JP6738156B2 - 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, an internal condenser that is provided on the vehicle interior side to radiate the refrigerant, and an interior condenser provided on the vehicle interior side are provided. An evaporator that absorbs the refrigerant, an external condenser that is provided outside the passenger compartment to radiate or absorb the refrigerant, a first expansion valve that expands the refrigerant that flows into the external condenser, and a refrigerant that flows into the evaporator The second expansion valve for expanding the internal condenser and the first expansion valve, and the refrigerant discharged from the compressor to the internal condenser or bypass the internal condenser and the first expansion valve. And a first valve for switching the flow directly from the pipe to the external condenser. The refrigerant discharged from the compressor is made to flow to the internal condenser by the first valve to radiate the heat, and the radiated refrigerant is discharged by the first expansion valve. A heating mode in which the pressure is reduced and the heat is absorbed in the external condenser, and the refrigerant discharged from the compressor is radiated in the internal condenser by the first valve, and the radiated refrigerant is decompressed by the second expansion valve and then absorbed in the evaporator. The dehumidifying mode to be performed and the refrigerant discharged from the compressor are passed through the internal condenser and the first expansion valve by the first valve to the external condenser to radiate the heat, and the pressure is reduced by the second expansion valve, and then in the evaporator. A device has been developed that switches and executes a cooling mode for absorbing heat (see, for example, Patent Document 1).

JP, 2013-23210, A JP, 2014-88151, A

Here, when the first valve of Patent Document 1 is composed of two opening/closing valves provided in each refrigerant pipe branched from the discharge side of the compressor, when switching between the heating mode or the dehumidifying mode and the cooling mode, One of the on-off valves is opened and the other is closed. However, since the pressure difference before and after these on-off valves is large, there is a problem that relatively large noise is generated by the refrigerant that suddenly flows to the opened on-off valve.

Here, when switching between heating and cooling, it is proposed to reduce the pressure difference between the high pressure side and the low pressure side of the refrigerant circuit and then open the on-off valve to suppress the generation of abnormal noise (for example, Patent Document 1). 2).

The present invention has been made to solve the above-mentioned conventional technical problems, and is a vehicle air conditioner that includes a bypass pipe that bypasses a radiator and an outdoor expansion valve, and an on-off valve that switches a flow path. It is an object of the present invention to eliminate or reduce the noise generated when the on-off valve is opened during the switching between the heating mode and the dehumidifying and heating mode and the decrease in the outlet temperature.

An air conditioner for a vehicle according to a first aspect of the present invention includes a compressor that compresses a refrigerant, an air flow passage through which air to be supplied into the vehicle compartment circulates, and air that radiates the refrigerant and is supplied from the air flow passage into the vehicle interior. A heat radiator for heating the vehicle, a heat absorber for absorbing 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 exiting the radiator. An outdoor expansion valve for reducing the pressure of the refrigerant flowing into the outdoor heat exchanger, a first opening/closing valve provided between the discharge side of the compressor and the inlet side of the radiator, and the upstream side of this first opening/closing valve. Side bypass, bypass pipe for bypassing the radiator and the outdoor expansion valve and flowing the refrigerant discharged from the compressor to the outdoor heat exchanger, a second on-off valve provided in this bypass pipe, and an air An auxiliary heating device for heating the air supplied from the flow passage into the vehicle compartment and a control device are provided, and by this control device, the first on-off valve is opened and the second on-off valve is closed, so that the compressor A heating mode in which the discharged refrigerant is passed through a radiator to dissipate the heat, and the released refrigerant is decompressed by the outdoor expansion valve and then absorbed by the outdoor heat exchanger, and the outdoor expansion valve is fully closed, and the first opening/closing By closing the valve and opening the second opening/closing valve, the refrigerant discharged from the compressor is made to flow to the outdoor heat exchanger through the bypass pipe to radiate the heat, and the radiated refrigerant is decompressed and then absorbed by the heat absorber. At the same time, the dehumidification heating mode for heating the auxiliary heating device is switched and executed, and when the control device switches from the heating mode to the dehumidification heating mode, the control device causes the auxiliary heating device to generate heat so that the temperature of the auxiliary heating device is a predetermined value. When the value becomes equal to or more than the value, the refrigerant discharged from the outdoor heat exchanger is switched to a state in which it flows to the heat absorber, the valve opening degree of the outdoor expansion valve is expanded, and the rotation speed of the compressor is controlled. When the pressure difference before and after the second on-off valve is reduced and the pressure difference becomes equal to or less than a predetermined value, the second on-off valve is opened, the first on-off valve is closed, and the outdoor expansion valve is fully closed. It is characterized by starting the noise improvement control.

An air conditioner for a vehicle according to a second aspect of the present invention includes a compressor that compresses a refrigerant, an air flow passage through which air to be supplied into the vehicle compartment circulates, and air that radiates heat from the refrigerant and is supplied into the vehicle interior from the air flow passage. A heat radiator for heating the vehicle, a heat absorber for absorbing 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 exiting the radiator. An outdoor expansion valve for reducing the pressure of the refrigerant flowing into the outdoor heat exchanger, a first opening/closing valve provided between the discharge side of the compressor and the inlet side of the radiator, and the upstream side of this first opening/closing valve. Side bypass, bypass pipe for bypassing the radiator and the outdoor expansion valve and flowing the refrigerant discharged from the compressor to the outdoor heat exchanger, a second on-off valve provided in this bypass pipe, and an air An auxiliary heating device for heating the air supplied from the flow passage into the vehicle compartment and a control device are provided, and by this control device, the first on-off valve is opened and the second on-off valve is closed, so that the compressor A heating mode in which the discharged refrigerant is passed through a radiator to dissipate the heat, and the released refrigerant is decompressed by the outdoor expansion valve and then absorbed by the outdoor heat exchanger, and the outdoor expansion valve is fully closed, and the first opening/closing By closing the valve and opening the second opening/closing valve, the refrigerant discharged from the compressor is made to flow to the outdoor heat exchanger through the bypass pipe to radiate the heat, and the radiated refrigerant is decompressed and then absorbed by the heat absorber. At the same time, the dehumidifying and heating mode for causing the auxiliary heating device to generate heat is switched and executed.When the control device switches from the heating mode to the dehumidifying and heating mode, the control device causes the auxiliary heating device to generate heat, and the temperature of the auxiliary heating device reaches a predetermined value. In the case of the above, while switching the refrigerant flowing from the outdoor heat exchanger to the heat absorber, the outdoor expansion valve is fully opened, and the rotation speed of the compressor is set to a predetermined low value. The pressure difference before and after the second on-off valve is reduced, and the second on-off valve is opened when the pressure difference becomes equal to or less than a predetermined value or after a predetermined time elapses after the rotation speed of the compressor is set to the low value, It is characterized in that noise improvement control is started by closing the first on-off valve and fully closing the outdoor expansion valve .

An air conditioner for a vehicle according to a third aspect of the present invention includes a compressor that compresses a refrigerant, an air flow passage through which air to be supplied into the vehicle compartment circulates, and air that radiates heat from the refrigerant and is supplied into the vehicle interior from the air flow passage. A heat radiator for heating the vehicle, a heat absorber for absorbing 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 exiting the radiator. An outdoor expansion valve for reducing the pressure of the refrigerant flowing into the outdoor heat exchanger, a first opening/closing valve provided between the discharge side of the compressor and the inlet side of the radiator, and the upstream side of this first opening/closing valve. Side bypass, bypass pipe for bypassing the radiator and the outdoor expansion valve and flowing the refrigerant discharged from the compressor to the outdoor heat exchanger, a second on-off valve provided in this bypass pipe, and an air An auxiliary heating device for heating the air supplied from the flow passage into the vehicle compartment and a control device are provided, and by this control device, the first on-off valve is opened and the second on-off valve is closed, so that the compressor A heating mode in which the discharged refrigerant is passed through a radiator to dissipate the heat, and the released refrigerant is decompressed by the outdoor expansion valve and then absorbed by the outdoor heat exchanger, and the outdoor expansion valve is fully closed, and the first opening/closing By closing the valve and opening the second opening/closing valve, the refrigerant discharged from the compressor is made to flow to the outdoor heat exchanger through the bypass pipe to radiate the heat, and the radiated refrigerant is decompressed and then absorbed by the heat absorber. At the same time, the dehumidifying and heating mode for heating the auxiliary heating device is switched and executed.The heating mode is opened to allow the refrigerant discharged from the outdoor heat exchanger to be sucked into the compressor and closed in the dehumidifying and heating mode. The control device further includes a third on-off valve that allows the refrigerant discharged from the outdoor heat exchanger to flow into the heat absorber, and when the control device switches from the dehumidifying and heating mode to the heating mode, the pressure difference across the first on-off valve is reduced. After the reduction, the first opening/closing valve is opened and the second opening/closing valve is closed, and noise reduction control is executed. In this noise improvement control, the first opening/closing valve is opened and the second opening/closing valve is closed. Therefore, when the pressure difference before and after the third on-off valve becomes equal to or less than the predetermined value, the third on-off valve is opened .

