JP5626327B2 - Air conditioner for vehicles - Google Patents

Description

  The present invention relates to a vehicle air conditioner for heating a passenger compartment.

  Conventionally, as this type of vehicle air conditioner, heating is performed by operating a vapor compression refrigeration cycle as a heat pump cycle, or a heat exchanger for heating using cooling water of a vehicle travel engine (internal combustion engine) as a heat source ( There is one that performs heating (hot water heating) using a heater core.

  Patent Document 1 discloses a vehicle air conditioner that is applied to a vehicle that is driven by a battery-driven electric motor that is driven by a battery when traveling in an urban area, and that is driven by an engine when the battery runs out or travels in the suburbs. An apparatus is described.

  In this prior art, the compressor of the heat pump cycle is driven by an electric motor. That is, the heat pump cycle is operated with the power supplied from the battery.

  In this prior art, warm water heating is performed by the heater core while the engine cooling water is warm, and heating is performed by the heat pump cycle when the engine cooling water becomes cold.

  Therefore, in this conventional technology, when the vehicle is driven for a long time by the electric motor for driving the vehicle, in other words, when the engine is stopped for a long time and the engine coolant is cold, the heat pump cycle is used. Heating will be performed.

Japanese Patent Laid-Open No. 5-221233

  In the above-described conventional technology, the heat pump cycle is operated by the power supplied from the battery, so that heating by the heat pump cycle cannot be performed when the battery is exhausted. For this reason, if a battery runs out during heating by a heat pump cycle, it is necessary to switch to hot water heating by a heater core and continue heating.

  However, if the battery runs out when the vehicle is driven by the electric motor for driving the vehicle and the heating by the heat pump cycle is performed, the start of the engine and the switching to the hot water heating by the heater core are performed at the same time. Therefore, even if it switches to warm water heating by a heater core, the situation where engine cooling water becomes cold for a while and a heating capability cannot be exhibited may occur.

  That is, in the above-mentioned conventional technology, even if the battery runs out and switches to heating by the heater core, the heating is interrupted until the temperature of the engine cooling water sufficiently rises and the passenger comfort is impaired. Can occur.

  The present invention has been made in view of the above points, and an object thereof is to improve passenger comfort.

In order to achieve the above object, according to the first aspect of the present invention, there is provided an indoor condenser (12) for exchanging heat between the blown air blown into the vehicle interior and the refrigerant, and the blown air is passed through the indoor condenser (12). A vapor compression refrigeration cycle (10) constituting a heat pump cycle for heating
A casing (31) for housing the indoor condenser (12);
A cooling cold air passage (33) formed in the casing (31) and through which the blown air flows through the indoor condenser (12);
A cold air bypass passage (34) formed in the casing (31) and through which the blown air flows bypassing the indoor condenser (12);
A temperature adjusting means (38) for adjusting the temperature of the blown air by changing the air volume ratio between the blown air flowing through the heating cold air passage (33) and the blown air flowing through the cold air bypass passage (34);
A face outlet (41) for blowing air-conditioned air toward the upper body of the passenger in the passenger compartment, the blown air formed in the casing (31) and adjusted in temperature by the temperature adjusting means (38);
A foot outlet (42) that is formed in the casing (31) and blows air-conditioned air toward the feet of the occupant by blowing air that has been temperature-adjusted by the temperature adjusting means (38);
Air outlet mode switching means for switching between a bi-level mode that opens both the face air outlet (41) and the foot air outlet (42) and a foot mode that closes the face air outlet (41) and opens the foot air outlet (42). 41a, 42a),
Control means (50) for determining the target opening degree of the temperature adjusting means (38) and determining the switching between the bi-level mode and the foot mode,
When the temperature adjusting means (38) fully opens the cooling cold air passage (33) and fully closes the cold air bypass passage (34), the maximum heating position is set.
The control means (50)
Determining the target temperature of the indoor condenser (12) based on the target outlet temperature,
As the target temperature of the indoor condenser (12) is lower, the target opening of the temperature adjusting means (38) is determined as the opening on the maximum heating position side,
Select the foot mode when the target blowout temperature is higher than the predetermined switching temperature,
When the target blowing temperature is lower than the predetermined switching temperature, the bi-level mode is selected,
When the target opening degree of the temperature adjustment means (38) is the opening degree on the maximum heating position side with respect to the predetermined opening degree, the target opening degree of the temperature adjustment means (38) is on the side opposite to the maximum heating position with respect to the predetermined opening degree. The predetermined switching temperature is set to be lower than that when the opening degree is.

  By the way, at the time of heating by the heat pump cycle, it is desirable to save energy by making the target temperature of the indoor condenser (12) as low as possible (close to the target blowing temperature). On the other hand, if the target temperature of the indoor condenser (12) is low, the blowout temperature tends to be low. Therefore, the lower the target temperature of the indoor condenser (12), the higher the target opening degree of the temperature adjusting means (38) is on the maximum heating position side. It is desirable to suppress the reduction of the blowing temperature by opening the opening.

  That is, at the time of heating by the heat pump cycle, if both energy saving and securing of the blowing temperature are to be achieved, the frequency of the target opening degree of the temperature adjusting means (38) near the maximum heating position increases.

  On the other hand, in order to realize the cabin air temperature distribution of head cold heat, the face air outlet (41) is disposed near the cold air bypass passage (34), and the foot air outlet (42) is heated by the cold air passage (33) for heating. It is desirable that the air outlet temperature from the face air outlet (41) is lower than the air outlet temperature from the foot air outlet (42) by disposing it at a position closer to the air outlet.

  However, when the temperature adjusting means (38) is in the vicinity of the maximum heating position, the air volume in the cold air bypass passage (34) becomes very small, so that the air temperature from the face air outlet (41) is reduced from the foot air outlet (42). There is a problem that the occupant becomes uncomfortable, for example, the temperature becomes as high as the blowing temperature, and the occupant's face tends to be hot.

  In particular, when heating by a heat pump cycle, the frequency of the temperature adjusting means (38) near the maximum heating position increases as described above, and this problem becomes significant.

  On the other hand, in the invention according to claim 1, when the target opening degree of the temperature adjusting means (38) is the opening degree on the maximum heating position side with respect to the predetermined opening degree, the target opening degree of the temperature adjusting means (38). Since the switching temperature between the foot mode and the bi-level mode is set lower than when the opening is opposite to the maximum heating position than the predetermined opening, the temperature adjustment means (38) is set to the maximum heating position. When in the vicinity, the bi-level mode in which the face outlet (41) is opened can be made difficult. In other words, it is possible to easily enter a foot mode in which the face outlet (41) is closed.

  For this reason, since it can suppress that warm air blows off from a face blower outlet (41) when a temperature adjustment means (38) exists in the vicinity of a maximum heating position, a passenger | crew's comfort can be improved.

