JP6754214B2 - Vehicle air conditioner - Google Patents

Description

The present invention relates to a heat pump type air conditioner for air-conditioning the interior of a vehicle, particularly an air conditioner applicable to a hybrid vehicle or an electric vehicle.

Due to the emergence of environmental problems in recent years, hybrid vehicles and electric vehicles have become widespread. As an air conditioner that can be applied to such a vehicle, a compressor that compresses and discharges the refrigerant, a radiator that is provided on the vehicle interior side to dissipate the refrigerant, and a radiator that is provided on the vehicle interior side are provided. It is equipped with a heat absorber that absorbs the refrigerant and an outdoor heat exchanger that is installed outside the vehicle interior to dissipate or absorb the refrigerant. The refrigerant discharged from the compressor is dissipated in the radiator, and the refrigerant dissipated in this radiator is dissipated. After decompressing with the outdoor expansion valve, the heating mode absorbs heat in the outdoor heat exchanger, and the refrigerant discharged from the compressor is dissipated in the radiator or outdoor heat exchanger, and the radiated refrigerant is decompressed by the indoor expansion valve. Dehumidifying heating mode and dehumidifying cooling mode that absorb heat in the heat exchanger, and cooling mode in which the refrigerant discharged from the compressor is dissipated in the outdoor heat exchanger, the radiated refrigerant is decompressed by the indoor expansion valve, and then heat is absorbed in the heat exchanger. Those that switch and execute are being developed.

In this case, an accumulator is provided on the refrigerant suction side of the compressor. In the heating mode, the cooling electromagnetic valve is closed, the heating electromagnetic valve is opened, and the refrigerant discharged from the outdoor heat exchanger is allowed to flow through the accumulator, for example, cooling. In the mode, the heating electromagnetic valve is closed, the cooling electromagnetic valve is opened, the refrigerant discharged from the outdoor heat exchanger flows to the indoor expansion valve, and the refrigerant passed through the heat absorber flows to the accumulator. Then, in this accumulator, gas and liquid are separated once the refrigerant is stored, and the gas refrigerant is sucked into the compressor to prevent or suppress the liquid return to the compressor. (For example, see Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-94671

Here, in the accumulator when the compressor is stopped, the refrigerant and oil that have flowed out of the compressor and flowed through the refrigerant circuit flow in, and the liquid part of them collects in the accumulator and has a light specific gravity. The oil forms a layer on top of the liquid refrigerant and is in a stable state as if it were covered. In particular, in the heating mode, which is to be executed in an environment where the outside air temperature is low, the amount of liquid refrigerant and oil that exits the outdoor heat exchanger, passes through the solenoid valve for heating, flows into the accumulator, and accumulates inside the accumulator is large. Therefore, the oil level (the liquid level in the accumulator) rises to near the outlet of the accumulator.

When the compressor is started in the heating mode in such a state, or when it is switched from another operation mode (the above dehumidifying heating mode, dehumidifying cooling mode, cooling mode) to the heating mode, the compressor sucks in the refrigerant. The pressure in the accumulator will drop sharply. When the pressure in the accumulator drops sharply in this way, the refrigerant below the oil boils and vaporizes at once, causing a phenomenon called bumping that violently breaks through the layer of oil above.

When this bumping becomes severe, a large amount of liquid refrigerant in the accumulator is pushed out from the outlet, so that excessive liquid return to the compressor occurs, and the reliability of the compressor is impaired by liquid compression. become. In addition, since the bumping phenomenon in the accumulator is accompanied by a relatively loud noise, there is also a problem that the comfort of the passenger is impaired by the generation of noise.

The present invention has been made to solve the above-mentioned conventional technical problems, and when the compressor is started in the operation mode in which the refrigerant is depressurized by the outdoor expansion valve, or the operation in which the refrigerant is depressurized by the indoor expansion valve. It is an object of the present invention to provide a vehicle air conditioner capable of preventing or suppressing liquid return to the compressor and generation of noise in the accumulator that occur when switching from the mode to the operation mode in which the pressure is reduced by the outdoor expansion valve.

The vehicle air conditioner according to the first aspect of the present invention includes a compressor that compresses the refrigerant, an air flow passage through which the air supplied into the vehicle interior flows, and air that dissipates the refrigerant and supplies the air into the vehicle interior from the air flow passage. A radiator for heating, a heat exchanger for absorbing the refrigerant and cooling the air supplied to the passenger compartment from the air flow passage, an outdoor heat exchanger provided outside the passenger compartment, and the radiator. An outdoor expansion valve for reducing the pressure of the refrigerant flowing into the outdoor heat exchanger, an indoor expansion valve for reducing the pressure of the refrigerant flowing into the heat exchanger, an accumulator connected to the refrigerant suction side of the compressor, a radiator and To bypass the outdoor expansion valve and allow the refrigerant discharged from the compressor to flow directly into the outdoor heat exchanger, and to allow the refrigerant discharged from the outdoor heat exchanger to flow through the indoor expansion valve to the heat exchanger. The first on-off valve, the second on-off valve for flowing the refrigerant discharged from the outdoor heat exchanger to the accumulator without passing through the heat exchanger, and the refrigerant discharged from the compressor to flow to the radiator. A third on-off valve, a fourth on-off valve for flowing the refrigerant discharged from the compressor to the bypass pipe, an auxiliary heating device for heating the air supplied to the passenger compartment from the air flow passage, and a control device. By closing the first on-off valve and opening the second on-off valve by this control device, the refrigerant discharged from the compressor is radiated by the radiator, and the radiated refrigerant is dissipated by the outdoor expansion valve. After depressurizing, heat is absorbed by the outdoor heat exchanger, the refrigerant discharged from this outdoor heat exchanger flows through the accumulator, and the first operation mode and the first on-off valve are opened so that the accumulator sucks the heat into the compressor. By closing the second on-off valve, the refrigerant discharged from the outdoor heat exchanger is decompressed by the indoor expansion valve, then heat is absorbed by the heat absorber, and the refrigerant discharged from this heat exchanger flows through the accumulator and compressed from this accumulator. The second operation mode to be sucked into the machine is switched and executed. The first operation mode is the heating mode. In this heating mode, the third on-off valve is opened and the fourth on-off valve is closed. At the same time, in the second operation mode, the third on-off valve and the outdoor expansion valve are closed, and the fourth on-off valve is opened so that the refrigerant discharged from the compressor flows from the bypass pipe to the outdoor heat exchanger to dissipate heat. After decompressing the radiated refrigerant with the indoor expansion valve, heat is absorbed by the heat exchanger and the auxiliary heating device is heated, and the third on-off valve is opened and the fourth on-off valve is closed. Allows the refrigerant discharged from the compressor to flow from the radiator to the outdoor heat exchanger to exchange heat between the radiator and the outdoor heat exchanger. The compressor dissipates heat with a container, decompresses the radiated refrigerant with an indoor expansion valve, and then absorbs heat with a heat absorber in a dehumidifying / cooling mode, and by opening the third on-off valve and closing the fourth on-off valve. A cooling mode in which the refrigerant discharged from the radiator is passed from the radiator to the outdoor heat exchanger to dissipate heat in the outdoor heat exchanger, the radiated refrigerant is depressurized by the indoor expansion valve, and then heat is absorbed by the heat exchanger. By closing the on-off valve of No. 3 and the outdoor expansion valve and opening the fourth on-off valve, the refrigerant discharged from the compressor flows from the bypass pipe to the outdoor heat exchanger to dissipate heat, and the radiated refrigerant is dissipated to the indoor expansion valve. When the compressor is started from the first operation mode, it is one of the maximum cooling modes, or a combination thereof, or all of them, in which the compressor is depressurized and then absorbed by the heat exchanger. It is characterized in that the valve opening degree of the outdoor expansion valve is maintained at a predetermined large value for a predetermined period after the start-up.