In the vehicle air conditioner according to a fourth aspect of the present invention, in the above invention, the control device opens the outdoor expansion valve and controls the rotation speed of the compressor in the noise improvement control, or stops the compressor. Therefore, the pressure difference before and after the first on-off valve is reduced, and when the pressure difference becomes equal to or less than a predetermined value, the first on-off valve is opened and the second on-off valve is closed.

According to a fifth aspect of the present invention, in the vehicle air conditioner according to the third aspect of the invention, the control device controls the outdoor expansion valve in the heating mode in the noise improvement control and stops the compressor. The pressure difference before and after the opening/closing valve is reduced, and the first opening/closing valve is opened when the pressure difference becomes equal to or less than a predetermined value or after a predetermined time has elapsed after the compressor is stopped, and the second opening/closing valve is opened. Is characterized by closing.

In the vehicle air conditioner of the invention of claim 6, in the invention of claims 3 to 5 , the control device increases the heat generation of the auxiliary heating device in the noise improvement control, and after opening the third opening/closing valve. The heat generation of the auxiliary heating device is reduced.

In the vehicle air conditioner of the invention of claim 7 , in the above invention, the control device reduces the heat generation of the auxiliary heating device when the high pressure side pressure becomes equal to or higher than a predetermined value after opening the third opening/closing valve. The feature is that

According to the invention of claim 1, the compressor for compressing the refrigerant, the air flow passage through which the air supplied to the vehicle compartment circulates, and the heat radiated from the refrigerant to heat the air supplied to the vehicle interior from the air flow passage. Radiator, a heat absorber for absorbing the refrigerant and cooling the air supplied from the air flow passage into the vehicle interior, an outdoor heat exchanger provided outside the vehicle interior, and an outdoor heat exchanger exiting the radiator. An outdoor expansion valve for reducing the pressure of the refrigerant flowing into the first opening/closing valve, a first opening/closing valve provided between the discharge side of the compressor and the inlet side of the radiator, and a branch on the upstream side of the first opening/closing valve. A bypass pipe for bypassing the radiator and the outdoor expansion valve to allow the refrigerant discharged from the compressor to flow to the outdoor heat exchanger; a second opening/closing valve provided in the bypass pipe; An auxiliary heating device for heating the air supplied to the room and a control device are provided, and the control device opens the first on-off valve and closes the second on-off valve, whereby the refrigerant discharged from the compressor is discharged. To the radiator to radiate the heat, and after decompressing the radiated refrigerant with the outdoor expansion valve, the heating mode in which the outdoor heat exchanger absorbs heat, the outdoor expansion valve is fully closed, and the first on-off valve is closed, By opening the second on-off valve, the refrigerant discharged from the compressor is made to flow to the outdoor heat exchanger through the bypass pipe to radiate the heat, and the radiated refrigerant is decompressed and then absorbed by the heat absorber and auxiliary heating is performed. In a vehicle air conditioner that switches and executes a dehumidifying and heating mode that heats the device, when the control device switches the heating mode to the dehumidifying and heating mode, after reducing the pressure difference across the second on-off valve, the second Since the noise reduction control is performed by opening the on-off valve of the above, closing the first on-off valve, and fully closing the outdoor expansion valve, the second on-off valve is opened when switching from the heating mode to the dehumidification heating mode. At this time, it is possible to significantly suppress or eliminate the sudden flow of the refrigerant through the bypass pipe toward the outdoor heat exchanger. As a result, when switching from the heating mode to the dehumidifying heating mode, it is possible to eliminate or reduce the noise generated when the second opening/closing valve is opened.

In this case, the controller reduces the pressure difference before and after the second on-off valve by increasing the valve opening degree of the outdoor expansion valve and controlling the rotation speed of the compressor in the noise improvement control. If the difference is equal to or less than a predetermined value, opening the second on-off valve closes the first on-off valve, since the outdoor expansion valve so as to fully closed by the valve opening degree expansion of the outdoor expansion valve By increasing the pressure on the refrigerant downstream side of the second on-off valve and decreasing the pressure on the refrigerant upstream side of the second on-off valve by controlling the rotation speed of the compressor, the pressure difference before and after the second on-off valve is effectively reduced. It is possible to reduce the size and quickly switch to the dehumidifying and heating mode, and effectively eliminate or reduce the noise generated during the switching.

In particular, the control device causes the auxiliary heating device to generate heat when switching from the heating mode to the dehumidifying heating mode, and when the temperature of the auxiliary heating device becomes equal to or higher than a predetermined value, the refrigerant that has come out of the outdoor heat exchanger is the heat absorber. Since the control of the outdoor expansion valve and the compressor in the noise improvement control is started while switching to the state of flowing into the air conditioner, it is possible to suppress the decrease in the blowout temperature that occurs when switching from the heating mode to the dehumidifying and heating mode. Become.

According to the second aspect of the present invention, the compressor for compressing the refrigerant, the air flow passage through which the air supplied to the vehicle compartment circulates, and the heat radiated from the refrigerant to heat the air supplied to the vehicle interior from the air flow passage. Radiator, a heat absorber for absorbing the refrigerant and cooling the air supplied from the air flow passage into the vehicle interior, an outdoor heat exchanger provided outside the vehicle interior, and an outdoor heat exchanger exiting the radiator. An outdoor expansion valve for reducing the pressure of the refrigerant flowing into the first opening/closing valve, a first opening/closing valve provided between the discharge side of the compressor and the inlet side of the radiator, and a branch on the upstream side of the first opening/closing valve. A bypass pipe for bypassing the radiator and the outdoor expansion valve to allow the refrigerant discharged from the compressor to flow to the outdoor heat exchanger; a second opening/closing valve provided in the bypass pipe; An auxiliary heating device for heating the air supplied to the room and a control device are provided, and the control device opens the first on-off valve and closes the second on-off valve, whereby the refrigerant discharged from the compressor is discharged. To the radiator to radiate the heat, and after decompressing the radiated refrigerant with the outdoor expansion valve, the heating mode in which the outdoor heat exchanger absorbs heat, the outdoor expansion valve is fully closed, and the first on-off valve is closed, By opening the second on-off valve, the refrigerant discharged from the compressor is made to flow to the outdoor heat exchanger through the bypass pipe to radiate the heat, and the radiated refrigerant is decompressed and then absorbed by the heat absorber and auxiliary heating is performed. In a vehicle air conditioner that switches and executes a dehumidifying and heating mode that heats the device, when the control device switches the heating mode to the dehumidifying and heating mode, after reducing the pressure difference across the second on-off valve, the second Since the noise reduction control is performed by opening the on-off valve of the above, closing the first on-off valve, and fully closing the outdoor expansion valve, the second on-off valve is opened when switching from the heating mode to the dehumidification heating mode. At this time, it is possible to significantly suppress or eliminate the sudden flow of the refrigerant through the bypass pipe toward the outdoor heat exchanger. As a result, when switching from the heating mode to the dehumidifying heating mode, it is possible to eliminate or reduce the noise generated when the second opening/closing valve is opened.