In the invention according to claim 2, a heat exchanger (36) for heating that heats the blown air blown into the passenger compartment by heat exchange with cooling water of the internal combustion engine (EG),
A casing (31) containing a heat exchanger (36) for heating;
A cold air passage for heating (33) formed in the casing (31), and the blown air flows through the heat exchanger for heating (36);
A cold air bypass passage (34) formed in the casing (31) and through which the blown air flows bypassing the heat exchanger (36) for heating;
A temperature adjusting means (38) for adjusting the temperature of the blown air by changing the air volume ratio between the blown air flowing through the heating cold air passage (33) and the blown air flowing through the cold air bypass passage (34);
A face outlet (41) for blowing air-conditioned air toward the upper body of the passenger in the passenger compartment, the blown air formed in the casing (31) and adjusted in temperature by the temperature adjusting means (38);
A foot outlet (42) that is formed in the casing (31) and blows air-conditioned air toward the feet of the occupant by blowing air that has been temperature-adjusted by the temperature adjusting means (38);
Air outlet mode switching means for switching between a bi-level mode that opens both the face air outlet (41) and the foot air outlet (42) and a foot mode that closes the face air outlet (41) and opens the foot air outlet (42) ( 41a, 42a),
Control means (50) for determining the target opening degree of the temperature adjusting means (38) and determining the switching between the bi-level mode and the foot mode,
When the temperature adjusting means (38) fully opens the cooling cold air passage (33) and fully closes the cold air bypass passage (34), the maximum heating position is set.
The control means (50)
As the temperature of the cooling water is lower, the target opening degree of the temperature adjusting means (38) is determined as the opening degree on the maximum heating position side,
Select the foot mode when the target blowout temperature is higher than the predetermined switching temperature,
When the target blowing temperature is lower than the predetermined switching temperature, the bi-level mode is selected,
When the temperature of the cooling water is lower than the predetermined temperature, the predetermined switching temperature is set lower than when the temperature of the cooling water is higher than the predetermined temperature.

  By the way, at the time of hot water heating by the heat exchanger for heating (36) (at the time of heating using the cooling water as a heat source), the lower the temperature of the cooling water, the lower the target opening degree of the temperature adjusting means (38) to the maximum heating position side. It is desirable to suppress the reduction of the blowing temperature by opening the opening.

  That is, if it is going to ensure blowing temperature even if the temperature of cooling water is low, the frequency which the target opening degree of a temperature control means (38) will become near the maximum heating position becomes high.

  On the other hand, in order to realize the cabin air temperature distribution of head cold heat, the face air outlet (41) is disposed near the cold air bypass passage (34), and the foot air outlet (42) is heated by the cold air passage (33) for heating. It is desirable that the air outlet temperature from the face air outlet should be lower than the air outlet temperature from the foot air outlet.

  However, when the temperature adjusting means (38) is in the vicinity of the maximum heating position, the air volume in the cold air bypass passage (34) is very small, so that the air outlet temperature from the face outlet is the same as the outlet temperature from the foot outlet. There is a problem that the occupant becomes uncomfortable, for example, the height of the occupant increases and the occupant's face tends to be hot.

  In particular, when the temperature of the cooling water is low, the frequency of the temperature adjusting means (38) near the maximum heating position increases as described above, and this problem becomes significant.

  On the other hand, in the invention according to claim 2, when the temperature of the cooling water is lower than the predetermined temperature, the foot mode and the bi-level mode are compared with the case where the temperature of the cooling water is higher than the predetermined temperature. Since the switching temperature is set low, when the temperature adjusting means (38) is in the vicinity of the maximum heating position, the bi-level mode in which the face air outlet (41) is opened can be prevented. In other words, it is possible to easily enter a foot mode in which the face outlet (41) is fully closed.

  For this reason, since it can suppress that warm air blows off from a face blower outlet when a temperature adjustment means (38) exists in the vicinity of a maximum heating position, a passenger | crew's comfort can be improved.

According to a third aspect of the present invention, in the vehicular air conditioner according to the first aspect, the vapor compression refrigeration cycle (10) has a compressor (11) that compresses and discharges the refrigerant, and a cold air passage for heating. (33) includes a hot water heating means (36) for heating the blown air using the cooling water of the internal combustion engine (EG) as a heat source , and the control means (50) is a component of the vapor compression refrigeration cycle (10). There characterized and Turkey to output an actuation request signal to the internal combustion engine (EG) when it is determined that it has failed.

  According to this, when a component of the vapor compression refrigeration cycle (10) breaks down and heating by the heat pump cycle cannot be performed, switching to hot water heating by the hot water heating means (36) (heating using cooling water as a heat source) is performed. Therefore, even if the components of the vapor compression refrigeration cycle (10) break down, the heating can be continued without interruption. As a result, passenger comfort can be improved.

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

It is a block diagram of the vehicle air conditioner in 1st Embodiment of this invention, and the time of air_conditioning | cooling mode is shown. It is a block diagram of the vehicle air conditioner in 1st Embodiment of this invention, and the time of heating mode is shown. It is a block diagram of the vehicle air conditioner in 1st Embodiment of this invention, and the time of 1st dehumidification mode is shown. It is a block diagram of the vehicle air conditioner in 1st Embodiment of this invention, and the time of 2nd dehumidification mode is shown. It is a block diagram of the electric control part of the vehicle air conditioner of 1st Embodiment. It is a flowchart which shows the control processing of the vehicle air conditioner of 1st Embodiment. It is a flowchart which shows the detail of step S14 of FIG. It is a graph which shows the dehumidification capability and heating capability in each operation mode of the vehicle air conditioner of 1st Embodiment. It is a flowchart which shows the principal part of step S16 of 1st Embodiment. It is a flowchart which shows the principal part of step S6 of 1st Embodiment. It is a flowchart which shows the principal part of the control processing of 2nd Embodiment. It is a flowchart which shows the principal part of the control processing of 3rd Embodiment. It is a flowchart which shows the principal part of step S10 of 4th Embodiment. It is a flowchart which shows the principal part of step S9 of 4th Embodiment. It is a flowchart which shows the principal part of the control processing of 5th Embodiment.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the vehicle air conditioner of the present invention is applied to a so-called hybrid vehicle that obtains a driving force for vehicle traveling from an internal combustion engine (engine) EG and a traveling electric motor MG. 1 to 4 are overall configuration diagrams of the vehicle air conditioner 1.

  The vehicle air conditioner includes a cooling mode (COOL cycle) for cooling the passenger compartment, a heating mode (HOT cycle) for heating the passenger compartment, a first dehumidifying mode (DRY_EVA cycle) for dehumidifying the passenger compartment and a second dehumidifying mode ( (DRY_ALL cycle) is provided with a vapor compression refrigeration cycle 10 configured to be able to switch a refrigerant circuit. 1 to 4 respectively show the flow of the refrigerant in the cooling mode, the heating mode, and the first and second dehumidifying modes with solid arrows.

  The cooling mode is a mode in which the refrigeration cycle 10 is operated as a cooler cycle, and has a cooling capacity and a dehumidifying capacity. Therefore, the cooling mode can also be expressed as a cooling and dehumidifying mode.

  The heating mode and the first and second dehumidifying modes are modes in which the refrigeration cycle 10 is operated as a heat pump cycle. Of the three modes by this heat pump cycle, the heating mode has a high heating capability but does not have a dehumidifying capability. Therefore, the heating mode can also be expressed as a heat pump cycle without dehumidification.

  Of the three modes based on the heat pump cycle, the first and second dehumidifying modes have dehumidifying ability but the heating ability is inferior to the heating mode. Therefore, the first and second dehumidification modes can also be expressed as a heat pump cycle with dehumidification.