The vehicle air conditioner according to the second aspect of the present invention includes a compressor that compresses the refrigerant, an air flow passage through which the air supplied into the vehicle interior flows, and air that dissipates the refrigerant and supplies the air into the vehicle interior from the air flow passage. A radiator for heating, a heat exchanger for absorbing the refrigerant and cooling the air supplied to the passenger compartment from the air flow passage, an outdoor heat exchanger provided outside the passenger compartment, and the radiator. An outdoor expansion valve for reducing the pressure of the refrigerant flowing into the outdoor heat exchanger, an indoor expansion valve for reducing the pressure of the refrigerant flowing into the heat exchanger, an accumulator connected to the refrigerant suction side of the compressor, a radiator and To bypass the outdoor expansion valve and allow the refrigerant discharged from the compressor to flow directly into the outdoor heat exchanger, and to allow the refrigerant discharged from the outdoor heat exchanger to flow through the indoor expansion valve to the heat exchanger. The first on-off valve, the second on-off valve for flowing the refrigerant discharged from the outdoor heat exchanger to the accumulator without passing through the heat exchanger, and the refrigerant discharged from the compressor to flow to the radiator. A third on-off valve, a fourth on-off valve for flowing the refrigerant discharged from the compressor to the bypass pipe, an auxiliary heating device for heating the air supplied to the passenger compartment from the air flow passage, and a control device. By closing the first on-off valve and opening the second on-off valve by this control device, the refrigerant discharged from the compressor is radiated by the radiator, and the radiated refrigerant is dissipated by the outdoor expansion valve. After depressurizing, heat is absorbed by the outdoor heat exchanger, the refrigerant discharged from this outdoor heat exchanger flows through the accumulator, and the first operation mode and the first on-off valve are opened so that the accumulator sucks the heat into the compressor. By closing the second on-off valve, the refrigerant discharged from the outdoor heat exchanger is decompressed by the indoor expansion valve, then heat is absorbed by the heat absorber, and the refrigerant discharged from this heat exchanger flows through the accumulator and compressed from this accumulator. The second operation mode to be sucked into the machine is switched and executed. The first operation mode is the heating mode. In this heating mode, the third on-off valve is opened and the fourth on-off valve is closed. At the same time, in the second operation mode, the third on-off valve and the outdoor expansion valve are closed, and the fourth on-off valve is opened so that the refrigerant discharged from the compressor flows from the bypass pipe to the outdoor heat exchanger to dissipate heat. After decompressing the radiated refrigerant with the indoor expansion valve, heat is absorbed by the heat exchanger and the auxiliary heating device is heated, and the third on-off valve is opened and the fourth on-off valve is closed. Allows the refrigerant discharged from the compressor to flow from the radiator to the outdoor heat exchanger to exchange heat between the radiator and the outdoor heat exchanger. The compressor dissipates heat with a container, decompresses the radiated refrigerant with an indoor expansion valve, and then absorbs heat with a heat absorber in a dehumidifying / cooling mode, and by opening the third on-off valve and closing the fourth on-off valve. A cooling mode in which the refrigerant discharged from the radiator is passed from the radiator to the outdoor heat exchanger to dissipate heat in the outdoor heat exchanger, the radiated refrigerant is depressurized by the indoor expansion valve, and then heat is absorbed by the heat exchanger. By closing the on-off valve of No. 3 and the outdoor expansion valve and opening the fourth on-off valve, the refrigerant discharged from the compressor flows from the bypass pipe to the outdoor heat exchanger to dissipate heat, and the radiated refrigerant is dissipated to the indoor expansion valve. The control device changes from the second operation mode to the first operation mode, which is one of the maximum cooling modes in which the heat is absorbed by the heat exchanger after depressurizing with, or a combination thereof, or all of them. At the time of transition, the valve opening degree of the outdoor expansion valve is maintained at a predetermined large value for a predetermined period after the transition.

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 interior flows, and the air supplied from the air flow passage to the vehicle interior by dissipating the refrigerant are heated. Heat exchanger for cooling the air supplied to the passenger compartment from the air flow passage by absorbing the refrigerant, the outdoor heat exchanger provided outside the passenger compartment, and the outdoor heat exchanger leaving the radiator. An outdoor expansion valve for reducing the pressure of the refrigerant flowing into the heat exchanger, an indoor expansion valve for reducing the pressure of the refrigerant flowing into the heat exchanger, an accumulator connected to the refrigerant suction side of the compressor, a radiator and an outdoor expansion valve. A bypass pipe for bypassing and allowing the refrigerant discharged from the compressor to flow directly into the outdoor heat exchanger, and a first for flowing the refrigerant discharged from the outdoor heat exchanger to the heat exchanger via the indoor expansion valve. An on-off valve, a second on-off valve for flowing the refrigerant discharged from the outdoor heat exchanger to the accumulator without passing through the heat exchanger, and a third on-off valve for flowing the refrigerant discharged from the compressor to the radiator. It is equipped with a valve, a fourth on-off valve for flowing the refrigerant discharged from the compressor to the bypass pipe, an auxiliary heating device for heating the air supplied to the passenger compartment from the air flow passage, and a control device. By closing the first on-off valve and opening the second on-off valve by the control device, the refrigerant discharged from the compressor is radiated by the radiator, and the radiated refrigerant is depressurized by the outdoor expansion valve. The first operation mode in which heat is absorbed by the outdoor heat exchanger, the refrigerant discharged from this outdoor heat exchanger flows to the accumulator, and the compressor is sucked from this accumulator, and the first on-off valve is opened to open and close the second. By closing the valve, the refrigerant discharged from the outdoor heat exchanger is decompressed by the indoor expansion valve, then heat is absorbed by the heat absorber, the refrigerant discharged from this heat exchanger flows into the accumulator, and is sucked into the compressor from this accumulator. In the vehicle air conditioner that switches and executes the second operation mode, when the control device activates the compressor from the above-mentioned heating mode, which is the first operation mode, the outdoor expansion valve of the outdoor expansion valve is activated for a predetermined period after the activation. Since the valve opening is maintained at a predetermined large value, it is possible to prevent the refrigerant in the accumulator from suddenly decreasing when the compressor is started.