Further , in the noise improvement control, the control device reduces the pressure difference before and after the second on-off valve by fully opening the outdoor expansion valve and setting the rotation speed of the compressor to a predetermined low value. When the difference is less than or equal to a predetermined value, or after a predetermined time has elapsed since the number of revolutions of the compressor was set to the low value, the second opening/closing valve is opened, the first opening/closing valve is closed, and the outdoor expansion valve is fully closed Since the outdoor expansion valve is fully opened to increase the pressure on the refrigerant downstream side of the second opening/closing valve and the rotation speed of the compressor is decreased to decrease the pressure on the refrigerant upstream side of the second opening/closing valve. The pressure difference before and after the second on-off valve can be rapidly reduced, the dehumidifying and heating mode can be accurately switched, and the noise generated at the time of switching can be effectively eliminated or reduced.

In particular, the control device causes the auxiliary heating device to generate heat when switching from the heating mode to the dehumidifying heating mode, and when the temperature of the auxiliary heating device becomes equal to or higher than a predetermined value, the refrigerant that has come out of the outdoor heat exchanger is the heat absorber. with switching state flow in. Thus starts the control of the outdoor expansion valve and the compressor in the noise improvement control, as lowering of air temperature that occurs during switching to the dehumidification and heating mode from heating mode can be suppressed Become.

According to the invention of claim 3, the compressor for compressing the refrigerant, the air flow passage through which the air supplied to the vehicle compartment circulates, and the heat radiated from the refrigerant to heat the air supplied to the vehicle interior from the air flow passage. Radiator, a heat absorber for absorbing 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 an outdoor heat exchanger exiting the radiator. An outdoor expansion valve for reducing the pressure of the refrigerant flowing into the first opening/closing valve, a first opening/closing valve provided between the discharge side of the compressor and the inlet side of the radiator, and a branch on the upstream side of the first opening/closing valve. A bypass pipe for bypassing the radiator and the outdoor expansion valve to allow the refrigerant discharged from the compressor to flow to the outdoor heat exchanger; a second opening/closing valve provided in the bypass pipe; An auxiliary heating device for heating the air supplied to the room and a control device are provided, and the control device opens the first on-off valve and closes the second on-off valve, whereby the refrigerant discharged from the compressor is discharged. To the radiator to radiate the heat, and after decompressing the radiated refrigerant with the outdoor expansion valve, the heating mode in which the outdoor heat exchanger absorbs heat, the outdoor expansion valve is fully closed, and the first on-off valve is closed, By opening the second on-off valve, the refrigerant discharged from the compressor is made to flow to the outdoor heat exchanger through the bypass pipe to radiate the heat, and the radiated refrigerant is decompressed and then absorbed by the heat absorber and auxiliary heating is performed. In a vehicle air conditioner that switches and executes a dehumidifying and heating mode that heats the device, when the control device switches from the dehumidifying and heating mode to the heating mode, after reducing the pressure difference across the first opening/closing valve, Since the noise improvement control for opening the on-off valve of the first and closing the second on-off valve is executed, when switching from the dehumidifying heating mode to the heating mode, when the first on-off valve is opened, the heat is directed toward the radiator side. It is possible to significantly suppress or eliminate the sudden flow of the refrigerant. As a result, when switching from the dehumidifying heating mode to the heating mode, it is possible to eliminate or reduce the noise generated when the first opening/closing valve is opened.

In particular, in the heating mode, the refrigerant is opened and the refrigerant discharged from the outdoor heat exchanger is made to be sucked into the compressor, while in the dehumidification heating mode, it is closed and the refrigerant discharged from the outdoor heat exchanger is made to flow to the heat absorber. In the noise improvement control, the control device further includes the opening/closing valve of No. 3, and after the first opening/closing valve is opened and the second opening/closing valve is closed, the pressure difference before and after the third opening/closing valve becomes equal to or less than a predetermined value. In this case, since the third opening/closing valve is opened, when switching from the dehumidifying heating mode to the heating mode, the refrigerant may suddenly flow toward the compressor side when the third opening/closing valve is opened. It can be significantly suppressed or eliminated.

As a result, when switching from the dehumidifying heating mode to the heating mode, it is possible to eliminate or reduce the noise generated when the third opening/closing valve is opened.

In this case, as in the invention of claim 4 controller, the noise improvement control, open the outdoor expansion valve, and to control the rotational speed of the compressor, or the first closing by stopping the compressor By reducing the pressure difference before and after the valve, and when the pressure difference becomes equal to or less than a predetermined value, the first opening/closing valve is opened and the second opening/closing valve is closed, thereby opening the outdoor expansion valve. By increasing the pressure on the refrigerant downstream side of the first on-off valve and lowering the pressure on the refrigerant upstream side of the first on-off valve by controlling the rotation speed of the compressor or stopping it, the pressure difference before and after the first on-off valve. Can be effectively reduced, the heating mode can be quickly switched, and the noise generated at the time of switching can be effectively eliminated or reduced.

The control device as in the invention of claim 5, in noise improvement control, the outdoor expansion valve as a control in the heating mode, and the compressor is reduced the pressure differential across the first on-off valve by stopping If the pressure difference becomes less than or equal to a predetermined value, or if the first on-off valve is opened and the second on-off valve is closed after a lapse of a predetermined time after stopping the compressor, the outdoor expansion valve To increase the pressure on the refrigerant downstream side of the first on-off valve and decrease the pressure on the refrigerant upstream side of the first on-off valve by stopping the compressor, thereby rapidly increasing the pressure difference across the first on-off valve. It becomes possible to reduce the size and switch to the heating mode accurately, and to effectively eliminate or reduce the noise generated at the time of switching .

Furthermore, control device as of the invention of claim 6, in noise improvement control, heating to increase the auxiliary heating device, after opening the third on-off valve, if to reduce the heat generation of the auxiliary heating device It is also possible to suppress a decrease in the blowout temperature that occurs when switching from the dehumidifying heating mode to the heating mode.

In this case, if the control device reduces the heat generation of the auxiliary heating device when the high-pressure side pressure becomes equal to or higher than a predetermined value after opening the third opening/closing valve, as in the invention of claim 7 , After switching to the heating mode, the radiator and auxiliary heating device can be used to heat the passenger compartment until the high-pressure side pressure rises, and the drop in blowout temperature that occurs during switching can be more reliably eliminated. You will be able to realize comfortable vehicle interior heating.

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. 3 is a timing chart of each device for explaining an example of noise improvement control executed by the controller of FIG. 2 when switching from the heating mode to the dehumidifying heating mode. 3 is a timing chart of each device for explaining an example of noise improvement control executed by the controller of FIG. 2 when switching from the dehumidifying heating mode to the heating mode.

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 according to an embodiment of the present invention. A vehicle according to 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 battery power. 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, Each operation mode of the MAX cooling mode (maximum cooling mode) is 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 for decompressing and expanding the refrigerant during heating, and a heat exchange between the refrigerant and the outside air, which 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 composed of a motor-operated valve for decompressing and expanding the refrigerant, and a heat absorber 9 provided in the air flow passage 3 to absorb heat from the inside and outside of the vehicle to the refrigerant during cooling and dehumidification. And the accumulator 12 and the like are sequentially connected by a refrigerant pipe 13 to form a refrigerant circuit R.

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 the 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 coming out of the outdoor heat exchanger 7 is received via a solenoid valve 17 opened during cooling. The refrigerant pipe 13</b>B on the outlet side of the supercooling unit 16 connected to the dryer unit 14 is connected to the inlet side of the heat absorber 9 via the indoor expansion valve 8. 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 branches into a refrigerant pipe 13D, and this branched refrigerant pipe 13D is located downstream of the internal heat exchanger 19 via a solenoid valve 21 opened during heating. Is connected to the refrigerant pipe 13C. 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.