  More specifically, the first dehumidifying mode is a dehumidifying mode that prioritizes the dehumidifying capacity over the heating capacity, and the second dehumidifying mode is a dehumidifying mode that prioritizes the heating capacity over the dehumidifying capacity. Therefore, the first dehumidification mode can be expressed as a low temperature dehumidification mode or a simple dehumidification mode, and the second dehumidification mode can be expressed as a high temperature dehumidification mode or a dehumidification heating mode.

  Incidentally, the chart of FIG. 8 shows a comparison of the dehumidifying capacity and the heating capacity in the cooling mode, the heating mode, and the first and second dehumidifying modes. That is, in the cooling mode, the dehumidifying capacity is the largest, but there is no heating capacity. Therefore, when the cooling mode is selected during heating, heating means other than the refrigeration cycle 10 (in this example, a heater core 36 and a PTC heater 37 described later) are used in combination.

  In the heating mode, there is no dehumidification capability, but the heating capability is the largest. In the first dehumidifying mode, the dehumidifying capacity is moderate, but the heating capacity is small. In the second dehumidifying mode, the dehumidifying capacity is small, but the heating capacity is medium.

  The refrigeration cycle 10 includes a compressor 11, an indoor condenser 12 and an indoor evaporator 26 as indoor heat exchangers, a temperature expansion valve 27 and a fixed throttle 14 as decompression means for decompressing and expanding the refrigerant, and a refrigerant circuit switching means. As a plurality (5 in this embodiment) of electromagnetic valves 13, 17, 20, 21, 24, and the like.

  Further, the refrigeration cycle 10 employs a normal chlorofluorocarbon refrigerant as the refrigerant, and constitutes a subcritical refrigeration cycle in which the high-pressure side refrigerant pressure does not exceed the critical pressure of the refrigerant. Furthermore, this refrigerant is mixed with refrigerating machine oil for lubricating the compressor 11, and this refrigerating machine oil circulates in the cycle together with the refrigerant.

  The compressor 11 is disposed in the engine room, sucks the refrigerant in the refrigeration cycle 10, compresses it, and discharges it. The electric motor 11b drives the fixed capacity compression mechanism 11a having a fixed discharge capacity. It is configured as a compressor. Specifically, various types of compression mechanisms such as a scroll type compression mechanism and a vane type compression mechanism can be adopted as the fixed capacity type compression mechanism 11a.

  The electric motor 11b is an AC motor whose operation (number of rotations) is controlled by the AC voltage output from the inverter 61. Further, the inverter 61 outputs an AC voltage having a frequency corresponding to a control signal output from the air conditioning control device 50 described later. And the refrigerant | coolant discharge capability of the compressor 11 is changed by this rotation speed control. Therefore, the electric motor 11b constitutes a discharge capacity changing unit of the compressor 11.

  Supply of electric power to the inverter 61 is performed from the battery BT. The battery BT also supplies power to the traveling electric motor MG.

  The refrigerant inlet side of the indoor condenser 12 is connected to the discharge side of the compressor 11. The indoor condenser 12 is disposed in a casing 31 that forms an air passage for the blown air that is blown into the vehicle interior in the indoor air conditioning unit 30 of the vehicle air conditioner, and a refrigerant that circulates in the casing 31 and an indoor evaporator described later. It is a heat exchanger for heating which heats blowing air by heat-exchanging with blowing air after passing 26. The details of the indoor air conditioning unit 30 will be described later.

  An electric three-way valve 13 is connected to the refrigerant outlet side of the indoor condenser 12. The electric three-way valve 13 is refrigerant circuit switching means whose operation is controlled by a control voltage output from the air conditioning control device 50.

  More specifically, the electric three-way valve 13 switches to a refrigerant circuit that connects between the refrigerant outlet side of the indoor condenser 12 and the refrigerant inlet side of the fixed throttle 14 in an energized state in which electric power is supplied. In the non-energized state in which the supply of the refrigerant is stopped, the refrigerant circuit is switched to a refrigerant circuit that connects between the refrigerant outlet side of the indoor condenser 12 and one refrigerant inlet / outlet of the first three-way joint 15.

  The fixed throttle 14 is a dehumidifying means for heating and dehumidifying that decompresses and expands the refrigerant flowing out of the electric three-way valve 13 in the heating mode and the first and second dehumidifying modes. As the fixed throttle 14, a capillary tube, an orifice, or the like can be employed. Of course, an electric variable throttle mechanism in which the throttle passage area is adjusted by a control signal output from the air-conditioning control device 50 may be employed as the decompression means for heating and dehumidification. A refrigerant inlet / outlet port of a third three-way joint 23 described later is connected to the refrigerant outlet side of the fixed throttle 14.

  The first three-way joint 15 has three refrigerant inflow / outflow ports and functions as a branching portion that branches the refrigerant flow path. Such a three-way joint may be constituted by joining refrigerant pipes, or may be constituted by providing a plurality of refrigerant passages in a metal block or a resin block. In addition, one refrigerant inlet / outlet of the outdoor heat exchanger 16 is connected to another refrigerant inlet / outlet of the first three-way joint 15, and the refrigerant inlet side of the low-pressure solenoid valve 17 is connected to another refrigerant inlet / outlet. ing.

  The low pressure solenoid valve 17 has a valve body portion that opens and closes the refrigerant flow path and a solenoid (coil) that drives the valve body portion, and the operation of which is controlled by a control voltage output from the air conditioning control device 50. Circuit switching means. More specifically, the low-pressure solenoid valve 17 is configured as a so-called normally closed on-off valve that opens in an energized state and closes in a non-energized state.

  One refrigerant inlet / outlet port of a fifth three-way joint 28 described later is connected to the refrigerant outlet side of the low pressure solenoid valve 17 via the first check valve 18. The first check valve 18 only allows the refrigerant to flow from the low pressure solenoid valve 17 side to the fifth three-way joint 28 side.

  The outdoor heat exchanger 16 is disposed in the engine room, and exchanges heat between the refrigerant circulating inside and the air outside the vehicle (outside air) blown from the blower fan 16a. The blower fan 16 a is an electric blower in which the rotation speed (the amount of blown air) is controlled by a control voltage output from the air conditioning control device 50.

  Further, the blower fan 16a of the present embodiment blows outdoor air not only to the outdoor heat exchanger 16 but also to a radiator (not shown) that dissipates the cooling water of the engine EG. Specifically, the vehicle exterior air blown from the blower fan 16a flows in the order of the outdoor heat exchanger 16 → the radiator.

  Moreover, the cooling water circuit shown by the broken line of FIGS. 1-4 is arrange | positioned with the cooling water pump which is not shown in order to circulate cooling water. This cooling water pump is an electric water pump whose rotation speed (cooling water circulation amount) is controlled by a control voltage output from the air conditioning control device 50.

  One refrigerant inlet / outlet of the second three-way joint 19 is connected to the other refrigerant inlet / outlet of the outdoor heat exchanger 16. The basic configuration of the second three-way joint 19 is the same as that of the first three-way joint 15. Further, the refrigerant inlet side of the high-pressure solenoid valve 20 is connected to another refrigerant inlet / outlet of the second three-way joint 19, and one refrigerant inlet / outlet of the heat exchanger cutoff electromagnetic valve 21 is connected to another refrigerant inlet / outlet. It is connected.