As a result, it is possible to prevent a sudden drop in the pressure inside the accumulator when the compressor is started, so that sudden boiling occurs when the pressure inside the accumulator drops while the oil covers the liquid refrigerant. It has become possible to prevent or suppress the generation of air conditioners, effectively eliminate or suppress the generation of liquid compression in the compressor and the generation of noise in the accumulator, improve the reliability of the air conditioner for vehicles, and board the vehicle. The comfort of the person can also be effectively improved.

According to the invention of claim 2, in order to heat the compressor for compressing the refrigerant, the air flow passage through which the air supplied to the vehicle interior flows, and the air supplied from the air flow passage to the vehicle interior by dissipating the refrigerant. Heat exchanger for cooling the air supplied to the passenger compartment from the air flow passage by absorbing the refrigerant, the outdoor heat exchanger provided outside the passenger compartment, and the outdoor heat exchanger leaving the radiator. An outdoor expansion valve for reducing the pressure of the refrigerant flowing into the heat exchanger, an indoor expansion valve for reducing the pressure of the refrigerant flowing into the heat exchanger, an accumulator connected to the refrigerant suction side of the compressor, a radiator and an outdoor expansion valve. A bypass pipe for bypassing and allowing the refrigerant discharged from the compressor to flow directly into the outdoor heat exchanger, and a first for flowing the refrigerant discharged from the outdoor heat exchanger to the heat exchanger via the indoor expansion valve. An on-off valve, a second on-off valve for flowing the refrigerant discharged from the outdoor heat exchanger to the accumulator without passing through the heat exchanger, and a third on-off valve for flowing the refrigerant discharged from the compressor to the radiator. It is equipped with a valve, a fourth on-off valve for flowing the refrigerant discharged from the compressor to the bypass pipe, an auxiliary heating device for heating the air supplied to the passenger compartment from the air flow passage, and a control device. By closing the first on-off valve and opening the second on-off valve by the control device, the refrigerant discharged from the compressor is radiated by the radiator, and the radiated refrigerant is depressurized by the outdoor expansion valve. The first operation mode in which heat is absorbed by the outdoor heat exchanger, the refrigerant discharged from this outdoor heat exchanger flows into the accumulator, and the refrigerant is sucked into the compressor from this accumulator, and the first on-off valve is opened to open and close the second. By closing the valve, the refrigerant discharged from the outdoor heat exchanger is decompressed by the indoor expansion valve, then heat is absorbed by the heat absorber, the refrigerant discharged from this heat exchanger flows into the accumulator, and is sucked into the compressor from this accumulator. In the vehicle air conditioner that switches and executes the second operation mode, when the control device shifts from the second operation mode to the first operation mode, the valve opening degree of the outdoor expansion valve is set for a predetermined period after the shift. Is maintained at a predetermined large value, so that the second operation mode, the above-mentioned dehumidification / heating mode, the dehumidification / cooling mode, the cooling mode, or the maximum cooling mode to the first operation mode, the above-mentioned heating mode. During the transition to, the sudden decrease in the refrigerant in the accumulator is suppressed.

As a result, it is possible to prevent a sudden drop in the pressure inside the accumulator at the time of transition from the second operation mode to the first operation mode, so that the accumulator is in a state where the oil covers the liquid refrigerant. It has become possible to prevent or suppress the occurrence of sudden boiling that occurs when the internal pressure drops, and to effectively eliminate or suppress the generation of liquid compression in the compressor and noise in the accumulator, and vehicle air. The reliability of the accumulator can be improved and the comfort of the occupant can be effectively improved.

It is a block diagram of the air conditioner for a vehicle of one Embodiment to which this invention was applied (heating mode, dehumidifying heating mode, dehumidifying cooling mode and cooling mode). It is a block diagram of the electric circuit of the controller of the air conditioner for a vehicle of FIG. It is a block diagram in the MAX cooling mode (maximum cooling mode) of the air conditioner for a vehicle of FIG. It is a timing chart of each device explaining an example of bumping prevention control executed by the controller of FIG. 2 when a compressor is started in a heating mode. It is a timing chart of each device explaining an example of bumping prevention control executed by the controller of FIG. 2 when shifting from a dehumidifying heating mode to a 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 an air conditioner 1 for a vehicle according to an embodiment of the present invention. The vehicle of the embodiment to which the present invention is applied is an electric vehicle (EV) in which an engine (internal combustion engine) is not mounted, and travels by driving an electric motor for traveling with electric power charged in a battery. Yes (neither is shown), and the vehicle air conditioner 1 of the present invention is also driven by the power of the battery. That is, the vehicle air conditioner 1 of the embodiment performs the heating mode by the heat pump operation using the refrigerant circuit in the electric vehicle that cannot be heated by the waste heat of the engine, and further, the dehumidifying heating mode, the dehumidifying cooling mode, the cooling mode, Each operation mode of the MAX cooling mode (maximum cooling mode) is selectively executed.

It should be noted that the present invention is effective not only for electric vehicles as vehicles but also for so-called hybrid vehicles that use an engine and an electric motor for traveling, and further, it can be applied to ordinary vehicles traveling with an engine. Needless to say. The heating mode is the first operation mode in the present invention, the dehumidification heating mode, the dehumidification cooling mode, the cooling mode, and the MAX cooling mode is the second operation mode in the present invention.

The vehicle air conditioner 1 of the embodiment air-conditions (heating, cooling, dehumidifying, and ventilating) the interior of the electric vehicle, and includes an electric compressor 2 that compresses the refrigerant and the interior air of the vehicle. The radiator 4 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 and dissipates this refrigerant into the vehicle interior. An outdoor expansion valve 6 composed of an electric valve that decompresses and expands the refrigerant during heating, and a heat exchange between the refrigerant and the outside air so as to be provided outside the vehicle interior and function as a radiator during cooling and as an evaporator during heating. An indoor expansion valve 8 composed of an outdoor heat exchanger 7 for reducing the pressure and expansion of the refrigerant, and a heat absorber 9 provided in the air flow passage 3 for absorbing heat from the inside and outside of the vehicle during cooling and dehumidification. And the accumulator 12 and the like are sequentially connected by the refrigerant pipe 13, and the refrigerant circuit R is configured.

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 forcibly ventilates the outdoor air to the outdoor heat exchanger 7 to exchange heat between the outside air and the refrigerant, whereby the outdoor air is outdoors even when the vehicle is stopped (that is, the vehicle speed is 0 km / h). The heat exchanger 7 is configured to ventilate outside air.

Further, the outdoor heat exchanger 7 has a receiver dryer portion 14 and a supercooling portion 16 in sequence on the downstream side of the refrigerant, and the refrigerant pipe 13A discharged from the outdoor heat exchanger 7 is an electromagnetic valve 17 (first) that is opened during cooling. The on-off valve) is connected to the receiver dryer unit 14, and the refrigerant pipe 13B on the outlet side of the supercooling unit 16 is connected to the inlet side of the heat exchanger 9 via the indoor expansion valve 8. The receiver dryer section 14 and the supercooling section 16 structurally form a part of the outdoor heat exchanger 7.

