exchanger radiate heat, and the radiated refrigerant is decompressed and then absorbed by the heat absorber. Dehumidification cooling mode,
A cooling mode in which the refrigerant discharged from the compressor is caused to flow from the radiator to the outdoor heat exchanger to radiate heat in the outdoor heat exchanger, and after decompressing the radiated refrigerant, the heat absorber absorbs heat. ,
Refrigerant discharged from the compressor is caused to radiate by flowing into the outdoor heat exchanger through the bypass pipe, and after decompressing the radiated refrigerant, a maximum cooling mode in which heat is absorbed by the heat absorber,
Having a defrosting mode in which the refrigerant discharged from the compressor is defrosted by flowing the outdoor heat exchanger from the radiator to the outdoor heat exchanger,
The vehicle air conditioner according to claim 1 or 2, wherein each operation mode is switched and executed by controlling the electromagnetic valve. A solenoid valve for heating that causes the refrigerant that has opened from the outdoor heat exchanger to open in the heating mode and flows to the compressor,
The dehumidification heating mode, the dehumidification cooling mode, the cooling mode, and the electromagnetic valve for cooling to flow the refrigerant discharged from the outdoor heat exchanger in the maximum cooling mode to the heat absorber,
The dehumidifying heating mode, and the bypass solenoid valve that opens the refrigerant in the maximum cooling mode and discharges the refrigerant discharged from the compressor to the bypass pipe,
The heating valve, the dehumidifying and cooling mode, the cooling mode, and the reheating solenoid valve that is opened in the defrosting mode and causes the refrigerant discharged from the compressor to flow to the radiator. The vehicle air conditioner according to claim 3.   In the heating mode, the control device closes the solenoid valve for reheat when the discharge pressure of the compressor rises to a predetermined protection stop value, and opens the solenoid valve for bypass when the COP is low. When the temperature of the outdoor heat exchanger is high, or when the suction refrigerant temperature of the compressor is equal to the outside air temperature, the solenoid valve for heating has a closed failure, and the degree of supercooling of the refrigerant in the radiator is abnormal. Is large, or when the temperature of the radiator does not change from the start of the compressor, the outdoor expansion valve has a closed failure, and when the degree of refrigerant subcooling in the radiator does not reach a target value, the outdoor expansion The vehicle air conditioner according to claim 4, wherein the failure confirmation mode is executed by estimating that the valve has an open failure.   In the defrost mode, the control device, when the discharge pressure of the compressor rises to a predetermined protection stop value, a closing failure of the electromagnetic valve for reheating, when the temperature of the outdoor heat exchanger is high, or, When the suction refrigerant temperature of the compressor is equal to the outside air temperature, it is presumed that the solenoid valve for heating has a closing failure, and when the radiator has a supercooling degree of the refrigerant, the outdoor expansion valve has a closing failure. The vehicle air conditioner according to claim 4 or 5, wherein the failure confirmation mode is executed.   In the dehumidifying and heating mode, the control device estimates that the bypass solenoid valve has a closed failure and executes the failure confirmation mode when the discharge pressure of the compressor rises to a predetermined protection stop value. The air conditioner for a vehicle according to any one of claims 4, 5, and 6.   In the dehumidifying cooling mode or the cooling mode, the control device closes the solenoid valve for reheating when the discharge pressure of the compressor rises to a predetermined protection stop value, and the degree of supercooling of the refrigerant in the radiator. The failure confirmation mode is executed by estimating that the outdoor expansion valve is closed when the temperature is on, and that the outdoor expansion valve is open when the temperature of the radiator does not reach a target value. The vehicle air conditioner according to claim 4, claim 5, claim 6, or claim 7.   In the maximum cooling mode, the control device closes the solenoid valve for bypass when the discharge pressure of the compressor rises to a predetermined protection stop value, and the suction refrigerant temperature of the compressor is equal to the outside air temperature. When there is a certain condition, it is estimated that the electromagnetic valve for cooling has a closed failure, and the failure determination mode is executed, among the claims 4, 5, 6, 7 and 8. 5. The vehicle air conditioner according to any one of 1. The controller, in the maximum cooling mode, the cooling mode or the dehumidifying cooling mode, if the temperature of the heat absorber does not decrease, while performing the failure valve confirmation mode,
In the failure valve confirmation mode, the heating solenoid valve and the bypass solenoid valve are closed, the reheat solenoid valve is opened, the valve opening degree of the outdoor expansion valve is reduced, and in that state, the outdoor heat valve is closed. If the temperature of the exchanger decreases, it is determined that the heating solenoid valve has an open failure, and if the temperature does not decrease, it is determined that the cooling solenoid valve has a close failure. The vehicle air conditioner according to any one of claims 7, 8 and 9. The control device, in the maximum cooling mode, when the discharge pressure of the compressor is equal to the pressure of the radiator, while performing the failure valve confirmation mode,
In the fault valve confirmation mode, when the bypass solenoid valve is closed and the discharge pressure of the compressor does not rise to a predetermined protection stop value in that state, an open fault of the reheat solenoid valve occurs, and when it rises. The open failure of the outdoor expansion valve is confirmed, and any one of claim 4, claim 5, claim 6, claim 7, claim 8, claim 9, and claim 10 is characterized. Vehicle air conditioner. In the dehumidification heating mode, the control device executes the failure valve confirmation mode when the temperature of the heat absorber does not decrease,
In the failure valve confirmation mode,
When the bypass solenoid valve is closed in the first state and the discharge pressure of the compressor does not rise to a predetermined protection stop value in the first state, it is determined that the reheat solenoid valve has an open failure. ,
When the discharge pressure of the compressor becomes equal to the pressure of the radiator in the second state where the heat generation of the auxiliary heating device is stopped, the open failure of the outdoor expansion valve is confirmed. ,
The heating solenoid valve and the bypass solenoid valve are closed, the reheat solenoid valve is opened, and the valve opening degree of the outdoor expansion valve is reduced to a third state. In the third state, the outdoor If the temperature of the heat exchanger drops, it is confirmed that the solenoid valve for heating has an open failure,
When the reheat solenoid valve, the outdoor expansion valve and the heating solenoid valve are normal as the first state, the second state and the third state, the cooling solenoid valve The vehicle according to any one of claims 4, 5, 6, 7, 8, 9, 10 and 11, which is determined to be a closed failure. Air conditioner. The vehicle air conditioner according to any one of claims 1 to 12, wherein the control device executes a predetermined notification operation when a failure of the solenoid valve is confirmed.

Images