  The high-pressure solenoid valve 20 and the heat exchanger shut-off solenoid valve 21 are refrigerant circuit switching means whose operation is controlled by a control voltage output from the air conditioning control device 50. It is the same. However, the high-pressure solenoid valve 20 and the heat exchanger shut-off solenoid valve 21 are configured as so-called normally open type on-off valves that close in an energized state and open in a non-energized state.

  The refrigerant outlet side of the high-pressure solenoid valve 20 is connected via a second check valve 22 to the throttle mechanism portion inlet side of a temperature type expansion valve 27 described later. The second check valve 22 only allows the refrigerant to flow from the high pressure solenoid valve 20 side to the temperature type expansion valve 27 side.

  One refrigerant inlet / outlet of the third three-way joint 23 is connected to the other refrigerant inlet / outlet of the heat exchanger cutoff electromagnetic valve 21. The basic configuration of the third three-way joint 23 is the same as that of the first three-way joint 15. Further, as described above, the refrigerant outlet side of the fixed throttle 14 is connected to another refrigerant inlet / outlet of the third three-way joint 23, and the refrigerant inlet side of the dehumidifying electromagnetic valve 24 is connected to another refrigerant inlet / outlet. Yes.

  The dehumidifying electromagnetic valve 24 is a refrigerant circuit switching means whose operation is controlled by a control voltage output from the air conditioning control device 50, and its basic configuration is the same as that of the low-pressure electromagnetic valve 17. Further, the dehumidifying electromagnetic valve 24 is also configured as a normally closed type on-off valve. The refrigerant circuit switching means of the present embodiment is constituted by a plurality of (five) solenoid valves including an electric three-way valve 13, a low pressure solenoid valve 17, a high pressure solenoid valve 20, a heat exchanger cutoff solenoid valve 21, and a dehumidification solenoid valve 24. Composed.

  One refrigerant inlet / outlet of the fourth three-way joint 25 is connected to the refrigerant outlet side of the dehumidifying electromagnetic valve 24. The basic configuration of the fourth three-way joint 25 is the same as that of the first three-way joint 15. Further, another refrigerant inlet / outlet of the fourth three-way joint 25 is connected to the throttle mechanism outlet side of the temperature type expansion valve 27, and further, the refrigerant inlet side of the indoor evaporator 26 is connected to another refrigerant inlet / outlet. Yes.

  The indoor evaporator 26 is disposed in the casing 31 of the indoor air-conditioning unit 30 on the upstream side of the blower air flow of the indoor condenser 12, and exchanges heat between the refrigerant circulating in the interior and the blown air so that the blown air is exchanged. A cooling heat exchanger for cooling.

  The temperature-sensing part inlet side of the temperature type expansion valve 27 is connected to the refrigerant outlet side of the indoor evaporator 26. The temperature type expansion valve 27 is a decompression means for cooling that decompresses and expands the refrigerant that has flowed in from the inlet of the throttle mechanism part and flows out from the outlet of the throttle mechanism part to the outside.

  More specifically, in the present embodiment, as the temperature type expansion valve 27, a temperature sensing unit 27a that detects the degree of superheat of the refrigerant on the outlet side of the indoor evaporator 26 based on the temperature and pressure of the refrigerant on the outlet side of the indoor evaporator 26; And a variable throttle mechanism 27b that adjusts the throttle passage area (refrigerant flow rate) so that the degree of superheat of the refrigerant on the outlet side of the indoor evaporator 26 falls within a predetermined range according to the displacement of the temperature sensing unit 27a. An internal pressure equalizing expansion valve housed inside is adopted.

  One refrigerant inlet / outlet of the fifth three-way joint 28 is connected to the temperature sensing part outlet side of the temperature type expansion valve 27. The basic configuration of the fifth three-way joint 28 is the same as that of the first three-way joint 15. Further, as described above, the refrigerant outlet side of the first check valve 18 is connected to another refrigerant inlet / outlet of the fifth three-way joint 28, and the refrigerant inlet side of the accumulator 29 is connected to another refrigerant inlet / outlet. ing.

  The accumulator 29 is a low-pressure side gas-liquid separator that separates the gas-liquid refrigerant flowing into the fifth three-way joint 28 and stores excess refrigerant. Further, the refrigerant inlet of the compressor 11 is connected to the gas-phase refrigerant outlet of the accumulator 29.

  Next, the indoor air conditioning unit 30 will be described. The indoor air conditioning unit 30 is disposed inside the instrument panel (instrument panel) at the foremost part of the vehicle interior, and has a blower 32, the above-described indoor evaporator 26, the indoor condenser 12, The heater core 36, the PTC heater 37, etc. are accommodated.

  The casing 31 forms an air passage for blown air that is blown into the vehicle interior, and is formed of a resin (for example, polypropylene) that has a certain degree of elasticity and is excellent in strength. On the most upstream side of the blast air flow in the casing 31, an inside / outside air switching box 40 for switching and introducing inside air (vehicle compartment air) and outside air (vehicle compartment outside air) is disposed.

  More specifically, the inside / outside air switching box 40 is formed with an inside air introduction port 40a for introducing inside air into the casing 31 and an outside air introduction port 40b for introducing outside air. Furthermore, inside / outside air switching box 40, an inside / outside air switching door that continuously adjusts the opening areas of inside air introduction port 40a and outside air introduction port 40b to change the air volume ratio between the air volume of the inside air and the air volume of the outside air. 40c is arranged.

  Therefore, the inside / outside air switching door 40c constitutes an air volume ratio changing means for switching the suction port mode for changing the air volume ratio between the air volume of the inside air introduced into the casing 31 and the air volume of the outside air. More specifically, the inside / outside air switching door 40c is driven by an electric actuator 62 for the inside / outside air switching door 40c, and the operation of the electric actuator 62 is controlled by a control signal output from the air conditioning controller 50. The

  As the suction port mode, the inside air introduction port 40a is fully opened and the outside air introduction port 40b is fully closed to introduce the inside air into the casing 31, and the inside air introduction port 40a is fully closed and the outside air introduction port 40b. The outside air mode in which the outside air is introduced into the casing 31 with the valve fully opened, and the opening areas of the inside air introduction port 40a and the outside air introduction port 40b are continuously adjusted between the inside air mode and the outside air mode. There is an internal / external air mixing mode that continuously changes the introduction ratio.

  On the downstream side of the air flow of the inside / outside air switching box 40, a blower 32 that blows air sucked through the inside / outside air switching box 40 toward the vehicle interior is arranged. The blower 32 is an electric blower that drives a centrifugal multiblade fan (sirocco fan) with an electric motor, and the number of rotations (air flow rate) is controlled by a control voltage output from the air conditioning control device 50.

  The indoor evaporator 26 is disposed on the downstream side of the air flow of the blower 32. Further, on the downstream side of the air flow of the indoor evaporator 26, an air passage such as a cooling cold air passage 33 and a cold air bypass passage 34 for flowing air after passing through the indoor evaporator 26, and a heating cold air passage 33 and a cold air bypass passage 34. A mixing space 35 is formed for mixing the air that has flowed out of the air.

  In the heating cool air passage 33, a heater core 36, an indoor condenser 12, and a PTC heater 37 as heating means for heating the air that has passed through the indoor evaporator 26 are arranged in this order in the air flow direction. Has been.