Further, the refrigerant pipe 13B between the supercooling unit 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 of them constitute the internal heat exchanger 19. As a result, the refrigerant flowing into the indoor expansion valve 8 via the refrigerant pipe 13B is configured to be cooled (supercooled) by the low-temperature refrigerant leaving the heat absorber 9.

Further, the refrigerant pipe 13A coming out of the outdoor heat exchanger 7 is branched into the refrigerant pipe 13D, and the branched refrigerant pipe 13D is inside via an electromagnetic valve 21 (second on-off valve) opened during heating. It is communicatively connected to the refrigerant pipe 13C on the downstream side of the heat exchanger 19. The refrigerant pipe 13C is connected to the accumulator 12, and the accumulator 12 is connected to the refrigerant suction side of the compressor 2. Further, the refrigerant pipe 13E on the outlet side of the radiator 4 is connected to the inlet side of the outdoor heat exchanger 7 via the outdoor expansion valve 6.

Further, the refrigerant pipe 13G between the discharge side of the compressor 2 and the inlet side of the radiator 4 is provided with a solenoid valve 30 (third on-off valve) that is closed during dehumidifying and heating and MAX cooling, which will be described later. In this case, the refrigerant pipe 13G branches to the bypass pipe 35 on the upstream side of the solenoid valve 30, and the bypass pipe 35 is passed through the solenoid valve 40 (fourth on-off valve) that is opened during dehumidifying heating and MAX cooling. It is communicated with the refrigerant pipe 13E on the downstream side of the outdoor expansion valve 6. The bypass device 45 is composed of the bypass pipe 35, the solenoid valve 30, and the solenoid valve 40.

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

Further, in the air flow passage 3 on the air upstream side of the heat absorber 9, each suction port of the outside air suction port and the inside air suction port is formed (represented by the suction port 25 in FIG. 1), and this suction port is formed. The suction switching damper 26 for switching the air introduced into the air flow passage 3 into 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, is provided. 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 and outside air to the air flow passage 3 is provided.

Further, in FIG. 1, 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 which is on the air upstream side of the radiator 4 with respect to the air flow of the air flow passage 3. There is. Then, 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 serves as a so-called heater core, which heats or complements the interior of the vehicle.

Further, in the air flow passage 3 on the air upstream side of the auxiliary heater 23, the air (inside air or outside air) in the air flow passage 3 after flowing into the air flow passage 3 and passing through the heat absorber 9 is assisted. An air mix damper 28 for adjusting the ratio of ventilation to the heater 23 and the radiator 4 is provided. Further, FOOT (foot), VENT (vent), and DEF (diff) outlets (represented by outlet 29 in FIG. 1) are formed in the air flow passage 3 on the air downstream side of the radiator 4. The outlet 29 is provided with an outlet switching damper 31 for switching and controlling the blowing of air from each of the 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 provided with a processor, and the outside air 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 air) in the vehicle interior. The inside air temperature sensor 37 that detects the temperature, the inside air humidity sensor 38 that detects the humidity of the air inside the vehicle, the indoor CO ₂ concentration sensor 39 that detects the carbon dioxide concentration inside the vehicle, and the air outlet 29 blows into the vehicle interior. A blowout temperature sensor 41 that detects the temperature of the air to be generated, a discharge pressure sensor 42 that detects the discharge refrigerant pressure (discharge pressure Pd) of the compressor 2, and a discharge temperature sensor 43 that detects the discharge refrigerant temperature of the compressor 2. , The suction pressure sensor 44 that detects the suction refrigerant pressure of the compressor 2, the suction temperature sensor 55 that detects the suction refrigerant temperature of the compressor 2, and the temperature of the radiator 4 (the temperature of the air that has passed through the radiator 4 or the temperature of the air that has passed through the radiator 4). The radiator temperature sensor 46 that detects the temperature of the radiator 4 itself: the radiator temperature TH) and the refrigerant pressure of the radiator 4 (the pressure of the refrigerant in the radiator 4 or immediately after leaving the radiator 4: radiator A radiator pressure sensor 47 that detects the pressure PCI) and a heat absorber temperature sensor 48 that detects the temperature of the heat absorber 9 (the temperature of the air that has passed through the heat absorber 9 or the temperature of the heat absorber 9 itself: the heat absorber temperature Te). And, for example, a heat absorber pressure sensor 49 for detecting the refrigerant pressure of the heat absorber 9 (the pressure of the refrigerant in the heat absorber 9 or immediately after leaving the heat absorber 9), and for example, for detecting the amount of solar radiation into the vehicle interior. A photosensor 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 an operation mode, and outdoor heat exchange. An outdoor heat exchanger temperature sensor 54 that detects the temperature of the vessel 7 (the temperature of the refrigerant immediately after exiting the outdoor heat exchanger 7 or the temperature of the outdoor heat exchanger 7 itself: the outdoor heat exchanger temperature TXO), and the outdoor Each of the outdoor heat exchanger pressure sensors 56 that detects the refrigerant pressure of the heat exchanger 7 (the pressure of the refrigerant inside the outdoor heat exchanger 7 or immediately after coming out of the outdoor heat exchanger 7: outdoor heat exchanger pressure PXO). The output is connected. Further, at the input of the controller 32, an auxiliary heater temperature sensor that detects 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). Fifty outputs are also connected.

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

With the above configuration, the operation of the vehicle air conditioner 1 of the embodiment will be described next. In the embodiment, the controller 32 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 (maximum cooling mode). First, the outline of the flow and control of the refrigerant in each operation mode will be described.

(1) Heating mode (first operation mode)
When the heating mode is selected by the controller 32 (auto mode) or by the manual operation (manual mode) to the air conditioning operation unit 53, the controller 32 opens the solenoid valve 21 (second on-off valve) for heating to cool the air. The solenoid valve 17 (first on-off valve) for use is closed. Further, the solenoid valve 30 for reheating is opened, and the solenoid valve 40 for bypass is closed.

Then, the compressor 2 and the blowers 15 and 27 are operated, and the air mix damper 28 is blown out from the indoor blower 27 and passed through the heat absorber 9 in the air flow passage 3 as shown by the broken line in FIG. The air is ventilated to 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 from the refrigerant pipe 13G via the solenoid valve 30. Since the air in the air flow passage 3 is ventilated through the radiator 4, the air in the air flow passage 3 is the high temperature refrigerant in the radiator 4 (when the auxiliary heater 23 operates, the auxiliary heater 23 and the radiator 4 are used. ), On the other hand, the refrigerant in the radiator 4 is deprived of heat by air and cooled to be condensed.

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 draws heat from the outside air that is ventilated by the outdoor blower 15 or by running. That is, the refrigerant circuit R serves as a heat pump. Then, the low-temperature refrigerant that has exited the outdoor heat exchanger 7 enters the accumulator 12 from the refrigerant pipe 13C via the refrigerant pipe 13A, the electromagnetic valve 21, and the refrigerant pipe 13D, and after gas-liquid separation there, the gas refrigerant is used in the compressor 2. Repeat the circulation sucked into. That is, the refrigerant discharged from the outdoor heat exchanger 7 flows to the accumulator 12 without passing through the heat absorber 9. Then, 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. Become.