An electromagnetic valve 30 (constituting a flow path switching device) that is closed during dehumidifying heating and MAX cooling described below is provided in the refrigerant pipe 13G between the discharge side of the compressor 2 and the inlet side of the radiator 4. There is. In this case, the refrigerant pipe 13G is branched to the bypass pipe 35 on the upstream side of the electromagnetic valve 30, and the bypass pipe 35 is opened during dehumidification heating and MAX cooling (also constitutes a flow path switching device). ) Is connected to the refrigerant pipe 13E on the downstream side of the outdoor expansion valve 6 via the. The bypass pipe 35, the solenoid valve 30, and the solenoid valve 40 constitute a bypass device 45 in the present invention.

By configuring the bypass device 45 with the bypass pipe 35, the solenoid valve 30, and the solenoid valve 40, the dehumidification heating mode or MAX in which the refrigerant discharged from the compressor 2 directly flows into the outdoor heat exchanger 7 as described later. This makes it possible to smoothly switch between the cooling mode and the heating mode in which the refrigerant discharged from the compressor 2 flows into the radiator 4, the dehumidifying cooling mode, or the cooling mode.

Further, the air flow passage 3 on the air upstream side of the heat absorber 9 is formed with respective intake ports of an outside air intake port and an inside air intake port (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.

Further, in FIG. 1, reference numeral 23 is 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 air 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 blower outlet 29 is provided with a blower outlet switching damper 31 for controlling the blowout of air from each of the blower outlets.

Next, in FIG. 2, reference numeral 32 denotes a controller (ECU) as a control device composed of a microcomputer, which 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 passenger compartment, an indoor CO ₂ concentration sensor 39 for detecting the carbon dioxide concentration in the passenger compartment, and a blowout port 29 into the passenger compartment. An outlet temperature sensor 41 for detecting the temperature of the air to be discharged, a discharge pressure sensor 42 for detecting the discharge refrigerant pressure (discharge pressure Pd) of the compressor 2, and 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, a suction temperature sensor 55 for detecting the suction refrigerant temperature of the compressor 2, and the temperature of the radiator 4 (the temperature of the air passing through the radiator 4, or Radiator temperature sensor 46 for detecting the temperature of radiator 4 itself: radiator temperature TH, and the refrigerant pressure of radiator 4 (pressure of the refrigerant in radiator 4 or immediately after leaving radiator 4: radiator) A radiator pressure sensor 47 for detecting the pressure PCI) and a heat absorber temperature sensor 48 for detecting the temperature of the heat absorber 9 (the temperature of the air passing through the heat absorber 9 or the temperature of the heat absorber 9 itself: the heat absorber temperature Te). And a heat absorber pressure sensor 49 for detecting the refrigerant pressure of the heat absorber 9 (the pressure of the refrigerant inside the heat absorber 9 or immediately after leaving the heat absorber 9), and for detecting the amount of solar radiation into the vehicle interior, for example A photo sensor type solar radiation sensor 51, a vehicle speed sensor 52 for detecting the 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, and outdoor heat exchange. An outdoor heat exchanger temperature sensor 54 for detecting the temperature of the heat exchanger 7 (the temperature of the refrigerant immediately after it exits the outdoor heat exchanger 7 or the temperature of the outdoor heat exchanger 7 itself: the outdoor heat exchanger temperature TXO); Each of the outdoor heat exchanger pressure sensors 56 for detecting the refrigerant pressure of the heat exchanger 7 (the pressure of the refrigerant inside the outdoor heat exchanger 7 or immediately after exiting from the outdoor heat exchanger 7: the outdoor heat exchanger pressure PXO). The output 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. Solenoid valve of valve 6, indoor expansion valve 8, auxiliary heater 23, solenoid valve 30 (for dehumidification), solenoid valve 17 (for cooling), solenoid valve 21 (for heating), solenoid valve 40 (also for dehumidification) Are connected. 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, and a MAX cooling mode (maximum cooling 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), and the solenoid valve 21 is opened. Close 17 (for cooling). Further, the solenoid valve 30 (for dehumidification) is opened and the solenoid valve 40 (for dehumidification) 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 through 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 (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 by 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 solenoid 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. The supercooling degree SC of the refrigerant at the outlet of the radiator 4 is controlled. 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 in this heating mode, the controller 32 assists to supplement the shortage with the heat generated by the auxiliary heater 23. The energization of the heater 23 is controlled. Thereby, a 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 disposing the auxiliary heater 23 on the upstream side of the radiator 4 in the air, Thus, the capability of the auxiliary heater 23 composed of 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 valve 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 through 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 run there or by being cooled 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, 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 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 backward from the outdoor expansion valve 6 into the radiator 4. Becomes As a result, it becomes 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 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. While 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 from the air outlet 29 into the vehicle interior is accurately prevented.

This makes it possible to control the temperature of the air blown into the vehicle interior to an appropriate heating temperature while dehumidifying the air, and to realize comfortable and efficient dehumidification heating in the vehicle interior. Further, as described above, in the dehumidifying and heating mode, the air mix damper 28 is in a state where 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 is possible to improve the energy saving performance 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 will pass 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, it is possible to suppress the temperature of the air blown into the vehicle interior by the radiator 4 from decreasing, and improve the COP.

(3) Dehumidifying and Cooling Mode Next, in the dehumidifying and cooling mode, the controller 32 opens the solenoid valve 17 and closes the solenoid 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 through 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 radiator 4 is ventilated with the air in the air passage 3, the air in the air 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 by a slight opening. The refrigerant that has flowed into the outdoor heat exchanger 7 is condensed by being run there or by being cooled 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 moisture in the air blown out from the indoor blower 27 is condensed and attached to the heat absorber 9 by the heat absorbing action at this time, 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 that has been cooled by the heat absorber 9 and dehumidified is reheated in the process of passing through the radiator 4 (has a lower heat radiation capacity than during heating). It 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 opening degree of the valve 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 state of the dehumidifying and cooling mode. Note that 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 high-pressure gas refrigerant discharged from the compressor 2 flows into the radiator 4 from the refrigerant pipe 13G via the solenoid valve 30, and the refrigerant exiting the radiator 4 passes through the refrigerant pipe 13E to the outdoor expansion valve 6. 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 moisture 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 valve 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 makes the air in the air flow passage 3 not pass through 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 run there or by being cooled 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 similarly 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. .. As a result, it becomes 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 cooled by 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, powerful 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 of operation mode The air flowing through the air flow passage 3 is cooled by the heat absorber 9 and heated by the radiator 4 (and the auxiliary heater 23) in each operation mode (adjusted by the air mix damper 28). ) And is blown out into the vehicle compartment from the air outlet 29. The controller 32 is set by the air-conditioning operation unit 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 interior, 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/absence of a dehumidification request in the vehicle interior. By switching each operation mode based on parameters such as, etc., the heating mode, dehumidification heating mode, dehumidification cooling mode, cooling mode and MAX cooling mode can be accurately switched according to the environmental conditions and the necessity of dehumidification. Achieves efficient vehicle interior air conditioning.

(7) Noise improvement control when switching from heating mode to dehumidification heating mode Next, referring to FIG. 4, when switching the operation mode of the vehicle air conditioner 1 from the heating mode described above to the dehumidification heating mode. An example of the noise improvement control executed by the controller 32 will be described. The timing chart of FIG. 4 shows the pressure difference ΔPdx before and after the electromagnetic valve 40 (the second opening/closing valve of the present invention) when switching from the heating mode to the dehumidifying and heating mode, and the blowout temperature detected by the blowout temperature sensor 41 (described above). The temperature of the air blown into the vehicle compartment from the air outlet 29), the auxiliary heater temperature Tptc detected by the auxiliary heater temperature sensor 50, the rotational speed NC of the compressor 2, the valve opening degree of the outdoor expansion valve 6, Output of auxiliary heater 23 (amount of energization or amount of heat generation), solenoid valve 40, solenoid valve 30 (first opening/closing valve of the present invention), solenoid valve 17, and solenoid valve 21 (third opening/closing valve of the present invention) Shows the state of.