  The heater core 36 performs heat exchange between the cooling water (hot water) of the engine EG that outputs a driving force for vehicle travel and the air that has passed through the indoor evaporator 26, and heat for heating the air that has passed through the indoor evaporator 26. It is an exchanger. Therefore, the heater core 36 can also be expressed as hot water heating means.

  The PTC heater 37 is an electric heater that has a PTC element (positive characteristic thermistor), generates heat when supplied with electric power, and heats air after passing through the indoor condenser 12. In addition, the PTC heater 37 of this embodiment is provided with two or more (specifically three), and the air-conditioning control apparatus 50 changes the number of the PTC heaters 37 to energize, and thereby the plurality of PTC heaters 37. The overall heating capacity is controlled.

  On the other hand, the cold air bypass passage 34 is an air passage for guiding the air after passing through the indoor evaporator 26 to the mixing space 35 without passing through the heater core 36, the indoor condenser 12, and the PTC heater 37. Accordingly, the temperature of the blown air mixed in the mixing space 35 varies depending on the air volume ratio of the air passing through the heating cool air passage 33 and the air passing through the cold air bypass passage 34.

  Therefore, in the present embodiment, the cold air flowing into the heating cold air passage 33 and the cold air bypass passage 34 on the downstream side of the air flow of the indoor evaporator 26 and on the inlet side of the heating cold air passage 33 and the cold air bypass passage 34 is supplied. An air mix door 38 that continuously changes the air volume ratio is disposed.

  Therefore, the air mix door 38 constitutes a temperature adjusting means for adjusting the air temperature in the mixing space 35 (the temperature of the blown air blown into the vehicle interior). More specifically, the air mix door 38 is driven by an electric actuator 63 for the air mix door, and the operation of the electric actuator 63 is controlled by a control signal output from the air conditioning control device 50.

  Furthermore, blower outlets 41 to 43 that blow out the blown air whose temperature is adjusted from the mixing space 35 to the vehicle interior that is the space to be cooled are disposed at the most downstream portion of the blown air flow of the casing 31. Specifically, the air outlets 41 to 43 include a face air outlet 41 that blows air-conditioned air toward the upper body of the passenger in the vehicle interior, a foot air outlet 42 that blows air-conditioned air toward the feet of the passenger, and the front surface of the vehicle. A defroster outlet 43 that blows air-conditioned air toward the inner side surface of the window glass is provided.

  Further, on the upstream side of the air flow of the face air outlet 41, the foot air outlet 42, and the defroster air outlet 43, the face door 41a for adjusting the opening area of the face air outlet 41 and the opening area of the foot air outlet 42 are adjusted. The defroster door 43a which adjusts the opening area of the foot door 42a to perform and the defroster blower outlet 43 is arrange | positioned.

  The face door 41a, the foot door 42a, and the defroster door 43a constitute an outlet mode switching means for switching the outlet mode, and an electric actuator 64 for driving the outlet mode door through a link mechanism (not shown). It is linked to and rotated in conjunction with it. The operation of the electric actuator 64 is also controlled by a control signal output from the air conditioning controller 50.

  As the air outlet mode, the face air outlet 41 is fully opened and air is blown out from the face air outlet 41 toward the upper body of the passenger in the vehicle. Both the face air outlet 41 and the foot air outlet 42 are opened. Bi-level mode that blows air toward the upper body and feet of passengers in the passenger compartment, the face air outlet 41 is fully closed, the foot air outlet 42 is fully opened, and the defroster air outlet 43 is opened by a small opening, and the foot air outlet There are a foot mode in which mainly air is blown out from 42 and a foot defroster mode in which the foot air outlet 42 and the defroster air outlet 43 are opened to the same extent and air is blown out from both the foot air outlet 42 and the defroster air outlet 43.

  Further, the defroster mode in which the occupant manually operates the air outlet mode switch 60c of the operation panel 60 described later to fully open the defroster air outlet 43 and blow out air from the defroster air outlet 43 to the inner surface of the front windshield of the vehicle. it can.

  In short, when the foot mode is selected as the air outlet mode, air is blown out from at least the foot air outlet 42, and when the foot defroster mode or the defroster mode is selected, the air volume ratio of the air blown out from the defroster air outlet 43 More than in foot mode, window fogging is prevented. Therefore, the foot defroster mode and the defroster mode can also be expressed as an anti-fogging mode.

  In addition, the hybrid vehicle to which the vehicle air conditioner 1 of the present embodiment is applied includes an electric heat defogger 47 and a seat heating device 48 separately from the vehicle air conditioner. The electric heat defogger 47 is a heating wire arranged inside or on the surface of the vehicle interior window glass, and is a window glass heating means for preventing fogging or eliminating window fogging by heating the window glass.

  The seat heating device 48 is a heating device arranged inside or on the surface of a seat (seat), and warms the occupant's body directly to effectively enhance the occupant's thermal sensation. In this example, a heating wire that generates heat when energized is used as the seat heating device 48.

  The operation of the electric heat defogger 47 and the seat heating device 48 can also be controlled by a control signal output from the air conditioning control device 50.

  Next, the electric control unit of this embodiment will be described with reference to FIG. The air conditioning control device 50 is composed of a well-known microcomputer including a CPU, ROM, RAM, and its peripheral circuits, and performs various calculations and processing based on an air conditioning control program stored in the ROM, and is connected to the output side. The inverter 61 for the electric motor 11b of the compressor 11, the solenoid valves 13, 17, 20, 21, 24 constituting the refrigerant circuit switching means, the blower fan 16a, the blower 32, various electric actuators 62, 63, 64, etc. Control the operation of

  In addition, the air-conditioning control device 50 is configured such that control means for controlling the various devices described above is integrally configured. For example, the air conditioning control device 50 constitutes a control unit that performs switching control between the above-described cooling mode, heating mode, and first and second dehumidifying modes.

  In the present embodiment, in particular, a configuration (hardware and software) that controls the operation (refrigerant discharge capability) of the electric motor 11b that is a discharge capability changing unit of the compressor 11 is referred to as a discharge capability control unit 50a. Of course, the discharge capacity control means 50a may be configured separately from the air conditioning control device 50.

  Further, on the input side of the air-conditioning control device 50, an inside air sensor 51 that detects the vehicle interior temperature Tr, an outside air sensor 52 (outside air temperature detection means) that detects the outside air temperature Tam, and a solar radiation sensor that detects the amount of solar radiation Ts in the vehicle interior. 53, a discharge temperature sensor 54 (discharge temperature detection means) for detecting the compressor 11 discharge refrigerant temperature Td, a discharge pressure sensor 55 (discharge pressure detection means) for detecting the compressor 11 discharge refrigerant pressure Pd, and from the indoor evaporator 26. An evaporator temperature sensor 56 (evaporator temperature detecting means) that detects the blown air temperature (evaporator temperature) Te, an intake temperature that detects the temperature Tsi of the refrigerant flowing between the first three-way joint 15 and the low pressure solenoid valve 17. Sensor 57, coolant temperature sensor for detecting engine coolant temperature Tw, and RHW sensor 45 for detecting a detection value necessary for calculating relative humidity RHW of the window glass surface (window glass) Detection signals of the surface relative humidity detecting means) a group of sensors or the like are input. Here, the window glass surface relative humidity RHW is the relative humidity of the window glass indoor side surface.