The controller 32 calculates the target radiator pressure PCO (target value of the radiator pressure PCI) from the target radiator temperature TCO (target value of the radiator temperature TH) calculated from the target blowout temperature TAO described later, and this target heat dissipation. The rotation speed of the compressor 2 is controlled based on the vessel 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 determines 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. It controls and controls the degree of supercooling SC of the refrigerant at the outlet of the radiator 4. The target radiator temperature TCO is basically TCO = TAO, but a predetermined control limit is provided.

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

Here, if the auxiliary heater 23 is arranged on the downstream side of the air 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. Since the temperature is increased by 4, the resistance value of the PTC heater becomes large, the current value also becomes low, and the calorific value decreases. However, by arranging the auxiliary heater 23 on the air upstream side of the radiator 4, the example of the embodiment As described above, the ability of the auxiliary heater 23 composed of the PTC heater can be fully exhibited.

(2) Dehumidifying and heating mode (second operation mode)
Next, in the dehumidifying / 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 the blowers 15 and 27 are operated, and the air mix damper 28 is blown out from the indoor blower 27 and passed through the heat absorber 9 in the air flow passage 3 as shown by the broken line in FIG. The air is ventilated to the auxiliary heater 23 and the radiator 4.

As a result, the high-temperature and 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 flows into the refrigerant pipe on the downstream side of the outdoor expansion valve 6. It will reach 13E. At this time, since the outdoor expansion valve 6 is fully closed, the refrigerant flows into the outdoor heat exchanger 7. The refrigerant flowing into the outdoor heat exchanger 7 is air-cooled and condensed by traveling there or by the outside air ventilated by the outdoor blower 15. The refrigerant exiting the outdoor heat exchanger 7 flows sequentially from the refrigerant pipe 13A through the solenoid valve 17 to the receiver dryer section 14 and the supercooling section 16. Here the refrigerant is supercooled.

The refrigerant exiting 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. After the refrigerant is depressurized by the indoor expansion valve 8, it flows into the heat absorber 9 and evaporates. The air blown out from the indoor blower 27 is cooled by the heat absorption action at this time, and the moisture in the air condenses and adheres to the heat absorber 9, so that the air in the air flow passage 3 is cooled and It is dehumidified. The refrigerant evaporated in the heat absorber 9 passes through the internal heat exchanger 19 and reaches the accumulator 12 via the refrigerant pipe 13C, and is repeatedly sucked into the compressor 2 through the accumulator 12.

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

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

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

Since the auxiliary heater 23 is arranged on the upstream side of the air of the radiator 4, the air heated by the auxiliary heater 23 passes through the radiator 4, but in this dehumidifying and heating mode, the refrigerant is sent to the radiator 4. Since the heat is not washed away, the inconvenience that the radiator 4 absorbs heat from the air heated by the auxiliary heater 23 is also eliminated. That is, it is suppressed that the temperature of the air blown into the vehicle interior is lowered by the radiator 4, and the COP is also improved.

(3) Dehumidifying and cooling mode (second operation mode)
Next, in the dehumidifying / 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 the blowers 15 and 27 are operated, and the air mix damper 28 is blown out from the indoor blower 27 and passed through the heat absorber 9 in the air flow passage 3 as shown by the broken line in FIG. The air is ventilated to 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 from the refrigerant pipe 13G via the solenoid valve 30. Since the air in the air flow passage 3 is ventilated through the radiator 4, the air in the air flow passage 3 is heated by the high temperature refrigerant in the radiator 4, while the refrigerant in the radiator 4 heats the air. It is deprived, cooled, and condensed.

The refrigerant leaving the radiator 4 reaches the outdoor expansion valve 6 via the refrigerant pipe 13E, and flows into the outdoor heat exchanger 7 via the outdoor expansion valve 6 which is slightly opened and controlled. The refrigerant flowing into the outdoor heat exchanger 7 is air-cooled and condensed by traveling there or by the outside air ventilated by the outdoor blower 15. The refrigerant exiting the outdoor heat exchanger 7 flows sequentially from the refrigerant pipe 13A through the solenoid valve 17 to the receiver dryer section 14 and the supercooling section 16. Here the refrigerant is supercooled.

The refrigerant exiting 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. After the refrigerant is depressurized by the indoor expansion valve 8, it flows into the heat absorber 9 and evaporates. Due to the endothermic action at this time, the moisture in the air blown out from the indoor blower 27 condenses and adheres to the heat absorber 9, so that the air is cooled and dehumidified.

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

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 outdoor expansion valve based on the high pressure of the refrigerant circuit R described above. The valve opening degree of No. 6 is controlled, and the refrigerant pressure (radiator pressure PCI) of the radiator 4 is controlled.

(4) Cooling mode (second operation 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 cooling mode. The controller 32 controls the air mix damper 28, and as shown by the solid line in FIG. 1, the air in the air flow passage 3 after being blown out from the indoor blower 27 and passing through the heat absorber 9 dissipates heat to the auxiliary heater 23. Adjust the ratio of ventilation to the vessel 4. Further, the controller 32 does not energize the auxiliary heater 23.

As a result, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the radiator 4 from the refrigerant pipe 13G via the solenoid valve 30, and the refrigerant discharged from the radiator 4 passes through the refrigerant pipe 13E and the outdoor expansion valve 6 To reach. 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 running or by the outside air ventilated by the outdoor blower 15 and condensed. Liquefaction. The refrigerant exiting the outdoor heat exchanger 7 flows sequentially from the refrigerant pipe 13A through the solenoid valve 17 to the receiver dryer section 14 and the supercooling section 16. Here the refrigerant is supercooled.

The refrigerant exiting 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. After the refrigerant is depressurized by the indoor expansion valve 8, it flows into the heat absorber 9 and evaporates. The air blown out from the indoor blower 27 is cooled by the endothermic action at this time. Further, the moisture in the air condenses and adheres to the heat absorber 9.

The refrigerant evaporated in the heat absorber 9 passes through the internal heat exchanger 19 and reaches the accumulator 12 via the refrigerant pipe 13C, and is repeatedly sucked into the compressor 2 through the accumulator 12. Since the dehumidified air cooled by the heat absorber 9 is blown out 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 by this. become. Further, in this 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 the target value thereof. To control.

(5) MAX cooling mode (maximum cooling mode: second operation 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 the blowers 15 and 27 are operated, and the air mix damper 28 is in a state where the air in the air flow passage 3 is not ventilated to the auxiliary heater 23 and the radiator 4 as shown in FIG. However, there is no problem even if there is some ventilation. Further, the controller 32 does not energize the auxiliary heater 23.