The pressure difference ΔPdx before and after the solenoid valve 40 (second opening/closing valve) is determined by the pressure Pd on the refrigerant upstream side (front) of the solenoid valve 40 detected by the discharge pressure sensor 42 and the outdoor heat exchanger temperature sensor 54. The outdoor heat exchanger pressure PXO on the refrigerant downstream side (rear side) of the solenoid valve 40, which is converted from the temperature of the refrigerant immediately after it is detected from the outdoor heat exchanger 7 (outdoor heat exchanger temperature TXO) (outdoor as in the embodiment) When the heat exchanger pressure sensor 56 is provided, the difference (ΔPdx=Pd−PXO) from the outdoor heat exchanger pressure PCO detected by the outdoor heat exchanger pressure sensor 56 may be used, The controller 32 calculates.

The controller 32 also calculates a pressure difference ΔPix before and after the electromagnetic valve 30 (first opening/closing valve) in the noise improvement control described later. In this case, the controller 32 uses the pressure Pd on the refrigerant upstream side (front) of the solenoid valve 30 detected by the discharge pressure sensor 42 and the pressure on the refrigerant downstream side (rear) of the solenoid valve 30 detected by the radiator pressure sensor 47. Based on a certain radiator pressure PCI, the difference ΔPix (ΔPix=Pd−PCI) between them is used as the pressure difference before and after the solenoid valve 30.

Further, the controller 32 also calculates a pressure difference ΔPxs before and after the electromagnetic valve 21 (third opening/closing valve) in the noise improvement control described later. In this case, the controller 32 causes the refrigerant upstream side of the solenoid valve 21 (the outdoor heat exchanger temperature TXO) converted from the temperature of the refrigerant (outdoor heat exchanger temperature TXO) immediately after exiting from the outdoor heat exchanger 7 detected by the outdoor heat exchanger temperature sensor 54 ( (Before) the outdoor heat exchanger pressure PXO (when the outdoor heat exchanger pressure sensor 56 is provided as in the embodiment, the outdoor heat exchanger pressure PCO detected by the outdoor heat exchanger pressure sensor 56 is also used. Good) and the suction pressure Ps on the refrigerant downstream side (rear side) of the solenoid valve 21 calculated from the suction temperature of the compressor 2 detected by the suction temperature sensor 55 (ΔPxs=PXO-Ps). The pressure difference between the front and back is used (the same applies to the noise improvement control below).

(7-1) Noise improvement control when switching from heating mode to dehumidifying heating mode (Part 1)
When the operation mode is switched from the heating mode to the dehumidifying heating mode, the pressure difference ΔPdx before and after the solenoid valve 40 has a large value in the heating mode as shown in FIG. 4. Therefore, when the electromagnetic valve 40 that is closed in the heating mode is opened to enter the dehumidifying and heating mode with the pressure difference concerned, the direction from the discharge side of the compressor 2 to the inlet side of the outdoor heat exchanger 7 via the electromagnetic valve 40. Then, the refrigerant rapidly flows in the bypass pipe 35, and a large noise (noise) is generated in the solenoid valve 40.

Therefore, when the operation mode is switched from the heating mode to the dehumidifying heating mode, the controller 32 executes the noise improvement control described below. When switching from the heating mode to the dehumidifying heating mode, the controller 32 first causes the auxiliary heater 23 to generate heat and increase its output (amount of energization or amount of heat generation). In this case, the controller 32 increases the output of the auxiliary heater 23 in the dehumidifying and heating mode to a predetermined value D (FIG. 4) which is higher than the target value C (FIG. 4) by a predetermined value. As a result, the auxiliary heater temperature Tptc increases.

Then, when the auxiliary heater temperature Tptc becomes equal to or higher than the predetermined value B in FIG. 4, the controller 32 opens the solenoid valve 17 and closes the solenoid valve 21. As a result, the refrigerant circuit R is switched to a state in which the refrigerant discharged from the outdoor heat exchanger 7 flows to the heat absorber 9 via the receiver dryer unit 14, the supercooling unit 16, the internal heat exchanger 19, and the indoor expansion valve 8. The controller 32 then controls the output of the auxiliary heater 23 to the target value C in the dehumidifying and heating mode described above.

Further, when the auxiliary heater temperature Tptc becomes equal to or higher than the predetermined value B, the controller 32, in the embodiment, changes the pressure difference Pdx before and after the solenoid valve 40 to the predetermined value A (for example, before switching the solenoid valve 40 and the solenoid valve 30). The valve opening degree of the outdoor expansion valve 6 is increased and the rotational speed NC of the compressor 2 is adjusted (controlled to decrease) so as to be 0.2 MPa or less). By increasing the valve opening degree of the outdoor expansion valve 6, the outdoor heat exchanger pressure PXO rises, and by controlling the rotational speed NC of the compressor 2 in the direction of lowering it, the discharge pressure Pd lowers. The pressure difference Pdx (=Pd-PXO) before and after the valve 40 becomes smaller.

Then, when the pressure difference ΔPdx is reduced to the predetermined value A or less in FIG. 4, the controller 32 opens the solenoid valve 40, closes the solenoid valve 30, and fully closes the outdoor expansion valve 6 to control the compressor 2. By performing the control during dehumidification heating, the air conditioning operation in the dehumidification heating mode is performed.

(7-2) Noise improvement control when switching from heating mode to dehumidifying heating mode (Part 2)
Here, in the noise improvement control of the above-described embodiment, the controller 32 enlarges the valve opening degree of the outdoor expansion valve 6 so that the pressure difference ΔPdx before and after the solenoid valve 40 becomes the predetermined value A or less, and the compressor 2 However, the invention is not limited to this, but the valve opening degree of the outdoor expansion valve 6 is fully opened (FIG. 4), and the rotation speed NC of the compressor 2 is a predetermined low rotation speed. It may be set to NC1 (FIG. 4. For example, 800 rpm). By fully opening the outdoor expansion valve 6 and controlling the rotational speed NC of the compressor 2 to a low predetermined rotational speed NC1, the outdoor heat exchanger pressure PXO increases and the discharge pressure Pd decreases, so the solenoid valve 40 The pressure difference Pdx between before and after becomes smaller. Also in this case, when the pressure difference ΔPdx is reduced to the predetermined value A or less, the controller 32 opens the solenoid valve 40, closes the solenoid valve 30, and fully closes the outdoor expansion valve 6, thereby dehumidifying. Shift to air conditioning operation in heating mode.

(7-3) Noise improvement control when switching from heating mode to dehumidifying heating mode (Part 3)
Further, in the noise improvement control, the controller 32 fully opens the outdoor expansion valve 6 and sets the rotation speed NC of the compressor 2 to the predetermined rotation speed NC1 for a predetermined time (for example, 10 seconds, FIG. 4). After a lapse of time, the electromagnetic valve 40 may be opened, the electromagnetic valve 30 may be closed, and the outdoor expansion valve 6 may be fully closed to start the air conditioning operation in the dehumidifying and heating mode.

As described above, when the operation mode is switched from the heating mode to the dehumidifying and heating mode, the controller 32 reduces the pressure difference ΔPdx before and after the electromagnetic valve 40 (second opening/closing valve), and then opens the electromagnetic valve 40 to open the electromagnetic valve 30. Since the (first opening/closing valve) is closed and the outdoor expansion valve 6 is fully closed, the noise improvement control is executed. Therefore, when the heating mode is switched to the dehumidifying and heating mode, the bypass is provided when the electromagnetic valve 40 is opened. It is possible to significantly suppress or eliminate the sudden flow of the refrigerant through the pipe 35 toward the outdoor heat exchanger 7 side. As a result, when switching from the heating mode to the dehumidifying heating mode, it is possible to eliminate or reduce the noise generated when the electromagnetic valve 40 is opened.