  In addition, the evaporator temperature sensor 56 of the present embodiment specifically detects the heat exchange fin temperature of the indoor evaporator 26. Of course, as the evaporator temperature sensor 56, temperature detection means for detecting the temperature of other parts of the indoor evaporator 26 may be employed, or temperature detection for directly detecting the temperature of the refrigerant itself flowing through the indoor evaporator 26. Means may be employed.

  In addition, the RHW sensor 45 of the present embodiment is specifically a humidity sensor that detects the relative humidity of the vehicle interior air near the window glass in the vehicle interior, and the vicinity of the window glass that detects the temperature of the vehicle interior air near the window glass. It consists of three sensors, a temperature sensor and a window glass surface temperature sensor that detects the window glass surface temperature.

  In this example, the RHW sensor 45 is disposed on the vehicle interior side surface of the vehicle window glass (for example, right next to the rearview mirror at the center upper portion of the vehicle front window glass).

  Further, operation signals from various air conditioning operation switches provided on the operation panel 60 disposed near the instrument panel in the front part of the vehicle interior are input to the input side of the air conditioning control device 50. As various air conditioning operation switches provided on the operation panel 60, specifically, an operation switch (not shown) of the vehicle air conditioner 1 and an air conditioner on / off (specifically, the compressor 11 is on / off). An air conditioner switch 60a for switching, an auto switch (not shown) for setting / releasing automatic control of the vehicle air conditioner 1, an operation mode changeover switch (not shown), a suction port mode switch 60b for switching the suction port mode, An outlet mode switch 60c for switching the outlet mode, an air volume setting switch (not shown) of the blower 32, an interior temperature setting switch (not shown), and an economy switch (priority) for outputting a command to prioritize power saving of the refrigeration cycle Etc.) are provided.

  Next, the operation of this embodiment in the above configuration will be described with reference to FIG. FIG. 6 is a flowchart showing a control process of the vehicle air conditioner 1 of the present embodiment. This control process is executed by supplying power from the battery BT to the air conditioning control device 50 even when the vehicle system is stopped.

  First, in step S1, it is determined whether or not the pre-air conditioning start switch or the operation switch of the vehicle air conditioner 1 on the operation panel 60 is turned on. When the pre-air conditioning start switch or the operation switch of the vehicle air conditioner 1 is turned on, the process proceeds to step S2.

  Note that pre-air conditioning is air conditioning control that starts air conditioning in the passenger compartment before a passenger gets into the vehicle. The pre-air conditioning start switch is provided in a wireless terminal (remote control) carried by the passenger. Therefore, the occupant can start the vehicle air conditioner 1 from a location away from the vehicle.

  Furthermore, in the hybrid vehicle to which the vehicle air conditioner 1 of the present embodiment is applied, the battery BT can be charged by supplying power from the commercial power source (external power source) to the battery BT. Therefore, the pre-air conditioning is performed for a predetermined time (for example, 30 minutes) when the vehicle is connected to the external power source, and when the vehicle is not connected to the external power source, the remaining amount of the battery BT becomes a predetermined amount or less. Until now.

  In step S2, initialization of a flag, a timer, etc., initial alignment of the stepping motor constituting the electric actuator described above, and the like are performed. In the next step S3, the operation signal of the operation panel 60 is read and the process proceeds to step S4. Specific operation signals include a vehicle interior set temperature Tset set by a vehicle interior temperature setting switch, an air outlet mode selection signal, a suction port mode selection signal, an air volume setting signal of the blower 32, and the like.

In step S4, the vehicle environmental state signal used for air conditioning control, that is, the detection signals of the sensor groups 51 to 57 described above is read, and the process proceeds to step S5. In step S5, a target blowing temperature TAO of the vehicle cabin blowing air is calculated. Further, in the heating mode, the heating heat exchanger target temperature is calculated. The target blowing temperature TAO is calculated by the following formula F1. TAO = Kset × Tset−Kr × Tr−Kam × Tam−Ks × Ts + C (F1)
Here, Tset is the vehicle interior set temperature set by the vehicle interior temperature setting switch, Tr is the vehicle interior temperature (inside air temperature) detected by the inside air sensor 51, Tam is the outside air temperature detected by the outside air sensor 52, and Ts is This is the amount of solar radiation detected by the solar radiation sensor 53. Kset, Kr, Kam, Ks are control gains, and C is a correction constant.

  Further, the heating heat exchanger target temperature is basically a value calculated by the above formula F1, but is corrected to a value lower than the TAO calculated by the formula F1 in order to reduce power consumption. May be performed.

  In subsequent steps S6 to S16, control states of various devices connected to the air conditioning control device 50 are determined. First, in step S6, the cooling mode, the heating mode, the first dehumidifying mode and the second dehumidifying mode are selected and whether the PTC heater 37 is energized is determined according to the air conditioning environment state. More detailed contents of step S6 of this embodiment will be described later.

  In step S <b> 7, a target air blowing amount of air blown by the blower 32 is determined. Specifically, the blower motor voltage to be applied to the electric motor is determined with reference to a control map stored in advance in the air conditioning control device 50 based on the TAO determined in step S4.

  Specifically, in this embodiment, the blower motor voltage is set to a high voltage near the maximum value in the extremely low temperature region (maximum cooling region) and the extremely high temperature region (maximum heating region) of TAO, and the air volume of the blower 32 is near the maximum air volume. To control. Further, when TAO rises from the extremely low temperature region toward the intermediate temperature region, the blower motor voltage is decreased according to the increase in TAO, and the air volume of the blower 32 is decreased.

  Further, when TAO decreases from the extremely high temperature range toward the intermediate temperature range, the blower motor voltage is decreased in accordance with the decrease in TAO, and the air volume of the blower 32 is decreased. When TAO enters a predetermined intermediate temperature range, the blower motor voltage is set to the minimum value and the air volume of the blower 32 is set to the minimum value.

  In step S8, the inlet mode, that is, the switching state of the inside / outside air switching box 40 is determined. This inlet mode is also determined based on TAO with reference to a control map stored in advance in the air conditioning controller 50. In the present embodiment, priority is given mainly to the outside air mode for introducing outside air. However, the inside air mode for introducing inside air is selected when TAO is in a very low temperature range and high cooling performance is desired. Further, an exhaust gas concentration detecting means for detecting the exhaust gas concentration of the outside air may be provided, and the inside air mode may be selected when the exhaust gas concentration becomes equal to or higher than a predetermined reference concentration.

  In step S9, the air outlet mode is determined. This air outlet mode is also determined with reference to a control map stored in advance in the air conditioning control device 50 based on TAO. In this embodiment, as the TAO rises from the low temperature range to the high temperature range, the outlet mode is sequentially switched from the foot mode to the bi-level mode to the face mode.

  Accordingly, the face mode is mainly selected in the summer, the bi-level mode is mainly selected in the spring and autumn, and the foot mode is mainly selected in the winter. Furthermore, when there is a high possibility that fogging will occur on the window glass from the detection value of the humidity sensor, the foot defroster mode or the defroster mode may be selected.

  In step S10, the target opening degree SW of the air mix door 38 is calculated based on the TAO, the air temperature Te blown from the indoor evaporator 26 detected by the evaporator temperature sensor 56, and the heater temperature.