As a result, the high-temperature and 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 flows into the refrigerant pipe on the downstream side of the outdoor expansion valve 6. It will reach 13E. At this time, since the outdoor expansion valve 6 is fully closed, the refrigerant flows into the outdoor heat exchanger 7. The refrigerant flowing into the outdoor heat exchanger 7 is air-cooled and condensed by traveling there or by the outside air ventilated by the outdoor blower 15. The refrigerant exiting the outdoor heat exchanger 7 flows sequentially from the refrigerant pipe 13A through the solenoid valve 17 to the receiver dryer section 14 and the supercooling section 16. Here the refrigerant is supercooled.

The refrigerant exiting 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. After the refrigerant is depressurized by the indoor expansion valve 8, it flows into the heat absorber 9 and evaporates. The air blown out from the indoor blower 27 is cooled by the endothermic action at this time. Further, since the moisture in the air condenses and adheres to the heat absorber 9, the air in the air flow passage 3 is dehumidified. The refrigerant evaporated in the heat absorber 9 passes through the internal heat exchanger 19 and reaches the accumulator 12 via the refrigerant pipe 13C, and is repeatedly sucked into the compressor 2 through the accumulator 12. At this time, since the outdoor expansion valve 6 is fully closed, it is possible to suppress or prevent the inconvenience that the refrigerant discharged from the compressor 2 flows back from the outdoor expansion valve 6 into the radiator 4. .. As a result, it becomes possible to suppress or eliminate the decrease in the amount of refrigerant circulation and secure the air conditioning capacity.

Here, since the high-temperature refrigerant is flowing through the radiator 4 in the above-mentioned cooling mode, direct heat conduction from the radiator 4 to the HVAC unit 10 is not a little generated, but in this MAX cooling mode, the refrigerant is transferred to the radiator 4. Does not flow, so that 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, the vehicle interior is strongly cooled, and particularly in an environment where the outside air temperature Tam is high, the vehicle interior can be quickly cooled and comfortable vehicle interior air conditioning can be realized. Further, even 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 the target value thereof. 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 of the above operation modes (adjusted by the air mix damper 28). ), And it is blown into the passenger compartment from the outlet 29. The controller 32 is set by the air conditioning operation unit 53 with the outside air temperature Tam detected by the outside air temperature sensor 33, the temperature inside the vehicle body 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 vehicle interior temperature (set temperature) in the vehicle interior, and each operation mode is 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 has the outside air temperature Tam, the humidity in the vehicle interior, the target blowout temperature TAO, the radiator temperature TH, the target radiator temperature TCO, the heat absorber temperature Te, the target heat absorber temperature TEO, and the presence or absence of a dehumidification request in the vehicle interior. Based on the parameters such as, heating mode to dehumidifying heating mode, dehumidifying heating mode to dehumidifying cooling mode, dehumidifying cooling mode to cooling mode, cooling mode to MAX cooling mode, this MAX cooling mode to cooling mode, cooling mode to dehumidifying cooling mode , Switch the operation mode from dehumidifying / cooling mode to dehumidifying / heating mode and from dehumidifying / heating mode to heating mode. In addition, the heating mode may be switched to the dehumidifying / cooling mode or the cooling mode, and the dehumidifying / cooling mode or the cooling mode may be switched to the heating mode. In the embodiment, by switching each operation mode as described above, the heating mode, the dehumidifying heating mode, the dehumidifying cooling mode, the cooling mode, and the MAX cooling mode can be accurately switched according to the environmental conditions and the necessity of dehumidification. Moreover, efficient vehicle interior air conditioning is realized.

(7) Refrigerant scavenging operation As described above, in the dehumidifying and heating mode, the electromagnetic valve 30 is closed and the outdoor expansion valve 6 is also fully closed so that the refrigerant does not flow to the radiator 4, so the heating mode is changed to the dehumidifying and heating mode. At the time of switching, the refrigerant remaining in the radiator 4 falls asleep inside, and the amount of circulating refrigerant decreases.

Therefore, in the embodiment, the controller 32 executes the refrigerant scavenging operation when switching from the heating mode to the dehumidifying heating mode. In this refrigerant scavenging operation, when switching from the heating mode to the dehumidifying / heating mode, the controller 32 closes the solenoid valve 21, opens the solenoid valve 17, shifts to the dehumidifying / heating mode, and then switches between the solenoid valve 30 and the solenoid valve 40. Before, the valve opening degree of the outdoor expansion valve 6 is expanded (for example, fully opened) by a predetermined time. This state is the same as the cooling mode. Further, in the embodiment, the rotation speed NC of the compressor 2 is maintained low (for example, the minimum rotation speed in control).

As a result, the refrigerant existing between the solenoid valve 30 including the radiator 4 and the outdoor expansion valve 6 is expelled in the direction of the outdoor heat exchanger 7 (scavenging). Then, after the predetermined period has elapsed, the solenoid valve 30 is closed, the solenoid valve 40 is opened, and the outdoor expansion valve 6 is closed toward full closure. After the outdoor expansion valve 6 is fully closed, the controller 32 shifts to a state in which the rotation speed of the compressor 2 is controlled within the operating range in the dehumidifying / heating mode. By such a refrigerant scavenging operation, it is possible to prevent the refrigerant from falling into the radiator 4 and to secure the amount of refrigerant circulating in the refrigerant circuit R to prevent deterioration of the air conditioning performance.

(8) bumping prevention control Here, as described above, in the accumulator 12 when the compressor 2 is stopped, the refrigerant and oil that have flowed out of the compressor 2 and flowed through the refrigerant circuit R flow in, of which The liquid portion of the above is accumulated in the accumulator 12, and the oil having a light specific gravity forms a layer on the liquid refrigerant, and is in a stable state as if it were covered. In particular, in the heating mode, the amount of liquid refrigerant and oil that exits from the outdoor heat exchanger 7, passes through the solenoid valve 21, flows into the accumulator 12, and accumulates inside the accumulator 12 also increases.

When the compressor 2 is started in such a heating mode, the refrigerant in the accumulator 12 is sucked by the compressor 2, so that the pressure in the accumulator 12 drops sharply and the refrigerant below the oil boils at once. It evaporates and causes sudden boiling that violently breaks through the upper oil layer, causing excessive liquid return and noise (noise) to the compressor 2. In such sudden boiling, the refrigerant discharged from the outdoor heat exchanger 7 flows from the indoor expansion valve 8 toward the heat absorber 9 in a dehumidifying heating mode, a dehumidifying cooling mode, a cooling mode, and a MAX cooling mode (second operation mode). There is also a concern when shifting from the heating mode (first operation mode) to the heating mode (first operation mode). Therefore, when the controller 32 starts the compressor 2 in the heating mode, or when switching from the dehumidifying heating mode, the dehumidifying cooling mode, the cooling mode, and the MAX cooling mode to the heating mode, the controller 32 executes the sudden boiling prevention control described below.