In particular, in the noise improvement control (noise improvement control at the time of switching from the heating mode to the dehumidifying and heating mode (1)), the controller 32 enlarges the valve opening degree of the outdoor expansion valve 6 and rotates the compressor 2. By controlling the number NC, the pressure difference ΔPdx before and after the solenoid valve 40 is reduced, and when the pressure difference ΔPdx becomes a predetermined value A or less, the solenoid valve 40 is opened, the solenoid valve 30 is closed, and the outdoor expansion is performed. Since the valve 6 is fully closed, the pressure on the refrigerant downstream side of the electromagnetic valve 40 is increased by increasing the valve opening degree of the outdoor expansion valve 6, and the refrigerant upstream of the electromagnetic valve 40 is controlled by controlling the rotational speed NC of the compressor 2. By lowering the pressure on the side, the pressure difference ΔPdx before and after the solenoid valve 40 can be effectively reduced, the dehumidifying and heating mode can be quickly switched, and noise generated at the time of switching can be effectively eliminated or reduced. You will be able to.

Further, in the noise improvement control (noise improvement control at the time of switching from the heating mode to the dehumidifying and heating mode (No. 2) and (No. 3)), the controller 32 fully opens the outdoor expansion valve 6 and the compressor 2 of the compressor 2. The pressure difference ΔPdx before and after the solenoid valve 40 is reduced by setting the rotation speed NC to a predetermined low value, and when the pressure difference ΔPdx becomes equal to or less than the predetermined value A, or the rotation speed NC of the compressor 2. Since the solenoid valve 40 is opened, the solenoid valve 30 is closed, and the outdoor expansion valve 6 is fully closed after a predetermined time has elapsed since the value of was set to a low value, the outdoor expansion valve 6 is fully opened, so By increasing the pressure and decreasing the rotational speed NC of the compressor 2 to decrease the pressure on the refrigerant upstream side of the solenoid valve 40, the pressure difference ΔPdx before and after the solenoid valve 40 is rapidly reduced, and the dehumidification heating mode is accurately switched. Moreover, it is possible to effectively eliminate or reduce the noise generated at the time of switching.

Here, in the noise improvement control, since the rotation speed NC of the compressor 2 decreases, there is a risk that the temperature of the air blown into the vehicle interior (blowout temperature) decreases and comfort deteriorates. However, as described above, in the embodiment, when the controller 32 switches from the heating mode to the dehumidifying and heating mode, the auxiliary heater 23 is first caused to generate heat, and when the temperature Tptc of the auxiliary heater 23 becomes equal to or higher than the predetermined value B, the outdoor heat is generated. Since the solenoid valve 17 and the solenoid valve 21 are switched to a state in which the refrigerant discharged from the exchanger 7 is made to flow to the heat absorber 9, the control of the outdoor expansion valve 6 and the compressor 2 in the noise improvement control is started. As shown in, the blowout temperature is maintained substantially constant even in the process of switching from the heating mode to the dehumidifying and heating mode. As a result, a decrease in the blowout temperature that occurs when the heating mode is switched to the dehumidifying and heating mode is suppressed, and a comfortable vehicle interior air conditioning can be realized.

(8) Noise improvement control when switching from dehumidifying heating mode to heating mode Next, referring to FIG. 5, when switching the operation mode of the vehicle air conditioner 1 from the dehumidifying heating mode to the heating mode described above. An example of the noise improvement control executed by the controller 32 will be described. The timing chart of FIG. 5 shows the pressure difference ΔPxs before and after the electromagnetic valve 21 (the third opening/closing valve of the present invention) when switching from the dehumidifying heating mode to the heating mode, and the electromagnetic valve 30 (the first opening/closing of the present invention). Pressure difference ΔPix before and after the valve), the blow-out temperature described above, the auxiliary heater temperature Tptc, the rotational speed NC of the compressor 2, the valve opening degree of the outdoor expansion valve 6, the output of the auxiliary heater 23, and the solenoid valve. 40 (state of the second opening/closing valve of the present invention), the solenoid valve 30, the solenoid valve 17, and the solenoid valve 21 are shown. The pressure difference ΔPxs before and after the solenoid valve 21 and the pressure difference ΔPix before and after the solenoid valve 30 are calculated by the controller 32 as described above.

(8-1) Noise improvement control when switching from dehumidifying heating mode to heating mode (Part 1)
When the operation mode is switched from the dehumidifying heating mode to the heating mode, the pressure difference ΔPix before and after the solenoid valve 30 has a large value in the dehumidifying heating mode, as shown in FIG. Therefore, when the electromagnetic valve 30 that is closed in the dehumidifying heating mode is opened to keep the pressure difference at the heating mode, the refrigerant flows from the discharge side of the compressor 2 to the inlet side of the radiator 4 via the electromagnetic valve 30. The refrigerant rapidly flows in the pipe 13G, and a large noise (noise) is generated in the solenoid valve 30.

In the dehumidification heating mode, the pressure difference ΔPxs before and after the solenoid valve 21 is also a large value as shown in FIG. Therefore, when the solenoid valve 21 that is closed in the dehumidifying heating mode is opened to keep the pressure difference at the heating mode, the refrigerant rapidly flows from the outdoor heat exchanger 7 to the inlet side of the accumulator 12 via the solenoid valve 21. Similarly, a large noise (noise) is generated in the solenoid valve 21.

Therefore, the controller 32 also executes the noise improvement control described below when switching the operation mode from the dehumidifying heating mode to the heating mode. When switching from the dehumidifying heating mode to the heating mode, the controller 32 first increases the output (amount of energization or amount of heat generation) of the auxiliary heater 23. In this case, the controller 32 increases the output of the auxiliary heater 23 to a predetermined value D (FIG. 5) that is higher than the target value C (FIG. 5) of the output of the auxiliary heater 23 that is being executed in the dehumidification heating mode. Let As a result, the auxiliary heater temperature Tptc rises.

In addition, before switching the solenoid valve 40 and the solenoid valve 30, in the embodiment, the controller 32 performs outdoor expansion so that the pressure difference Pix before and after the solenoid valve 30 becomes equal to or less than a predetermined value A (for example, 0.2 MPa). The valve 6 is changed from the closed state to the open state, and the rotational speed NC of the compressor 2 is adjusted (controlled to decrease). By opening the outdoor expansion valve 6, the radiator pressure PCI rises, and by controlling the rotational speed NC of the compressor 2 in a direction of lowering it, the discharge pressure Pd falls, so the pressure difference across the solenoid valve 30 is reduced. Pix (=Pd-PCI) becomes smaller.

Then, when the pressure difference ΔPix is reduced to the predetermined value A or less in FIG. 5, the controller 32 opens the solenoid valve 30 and closes the solenoid valve 40. Since the solenoid valve 30 is opened and the solenoid valve 40 is closed, the refrigerant is decompressed by the outdoor expansion valve 6 via the radiator 4, so that the outdoor heat exchanger pressure PXO is reduced. The pressure difference ΔPxs (=PXO-Ps) before and after the valve 21 also becomes smaller. Then, the controller 32 opens the solenoid valve 21 and closes the solenoid valve 17 when the pressure difference ΔPxs before and after the solenoid valve 21 is reduced to a predetermined value E or less in FIG. Thereby, the refrigerant circuit R is switched to a state in which the refrigerant discharged from the outdoor heat exchanger 7 flows to the accumulator 12. Further, the output (heat generation) of the auxiliary heater 23 is also reduced (the output is stopped in this embodiment), and the heating mode is shifted to the air conditioning operation.

(8-2) Noise improvement control when switching from dehumidification heating mode to heating mode (Part 2)
Here, in the noise improvement control of the above-described embodiment, the controller 32 opens the outdoor expansion valve 6 so that the pressure difference ΔPix before and after the solenoid valve 30 becomes equal to or less than the predetermined value A, and the rotation speed NC of the compressor 2 is changed. However, if the pressure difference ΔPix does not fall below the predetermined value A, the compressor 2 may be stopped (that is, the outdoor expansion valve 6 may be opened and the compressor 2 may be stopped). (Fig. 5). By opening the outdoor expansion valve 6 and stopping the compressor 2, the radiator pressure PCI and the discharge pressure Pd go toward an equilibrium state, so the pressure difference Pix before and after the solenoid valve 30 becomes smaller.