Here, the heater temperature is a value determined according to the heating capability of the heating means (the heater core 36, the indoor condenser 12, and the PTC heater 37) arranged in the cold air passage 33 for heating, and specifically The engine coolant temperature Tw can be used for the. Therefore, the target opening degree SW can be calculated by the following formula F2. SW = [(TAO−Te) / (Tw−Te)] × 100 (%) (F2)
SW = 0 (%) is the maximum cooling position of the air mix door 38, and the cold air bypass passage 34 is fully opened and the heating cold air passage 33 is fully closed. On the other hand, SW = 100 (%) is the maximum heating position of the air mix door 38, and the cold air bypass passage 34 is fully closed and the heating cold air passage 33 is fully opened.

  In step S11, the refrigerant discharge capacity (specifically, the rotational speed) of the compressor 11 is determined. The basic method for determining the rotational speed of the compressor 11 of the present embodiment is as follows. For example, in the cooling mode, the target blowing temperature TEO of the blowing air temperature Te from the indoor evaporator 26 is determined by referring to the control map stored in advance in the air conditioning control device 50 based on the TAO determined in step S4. decide.

  Then, a deviation En (TEO-Te) between the target blowing temperature TEO and the blowing air temperature Te is calculated, and a deviation change rate obtained by subtracting the deviation En-1 and the previously calculated deviation En-1 from the deviation En calculated this time. Based on fuzzy reasoning based on membership functions and rules stored in advance in the air-conditioning control device 50 using Edot (En− (En−1)), the rotation with respect to the previous compressor speed fCn−1 The number change amount ΔfC is obtained.

  In the heating mode, the target high pressure PDO of the discharge refrigerant pressure Pd is determined with reference to the control map stored in advance in the air conditioning control device 50 based on the heating heat exchanger target temperature determined in step S4. Then, a deviation Pn (PDO−Pd) between the target high pressure PDO and the discharge refrigerant pressure Pd is calculated. Furthermore, using this deviation Pn and deviation change rate Pdot (Pn− (Pn−1)) with respect to previously calculated deviation Pn−1, based on fuzzy inference, A rotation speed change amount ΔfH is obtained.

  In step S12, the operating rate of the blower fan 16a that blows outside air toward the outdoor heat exchanger 16 is determined. The basic method for determining the operating rate of the blower fan 16a of the present embodiment is as follows. That is, the first temporary operating rate is determined so that the operating rate of the blower fan 16a increases as the compressor 11 discharge refrigerant temperature Td increases, and the operating of the blower fan 16a increases as the engine cooling water temperature Tw increases. The second temporary operation rate is determined so that the rate increases.

  Further, the larger one of the first and second temporary operating rates is selected, and the value obtained by correcting the selected operating rate in consideration of noise reduction of the blower fan 16a and the vehicle speed is used. Decide on the rate. More detailed contents of step S12 of this embodiment will be described later.

  In step S13, the number of operating PTC heaters 37 and the operating state of the electric heat defogger 47 are determined. For example, when the PTC heater 37 is energized in step S6, even if the target opening degree SW of the air mix door 38 becomes 100% in the heating mode, What is necessary is just to determine according to the difference of internal temperature Tr and the heat exchanger target temperature for heating, when the heat exchanger target temperature cannot be obtained.

  Further, when there is a high possibility that the window glass is fogged due to the humidity and temperature in the passenger compartment, or when the window glass is fogged, the electric heat defogger 47 is operated.

  Next, in step S14, the operating state of each solenoid valve 13, 17, 20, 21, 24, which is the refrigerant circuit switching means, is determined according to the operation mode determined in step S6. At this time, in this embodiment, in order to realize a refrigerant circuit according to the cycle, each electromagnetic valve is basically controlled so that the refrigerant flow path through which the refrigerant flows is opened, and the high / low pressure relationship of the refrigerant pressure is determined. For the refrigerant flow path through which the refrigerant does not flow, each solenoid valve is set in a non-energized state to suppress power consumption.

  Details of step S14 will be described with reference to the flowchart of FIG. First, in step S141, the operation mode determined in step S6 is read into the memory CYCLE_VALVE. Next, in step S142, it is determined whether or not the vehicle air conditioner 1 is stopped, that is, whether or not the vehicle interior is not air-conditioned.

  If it is determined in step S142 that the vehicle air conditioner 1 is stopped, the memory CYCLE_VALVE is set to the cooling mode (COOL cycle) in step S143, and the process proceeds to step S144. If it is determined in step S143 that the vehicle air conditioner 1 has not stopped, the process proceeds to step S144.

  In step S144, the operating state of each solenoid valve 13, 17, 20, 21, 24 is determined. Specifically, when the memory CYCLE_VALVE is set to the cooling mode (COOL cycle), all the solenoid valves are deenergized. When the memory CYCLE_VALVE is set to the heating mode (HOT cycle), the electric three-way valve 13, the high-pressure solenoid valve 20, and the low-pressure solenoid valve 17 are energized, and the remaining solenoid valves 21 and 24 are de-energized. And Further, when the memory CYCLE_VALVE is set to the first dehumidification mode (DRY_EVA cycle), the electric three-way valve 13, the low pressure solenoid valve 17, the dehumidification solenoid valve 24, and the heat exchanger shut-off solenoid valve 21 are energized, and the high pressure The solenoid valve 20 is turned off. In addition, when the memory CYCLE_VALVE is set to the second dehumidification mode (DRY_ALL cycle), the electric three-way valve 13, the low pressure solenoid valve 17, and the dehumidification solenoid valve 24 are energized, and the remaining solenoid valves 20 and 21 are turned off. Turn on the power.

  That is, in this embodiment, even if it is a case where it switches to the refrigerant circuit of which operation mode, supply of the electric power with respect to at least 1 solenoid valve among each solenoid valve 13, 17, 20, 21, 24 is stopped. It is configured as follows.

  In step S15, whether or not the engine EG is requested to be operated is determined. Here, in an ordinary vehicle that obtains driving force for vehicle travel only from the engine EG, the engine is always operated, so that the engine cooling water is also constantly at a high temperature. Therefore, in a normal vehicle, sufficient heating performance can be exhibited by circulating the engine cooling water to the heater core 36.

  On the other hand, in the hybrid vehicle as in the present embodiment, if there is a margin in the remaining amount of the battery BT, it is possible to travel by obtaining the driving force for traveling only from the traveling electric motor MG. For this reason, even when high heating performance is required, when the engine EG is stopped, the engine coolant temperature only rises to about 40 ° C., and the heater core 36 cannot exhibit sufficient heating performance.

  Therefore, in this embodiment, in order to secure a heat source necessary for heating by the heater core 36, even when high heating performance is required, when the engine coolant temperature Tw is lower than a predetermined reference coolant temperature, A request signal is output from the air conditioning control device 50 to an engine control device (not shown) used for controlling the engine EG so as to operate the engine EG.

  As a result, the engine coolant temperature Tw is increased to obtain high heating performance. Such an operation request signal for the engine EG causes the engine EG to operate even when it is not necessary to operate the engine EG as a driving source for vehicle travel. Become. For this reason, it is desirable to reduce the frequency of outputting the operation request signal of the engine EG as much as possible.