(8-1) Crash prevention control when starting the compressor 2 in the heating mode First, referring to FIG. 4, starting the compressor 2 of the vehicle air conditioner 1 in the heating mode (first operation mode). An example of bumping prevention control executed by the controller 32 at the time of the operation will be described. The timing chart of FIG. 4 shows the rotation speed NC of the compressor 2 when the compressor 2 is started in the heating mode, the valve opening degree of the outdoor expansion valve 6, the state of the solenoid valve 17 and the solenoid valve 21, and the like. There is.

When the controller 32 starts the compressor 2 from the stopped state in the heating mode, the solenoid valve 17 is first closed, the solenoid valve 21 is opened, and then the valve of the outdoor expansion valve 6 (fully open while stopped). The opening degree is changed toward the predetermined valve opening degree PPS1. The valve opening PPS1 is a predetermined large valve opening that is slightly open. The auxiliary heater 23 starts controlling the operating range in the heating mode. Then, when the valve opening of the outdoor expansion valve 6 reaches the valve opening PPS1, the compressor 2 is started to shift to a control state (feedforward + feedback control) in the operating range in the heating mode. (Rotation speed NC converges to the target value).

The controller 32 keeps the valve opening degree of the outdoor expansion valve 6 fixed to PPS1 for a predetermined period (for example, 30 seconds) after the compressor 2 is started, and after the predetermined period elapses, the operating range in the heating mode. It shifts to the control state in. This predetermined period is the period of bumping prevention control. As described above, when the compressor 2 is started from the heating mode, the controller 32 maintains the valve opening degree of the outdoor expansion valve 6 at a predetermined large value PPS1 for a predetermined period after the start, so that the compressor 32 is compressed. It is suppressed that the refrigerant in the accumulator 12 suddenly decreases when the machine 2 is started.

As a result, it is possible to prevent a sudden drop in the pressure in the accumulator 12 when the compressor 2 is started, so that when the pressure in the accumulator 12 drops in a state where the oil covers the liquid refrigerant. It is possible to prevent or suppress the occurrence of sudden boiling that occurs in the compressor 2, and effectively eliminate or suppress the generation of liquid compression in the compressor 2 and noise in the accumulator 12. Further, by maintaining the valve opening degree of the outdoor expansion valve 6 at a predetermined valve opening degree PPS1 (a predetermined large value), the pressure change in the accumulator 12 accompanying the operation of the outdoor expansion valve 6 is also suppressed. As a result, the reliability of the vehicle air conditioner 1 can be improved, and the comfort of the occupant can be effectively improved.

(8-2) Crash prevention control when shifting from the dehumidifying / heating mode to the heating mode Next, referring to FIG. 5, the dehumidifying / heating mode (second operation mode) is changed to the heating mode (first operation mode). An example of bumping prevention control executed by the controller 32 at the time of transition will be described. The timing chart of FIG. 5 shows the rotation speed NC of the compressor 2 when shifting from the dehumidifying heating mode to the heating mode, the valve opening degree of the outdoor expansion valve 6, the solenoid valve 40, the solenoid valve 30, the solenoid valve 17, and the solenoid valve. The state of the valve 21 and the like are shown.

After shifting from the dehumidifying / heating mode to the heating mode, the controller 32 first stops the compressor 2 and opens the outdoor expansion valve 6, and sets the valve opening to the valve opening PPS1 which is a predetermined value of the opening slightly described above. We will continue to expand toward. Then, after the outdoor expansion valve 6 reaches the valve opening degree PPS1, the controller 32 closes the solenoid valve 40 and opens the solenoid valve 30. Next, the controller 32 starts the compressor 2, closes the solenoid valve 17, opens the solenoid valve 21, and shifts the compressor 2 to a control state (feedforward + feedback control) in the operating range in the heating mode. I will go.

The controller 32 fixes and maintains the valve opening degree of the outdoor expansion valve 6 to the PPS 1 for a predetermined period after the start of the compressor 2 (for example, 30 seconds described above), and after the elapse of the predetermined period, in the heating mode. It shifts to the control state in the operating range of. This predetermined period is the period of bumping prevention control. As described above, when the controller 32 shifts from the dehumidifying / heating mode (second operation mode) to the heating mode (first operation mode), the outdoor expansion valve 6 is similarly opened for a predetermined period after the shift. The degree is maintained at a predetermined valve opening PPS1 (a predetermined large value). As a result, the occurrence of bumping due to a sudden drop in pressure in the accumulator 12 is eliminated or suppressed as in the case of starting the compressor 2 in the heating mode described above, and comfortable air conditioning operation is realized.

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 the present invention is not limited thereto. The present invention is also effective when the heating mode and any of the other operation modes, or a combination thereof, are switched and executed. For example, the present invention may be executed when the mode is switched between the dehumidifying cooling mode and the mode for shifting from the cooling mode to the heating mode, and it is also effective when the mode can be directly shifted from the MAX cooling mode to the heating mode.

Further, the switching control of each operation mode shown in the embodiment is not limited to that, and the outside air temperature Tam, the humidity in the vehicle interior, the target blowout temperature TAO, depending on the capacity of the air conditioner for the vehicle and the usage environment. Adopt any of the parameters such as radiator temperature TH, target radiator temperature TCO, heat absorber temperature Te, target heat absorber temperature TEO, presence / absence of dehumidification requirement in the vehicle interior, or a combination thereof, or all of them. It is good to set appropriate conditions.

Further, the auxiliary heating device is not limited to the auxiliary heater 23 shown in the embodiment, but is a heat medium circulation circuit that circulates a heat medium heated by the heater to heat the air in the air flow passage, or an engine. A heater core or the like that circulates the heated radiator water may be used. Further, the configuration of the refrigerant circuit R described in each of the above embodiments is not limited to that, and it goes without saying that the configuration can be changed without departing from the spirit of the present invention.

1 Vehicle air conditioner 2 Compressor 3 Air flow passage 4 Heat sink 6 Outdoor expansion valve 7 Outdoor heat exchanger 8 Indoor expansion valve 9 Heat absorber 12 Accumulator 17 Solenoid valve (first on-off valve)
21 Solenoid valve (second on-off valve)
23 Auxiliary heater (auxiliary heating device)
27 Indoor blower (blower fan)
28 Air mix damper 30 Solenoid valve (third on-off valve)
40 Solenoid valve (fourth on-off valve)
32 controller (control device)
35 Bypass piping 45 Bypass device R Refrigerant circuit

Claims (2)