Then, when the pressure difference ΔPix is reduced to the predetermined value A or less, the controller 32 opens the solenoid valve 30 and closes the solenoid valve 40. Then, the pressure difference ΔPxs before and after the solenoid valve 21 becomes equal to or less than the predetermined value E, the solenoid valve 17 is closed, the solenoid valve 21 is opened, the compressor 2 is started, and the output of the auxiliary heater 23 is also reduced (in the embodiment, in the embodiment). Stop the output) and shift to air conditioning operation in heating mode.

(8-3) Noise improvement control when switching from dehumidifying heating mode to heating mode (Part 3)
In addition to this, the controller 32 may shift the outdoor expansion valve 6 to the control state in the heating mode from the start of the noise improvement control in this case (FIG. 5), and the compressor 2 may be stopped ( (Figure 5). Since the outdoor expansion valve 6 is opened to enter the control state during heating and the compressor 2 is stopped, the radiator pressure PCI and the discharge pressure Pd move toward the equilibrium state, so that the pressure difference Pix before and after the solenoid valve 30 is reduced. It gets smaller.

Then, when the pressure difference ΔPix is reduced to the predetermined value A or less, the controller 32 opens the solenoid valve 30 and closes the solenoid valve 40. Then, the pressure difference ΔPxs before and after the solenoid valve 21 becomes equal to or less than the predetermined value E, the solenoid valve 17 is closed, the solenoid valve 21 is opened, the compressor 2 is started, and the output of the auxiliary heater 23 is also reduced (in the embodiment, in the embodiment). Stop the output) and shift to air conditioning operation in heating mode.

(8-4) Noise improvement control when switching from dehumidifying heating mode to heating mode (Part 4)
In the noise improvement control, the controller 32 sets the outdoor expansion valve 6 to the control state during heating, and after the compressor 2 is stopped, a predetermined time (for example, 10 seconds, e.g., FIG. 5) elapses. The solenoid valve 30 may be opened and the solenoid valve 40 may be closed. Also in that case, the pressure difference ΔPxs before and after the electromagnetic valve 21 becomes equal to or less than the predetermined value E, the electromagnetic valve 17 is closed, the electromagnetic valve 21 is opened, the compressor 2 is started, and the output of the auxiliary heater 23 is also reduced. In the example, stop the output) and shift to the air conditioning operation in the heating mode.

Thus, when switching from the dehumidification heating mode to the heating mode, the controller 32 reduces the pressure difference ΔPix before and after the electromagnetic valve 30, then opens the electromagnetic valve 30 and closes the electromagnetic valve 40. Therefore, when switching from the dehumidifying heating mode to the heating mode, when the solenoid valve 30 is opened, the rapid flow of the refrigerant toward the radiator 4 side can be significantly suppressed or eliminated. This makes it possible to eliminate or reduce the noise generated when the solenoid valve 30 is opened when switching from the dehumidifying heating mode to the heating mode.

Particularly, in the noise improvement control (noise improvement control when switching from the dehumidifying heating mode to the heating mode (No. 1) and (No. 2)), the controller 32 opens the outdoor expansion valve 6 in the noise improving control, and When the pressure difference ΔPix before and after the solenoid valve 30 is reduced by controlling the rotation speed NC of the compressor 2 or by stopping the compressor 2, when the pressure difference ΔPix becomes a predetermined value A or less, Since the solenoid valve 30 is opened and the solenoid valve 40 is closed, the pressure on the refrigerant downstream side of the solenoid valve 30 is increased by opening the outdoor expansion valve 6, and the rotation speed of the compressor 2 is controlled, or the solenoid valve 30 is stopped. By lowering the pressure on the refrigerant upstream side, the pressure difference across the solenoid valve 30 can be effectively reduced, the heating mode can be quickly switched, and the noise generated at the time of switching can be effectively eliminated or reduced. You will be able to.

In the noise improvement control (noise improvement control when switching from the dehumidification heating mode to the heating mode (Part 3) and (Part 4)), the controller 32 sets the outdoor expansion valve 6 in the heating mode in the noise improvement control. The pressure difference ΔPix before and after the solenoid valve 30 is reduced by controlling and stopping the compressor 2, and when the pressure difference ΔPix becomes a predetermined value A or less, or the compressor 2 is stopped. Since the solenoid valve 30 is opened and the solenoid valve 40 is closed after a predetermined time has elapsed, the pressure on the refrigerant downstream side of the solenoid valve 30 is increased by opening the outdoor expansion valve 6, and the refrigerant upstream side of the solenoid valve 30 is stopped by stopping the compressor 2. The pressure difference ΔPix before and after the solenoid valve 30 can be quickly reduced by lowering the pressure of, and the heating mode can be accurately switched, and the noise generated at the time of switching can be effectively eliminated or reduced. ..

Further, in addition to the noise improvement control in this case, the controller 32 opens the solenoid valve 30 and closes the solenoid valve 40, and when the pressure difference ΔPxs before and after the solenoid valve 21 becomes equal to or less than the predetermined value E, Since the solenoid valve 21 is opened and the solenoid valve 17 is opened, when switching from the dehumidification heating mode to the heating mode, when the solenoid valve 21 is opened, the refrigerant may suddenly flow toward the compressor 2 side. It can be significantly suppressed or eliminated. As a result, when switching from the dehumidifying heating mode to the heating mode, the noise generated when the electromagnetic valve 21 is opened can be eliminated or reduced.

Here, even in the noise improvement control, since the rotation speed NC of the compressor 2 is reduced or stopped, there is a risk that the temperature of the air blown into the passenger compartment (blowing temperature) is lowered and comfort is deteriorated. is there. However, in the embodiment, when switching from the dehumidifying heating mode to the heating mode, the controller 32 first increases the heat generation of the auxiliary heater 23, opens the solenoid valve 21, and then reduces (stops) the heat generation. As shown in FIG. 5, the blowout temperature is maintained substantially constant even in the process of switching from the dehumidifying heating mode to the heating mode. As a result, it is possible to suppress a decrease in the outlet temperature that occurs when switching from the dehumidifying heating mode to the heating mode, and to realize comfortable vehicle interior air conditioning.

(8-5) Noise improvement control when switching from dehumidifying heating mode to heating mode (Part 5)
Here, in the noise improvement control when switching from the dehumidifying heating mode to the heating mode, the controller 32 reduces the heat generation of the auxiliary heater 23 (stops in the embodiment) after opening the solenoid valve 21, Not limited to that, the auxiliary heater 23 is caused to generate heat even after shifting to the heating mode, and, for example, the radiator pressure PCI (high-pressure side pressure, which may be the radiator temperature TH) rises above a predetermined value (which may be the target value). Thus, the heat generation may be reduced (including stop). Accordingly, after switching to the heating mode, the interior of the vehicle can be heated by the radiator 4 and the auxiliary heater 23 until the pressure on the high-pressure side of the refrigerant circuit R rises. It is possible to more surely eliminate the decrease and realize comfortable vehicle interior heating.

In the noise improvement control at the time of switching from the dehumidifying heating mode to the heating mode as described above, the air volume of the indoor blower 27 is reduced, and after the mode is changed to the heating mode, the radiator pressure PCI (or the radiator temperature TH is the target value. It is also possible to return to the original air volume after the temperature rises to 1. By reducing the air volume of the indoor blower 27, it becomes possible to further suppress the decrease in the blowout temperature.

Further, in the embodiment, the present invention is applied to the vehicle air conditioner 1 that switches and executes each operation mode of the heating mode, the dehumidifying heating mode, the dehumidifying cooling mode, the cooling mode, and the MAX cooling mode, but is not limited thereto. The present invention is also effective for a vehicle air conditioner that switches between a heating mode and a dehumidifying and heating mode and executes the mode.

Further, the switching control of each operation mode shown in the embodiment is not limited to that, and depending on the capacity of the vehicle air conditioner and the usage environment, the outside air temperature Tam, the humidity in the vehicle compartment, the target outlet temperature TAO, 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.