A compressor that compresses the refrigerant and
An air flow passage through which the air supplied to the passenger compartment flows, and
A radiator for radiating the refrigerant and heating the air supplied from the air flow passage to the passenger compartment,
A heat absorber for absorbing heat from the refrigerant and cooling the air supplied from the air flow passage to the vehicle interior.
An outdoor heat exchanger provided outside the vehicle interior and
An outdoor expansion valve for reducing the pressure of the refrigerant that leaves the radiator and flows into the outdoor heat exchanger.
An indoor expansion valve for reducing the pressure of the refrigerant flowing into the heat absorber,
An accumulator connected to the refrigerant suction side of the compressor,
Bypass piping for bypassing the radiator and the outdoor expansion valve and allowing the refrigerant discharged from the compressor to flow directly into the outdoor heat exchanger.
A first on-off valve for flowing the refrigerant discharged from the outdoor heat exchanger to the heat absorber via the indoor expansion valve, and
A second on-off valve for allowing the refrigerant discharged from the outdoor heat exchanger to flow to the accumulator without passing through the heat absorber.
A third on-off valve for flowing the refrigerant discharged from the compressor to the radiator, and
A fourth on-off valve for flowing the refrigerant discharged from the compressor into the bypass pipe, and
An auxiliary heating device for heating the air supplied from the air flow passage to the passenger compartment,
Equipped with a control device
By closing the first on-off valve and opening the second on-off valve by the control device, the refrigerant discharged from the compressor is radiated by the radiator, and the radiated refrigerant is expanded outdoors. A first operation mode in which the pressure is reduced by the valve, heat is absorbed by the outdoor heat exchanger, the refrigerant discharged from the outdoor heat exchanger is allowed to flow through the accumulator, and the refrigerant is sucked from the accumulator into the compressor.
By opening the first on-off valve and closing the second on-off valve, the refrigerant discharged from the outdoor heat exchanger is decompressed by the indoor expansion valve, and then heat is absorbed by the heat absorber. In a vehicle air conditioner that switches and executes a second operation mode in which the refrigerant discharged from the compressor is allowed to flow into the accumulator and is sucked into the compressor from the accumulator.
The first operation mode is a heating mode, in which the third on-off valve is opened, the fourth on-off valve is closed, and the fourth on-off valve is closed.
The second operation mode is
By closing the third on-off valve and the outdoor expansion valve and opening the fourth on-off valve, the refrigerant discharged from the compressor is allowed to flow from the bypass pipe to the outdoor heat exchanger to dissipate heat. A dehumidifying / heating mode in which the refrigerant is decompressed by the indoor expansion valve and then heat is absorbed by the heat exchanger and the auxiliary heating device is heated.
By opening the third on-off valve and closing the fourth on-off valve, the refrigerant discharged from the compressor flows from the radiator to the outdoor heat exchanger to the radiator and the outdoor heat exchanger. A dehumidifying / cooling mode in which the radiated refrigerant is decompressed by the indoor expansion valve and then heat is absorbed by the heat exchanger.
By opening the third on-off valve and closing the fourth on-off valve, the refrigerant discharged from the compressor flows from the radiator to the outdoor heat exchanger and is radiated by the outdoor heat exchanger. A cooling mode in which the radiated refrigerant is decompressed by the indoor expansion valve and then heat is absorbed by the heat exchanger.
By closing the third on-off valve and the outdoor expansion valve and opening the fourth on-off valve, the refrigerant discharged from the compressor is allowed to flow from the bypass pipe to the outdoor heat exchanger to dissipate heat. Any one of the maximum cooling modes in which the refrigerant is decompressed by the indoor expansion valve and then absorbed by the heat exchanger, a combination thereof, or all of them.
The control device is characterized in that when the compressor is started from the first operation mode, the valve opening degree of the outdoor expansion valve is maintained at a predetermined large value for a predetermined period after the start. Harmonizer. A compressor that compresses the refrigerant and
An air flow passage through which the air supplied to the passenger compartment flows, and
A radiator for radiating the refrigerant and heating the air supplied from the air flow passage to the passenger compartment,
A heat absorber for absorbing heat from the refrigerant and cooling the air supplied from the air flow passage to the vehicle interior.
An outdoor heat exchanger provided outside the vehicle interior and
An outdoor expansion valve for reducing the pressure of the refrigerant that leaves the radiator and flows into the outdoor heat exchanger.
An indoor expansion valve for reducing the pressure of the refrigerant flowing into the heat absorber,
An accumulator connected to the refrigerant suction side of the compressor,
Bypass piping for bypassing the radiator and the outdoor expansion valve and allowing the refrigerant discharged from the compressor to flow directly into the outdoor heat exchanger.
A first on-off valve for flowing the refrigerant discharged from the outdoor heat exchanger to the heat absorber via the indoor expansion valve, and
A second on-off valve for allowing the refrigerant discharged from the outdoor heat exchanger to flow to the accumulator without passing through the heat absorber.
A third on-off valve for flowing the refrigerant discharged from the compressor to the radiator, and
A fourth on-off valve for flowing the refrigerant discharged from the compressor into the bypass pipe, and
An auxiliary heating device for heating the air supplied from the air flow passage to the passenger compartment,
Equipped with a control device
By closing the first on-off valve and opening the second on-off valve by the control device, the refrigerant discharged from the compressor is radiated by the radiator, and the radiated refrigerant is expanded outdoors. A first operation mode in which the pressure is reduced by the valve, heat is absorbed by the outdoor heat exchanger, the refrigerant discharged from the outdoor heat exchanger is allowed to flow through the accumulator, and the refrigerant is sucked from the accumulator into the compressor.
By opening the first on-off valve and closing the second on-off valve, the refrigerant discharged from the outdoor heat exchanger is decompressed by the indoor expansion valve, and then heat is absorbed by the heat absorber. In a vehicle air conditioner that switches and executes a second operation mode in which the refrigerant discharged from the compressor is allowed to flow into the accumulator and is sucked into the compressor from the accumulator.
The first operation mode is a heating mode, in which the third on-off valve is opened, the fourth on-off valve is closed, and the fourth on-off valve is closed.
The second operation mode is
By closing the third on-off valve and the outdoor expansion valve and opening the fourth on-off valve, the refrigerant discharged from the compressor is allowed to flow from the bypass pipe to the outdoor heat exchanger to dissipate heat. A dehumidifying / heating mode in which the refrigerant is decompressed by the indoor expansion valve and then heat is absorbed by the heat exchanger and the auxiliary heating device is heated.
By opening the third on-off valve and closing the fourth on-off valve, the refrigerant discharged from the compressor flows from the radiator to the outdoor heat exchanger to the radiator and the outdoor heat exchanger. A dehumidifying / cooling mode in which the radiated refrigerant is decompressed by the indoor expansion valve and then heat is absorbed by the heat exchanger.
By opening the third on-off valve and closing the fourth on-off valve, the refrigerant discharged from the compressor flows from the radiator to the outdoor heat exchanger and is radiated by the outdoor heat exchanger. A cooling mode in which the radiated refrigerant is decompressed by the indoor expansion valve and then heat is absorbed by the heat exchanger.
By closing the third on-off valve and the outdoor expansion valve and opening the fourth on-off valve, the refrigerant discharged from the compressor is allowed to flow from the bypass pipe to the outdoor heat exchanger to dissipate heat. Any one of the maximum cooling modes in which the refrigerant is decompressed by the indoor expansion valve and then absorbed by the heat exchanger, a combination thereof, or all of them.
The control device is characterized in that when shifting from the second operation mode to the first operation mode, the valve opening degree of the outdoor expansion valve is maintained at a predetermined large value for a predetermined period after the transition. Air conditioner for vehicles.

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