Furthermore, the auxiliary heating device is not limited to the auxiliary heater 23 shown in the embodiment, but a heat medium circulation circuit for circulating the heat medium heated by the heater to heat the air in the air flow passage, an engine, or the like. You may utilize the heater core etc. which circulate the radiator water heated by. Further, it goes without saying that the configuration of the refrigerant circuit R described in each of the above embodiments is not limited to that, and can be changed without 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 21 Solenoid Valve (Third Open/Close Valve)
23 Auxiliary heater (auxiliary heating device)
27 Indoor blower (blower fan)
28 Air mix damper 30 Solenoid valve (first opening/closing valve)
40 Solenoid valve (second on-off valve)
31 blower outlet switching damper 32 controller (control device)
35 bypass piping 45 bypass device R refrigerant circuit

Claims (7)

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 to the vehicle compartment from the air flow passage,
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 compartment,
An outdoor expansion valve for decompressing the refrigerant flowing out of the radiator and flowing into the outdoor heat exchanger,
A first on-off valve provided between the discharge side of the compressor and the inlet side of the radiator;
A bypass pipe that branches on the upstream side of the first on-off valve, bypasses the radiator and the outdoor expansion valve, and causes the refrigerant discharged from the compressor to flow to the outdoor heat exchanger;
A second on-off valve provided in the bypass pipe;
An auxiliary heating device for heating the air supplied to the vehicle compartment from the air flow passage,
Equipped with a control device,
By the control device opening the first on-off valve and closing the second on-off valve, the refrigerant discharged from the compressor is caused to flow to the radiator to radiate the heat, and the radiated refrigerant is released to the outside of the room. After decompressing with an expansion valve, a heating mode for absorbing heat with the outdoor heat exchanger,
By fully closing the outdoor expansion valve, closing the first opening/closing valve, and opening the second opening/closing valve, the refrigerant discharged from the compressor is caused to flow to the outdoor heat exchanger through the bypass pipe. In a vehicle air conditioner that heat-dissipates and decompresses the heat-dissipated refrigerant, causes the heat absorber to absorb heat, and switches and executes a dehumidifying and heating mode that causes the auxiliary heating device to generate heat.
When switching from the heating mode to the dehumidifying heating mode, the control device causes the auxiliary heating device to generate heat, and when the temperature of the auxiliary heating device is equal to or higher than a predetermined value, the refrigerant that has exited from the outdoor heat exchanger. While switching to the state of flowing into the heat absorber,
When the pressure difference before and after the second on-off valve is reduced by increasing the valve opening of the outdoor expansion valve and controlling the rotation speed of the compressor, and the pressure difference becomes equal to or less than a predetermined value. In addition, the vehicle air conditioner is characterized in that the noise improvement control is started in which the second opening/closing valve is opened, the first opening/closing valve is closed, and the outdoor expansion valve is fully closed. 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 to the vehicle compartment from the air flow passage,
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 compartment,
An outdoor expansion valve for decompressing the refrigerant flowing out of the radiator and flowing into the outdoor heat exchanger,
A first on-off valve provided between the discharge side of the compressor and the inlet side of the radiator;
A bypass pipe that branches on the upstream side of the first on-off valve, bypasses the radiator and the outdoor expansion valve, and causes the refrigerant discharged from the compressor to flow to the outdoor heat exchanger;
A second on-off valve provided in the bypass pipe;
An auxiliary heating device for heating the air supplied to the vehicle compartment from the air flow passage,
Equipped with a control device,
By the control device opening the first on-off valve and closing the second on-off valve, the refrigerant discharged from the compressor is caused to flow to the radiator to radiate the heat, and the radiated refrigerant is released to the outside of the room. After decompressing with an expansion valve, a heating mode for absorbing heat with the outdoor heat exchanger,
By fully closing the outdoor expansion valve, closing the first opening/closing valve, and opening the second opening/closing valve, the refrigerant discharged from the compressor is caused to flow to the outdoor heat exchanger through the bypass pipe. In a vehicle air conditioner that heat-dissipates and decompresses the heat-dissipated refrigerant, causes the heat absorber to absorb heat, and switches and executes a dehumidifying and heating mode that causes the auxiliary heating device to generate heat.
When switching from the heating mode to the dehumidifying heating mode, the control device causes the auxiliary heating device to generate heat, and when the temperature of the auxiliary heating device is equal to or higher than a predetermined value, the refrigerant that has exited from the outdoor heat exchanger. While switching to the state of flowing into the heat absorber,
The pressure difference before and after the second on-off valve was reduced by fully opening the outdoor expansion valve and setting the rotation speed of the compressor to a predetermined low value, and the pressure difference became a predetermined value or less. In some cases, or after the rotational speed of the compressor is set to the low value, the second opening/closing valve is opened, the first opening/closing valve is closed, and the outdoor expansion valve is fully closed after a lapse of a predetermined time. A vehicle air conditioner characterized by starting control . 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 to the vehicle compartment from the air flow passage,
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 compartment,
An outdoor expansion valve for decompressing the refrigerant flowing out of the radiator and flowing into the outdoor heat exchanger,
A first on-off valve provided between the discharge side of the compressor and the inlet side of the radiator;
A bypass pipe that branches on the upstream side of the first on-off valve, bypasses the radiator and the outdoor expansion valve, and causes the refrigerant discharged from the compressor to flow to the outdoor heat exchanger;
A second on-off valve provided in the bypass pipe;
An auxiliary heating device for heating the air supplied to the vehicle compartment from the air flow passage,
Equipped with a control device,
By the control device opening the first on-off valve and closing the second on-off valve, the refrigerant discharged from the compressor is caused to flow to the radiator to radiate the heat, and the radiated refrigerant is released to the outside of the room. After decompressing with an expansion valve, a heating mode for absorbing heat with the outdoor heat exchanger,
By fully closing the outdoor expansion valve, closing the first opening/closing valve, and opening the second opening/closing valve, the refrigerant discharged from the compressor is caused to flow to the outdoor heat exchanger through the bypass pipe. In a vehicle air conditioner that heat-dissipates and decompresses the heat-dissipated refrigerant, causes the heat absorber to absorb heat, and switches and executes a dehumidifying and heating mode that causes the auxiliary heating device to generate heat.
A state in which the refrigerant that has opened in the heating mode and is in a state that causes the refrigerant that has come out of the outdoor heat exchanger to be sucked into the compressor, and that has the refrigerant that has been closed and that has flowed out of the outdoor heat exchanger in the dehumidifying and heating mode flows to the heat absorber. Further comprising a third on-off valve
When switching from the dehumidifying heating mode to the heating mode, the control device reduces the pressure difference between the front and rear of the first opening/closing valve, then opens the first opening/closing valve and closes the second opening/closing valve. While performing improvement control,
In the noise improvement control, when the pressure difference before and after the third opening/closing valve becomes a predetermined value or less after the first opening/closing valve is opened and the second opening/closing valve is closed, the third opening/closing valve is opened. A vehicle air conditioner characterized by opening an on-off valve . In the noise improvement control, the control device opens the outdoor expansion valve and controls the rotation speed of the compressor, or stops the compressor to cause a pressure difference across the first on-off valve. The air conditioner for a vehicle according to claim 3, wherein the first opening/closing valve is opened and the second opening/closing valve is closed when the pressure difference becomes equal to or less than a predetermined value. .. In the noise improvement control, the control device controls the outdoor expansion valve in the heating mode, and stops the compressor to reduce the pressure difference before and after the first on-off valve, thereby reducing the pressure. 4. The first opening/closing valve is opened and the second opening/closing valve is closed when a difference is equal to or less than a predetermined value or after a lapse of a predetermined time after stopping the compressor. The vehicle air conditioner according to. The control device increases the heat generation of the auxiliary heating device and reduces the heat generation of the auxiliary heating device after opening the third opening/closing valve in the noise improvement control. The vehicle air conditioner according to claim 5 . The vehicle according to claim 6, wherein the control device reduces the heat generation of the auxiliary heating device when the high-pressure side pressure becomes equal to or higher than a predetermined value after opening the third opening/closing valve. Air conditioner.

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