  In step S <b> 16, defrost control of the outdoor heat exchanger 16 is performed when frost formation has occurred in the outdoor heat exchanger 16. Here, when the refrigerant evaporating temperature in the outdoor heat exchanger 16 is lowered to about −12 ° C. when causing the refrigerant to exert an endothermic effect in the outdoor heat exchanger 16 as in the heating mode refrigerant circuit, the outdoor heat exchange is performed. It is known that frosting occurs in the vessel 16.

  When such frost formation occurs, outdoor air cannot flow through the outdoor heat exchanger 16, and heat cannot be exchanged between the refrigerant and the outdoor air in the outdoor heat exchanger 16. For this reason, when frost formation occurs in the outdoor heat exchanger 16, a control process for forcibly setting the cooling mode is performed. As will be described later, in the cooling mode refrigerant circuit, the high-temperature refrigerant radiates heat in the outdoor heat exchanger 16, so that frost generated in the outdoor heat exchanger 16 can be melted. Therefore, the cooling mode can also be expressed as a defrost cycle.

  In step S17, various devices 61, 13, 17, 20, 21, 24, 16a, 32, 62, 63, 64 are provided from the air conditioning control device 50 so that the control state determined in the above-described steps S6 to S16 is obtained. Control signal and control voltage are output. For example, a control signal is output to the inverter 61 for the electric motor 11b of the compressor 11 so that the rotational speed of the compressor 11 becomes the rotational speed determined in step S11.

  In the next step S18, the process waits for the control period τ, and returns to step S3 when it is determined that the control period τ has elapsed. In the present embodiment, the control cycle τ is 250 ms. This is because the air conditioning control in the passenger compartment does not adversely affect the controllability even if the control period is slower than the engine control or the like. Furthermore, it is possible to suppress a communication amount for air conditioning control in the vehicle and to sufficiently secure a communication amount of a control system that needs to perform high-speed control such as engine control.

  Next, the more detailed content of the frost formation determination process in above-mentioned step S16 is demonstrated. FIG. 9 is a flowchart showing the main part of step S16.

  First, in steps S20 to S22, a frost determination value that is a determination reference value for frost determination is set. In this example, different frost determination values are set when the engine EG is operating and when it is stopped.

  Specifically, in step S20, it is determined whether or not the engine EG is operating (engine ON). If the engine EG is stopped (NO determination), the process proceeds to step S21, and the frost determination value is set. On the other hand, when the engine EG is operating (in the case of YES determination), the process proceeds to step S22, and the frost determination value is set to a value higher than the first reference temperature. Set to 2 reference temperatures (-11 ° C in this example).

  After setting the frost determination value in steps S21 and S22, the process proceeds to step S23, and it is determined whether or not the outdoor heat exchanger 16 has been frosted. In this example, it is determined whether or not the refrigerant intake temperature detected by the intake temperature sensor 57 is lower than the frost determination value.

  When the refrigerant suction temperature is lower than the frost determination value (in the case of YES determination), it is determined that frost formation has occurred in the outdoor heat exchanger 16, and the process proceeds to step S24. In step S24, it is determined whether or not the defrost flag is 0. When it is determined that the defrost flag is 0 (in the case of YES determination), after setting the defrost count in steps S25 to S27. In step S28, the defrost flag is set to 1.

  Here, the defrost flag is a flag for identifying whether or not the defrost mode is selected, and is set to 1 when the defrost mode is selected, and is set to 0 when the defrost mode is not selected. The defrost count represents the remaining time of the defrost mode execution time. In this example, since the flowchart of FIG. 9 is executed at a cycle of 0.25 seconds, one defrost count corresponds to 0.25 seconds of the remaining time of the defrost mode.

  In this example, in steps S25 to S27, different defrost counts are set when the outside air temperature is higher than the predetermined temperature and when it is equal to or lower than the predetermined temperature. Specifically, in step S25, it is determined whether or not the outside air temperature is higher than a predetermined temperature (0 ° C. in this example). If the outside air temperature is equal to or lower than the predetermined temperature (NO determination), step S26 is performed. Then, the defrosting count is set to the first count number (2400 count = 10 minutes in this example). On the other hand, if the outside air temperature is higher than the predetermined temperature in step S25 (in the case of YES determination), the process proceeds to step S27, and the defrost count is set to a second count number smaller than the first count number (1200 count = 5 in this example). Minutes). As a result, the defrosting mode is performed for a longer time when the outside air temperature is likely to form frost.

  As in steps S20 to S22 described above, the frosting determination value is set higher during engine operation when the engine coolant temperature is raised than when the engine is stopped when the engine coolant temperature is not raised. It becomes easier to enter the defrosting mode compared to when stopped.

  When it is determined in step S23 that the refrigerant suction temperature is higher than the frost determination value (in the case of NO determination), or when the defrost flag is already set to 1 in step S23 (in the case of NO determination). In step S29, the process proceeds to step S29.

  In step S29, it is determined whether the defrost count is greater than 0 (defrost count> 0). When the defrost count is 0 or less (in the case of NO determination), it is determined whether the defrost mode is not originally set, or whether the defrost mode is set but the defrost count is 0. In step S30, the defrost flag is set to zero. Thereby, modes other than defrosting (modes other than defrosting mode) will be selected.

  On the other hand, when the defrost count is larger than 0 in step S29 (in the case of YES determination), the process proceeds to step S31, and the defrost count is decreased by 1 (defrost count = defrost count-1).

  Subsequently, in step S32, it is determined whether or not the defrosting is completed. In this example, when the refrigerant suction temperature is higher than a predetermined temperature (for example, 10 ° C.) (in the case of YES determination), it is determined that the defrosting is completed and the process proceeds to step S33. In step S33, the defrost count is set to 0 to end the defrost control, and then the process proceeds to step S30 to set the defrost flag to 0.

  On the other hand, when the refrigerant suction temperature is 10 ° C. or lower in step S32 (in the case of NO determination), it is determined that the defrosting is not completed and the process proceeds to step S34 to continue the defrost control (defrost mode). Therefore, the defrost flag is maintained at 1.

  Incidentally, in the control process of FIG. 6, the result of determining that the outdoor heat exchanger 16 is frosted in step S <b> 16 returns to step S <b> 3 after executing steps S <b> 17 and S <b> 18 and performs the cycle / PTC selection process of step S <b> 6. Reflected when executing. Specifically, when the defrost flag is set to 1 in step S16, a cooler cycle is selected in step S6.

  Next, more detailed contents of the cycle / PTC selection process in step S6 will be described. FIG. 10 is a flowchart showing a main part of step S6 in FIG.

  First, in step S40, it is determined whether or not the defrost flag = 1, that is, the defrost mode is set. When the defrost flag is 1 (in the case of YES determination), the process proceeds to steps S41 to S43 to perform defrost control.

  In step S41, it is determined whether or not the blown air having the target blowing temperature TAO can be made with engine cooling water. In this example, when the cooling water temperature is equal to or lower than TAO (in the case of NO determination), it is determined that the blown air at the target blowing temperature TAO cannot be made with the engine cooling water, and the process proceeds to step S42, and the engine EG operation ( Select engine ON) request.

  As a result, if the engine EG is stopped, a request signal is output to start the engine EG to the engine control device in step S15 in FIG. 6, and the engine EG is operated, The temperature of the cooling water can be raised.

  On the other hand, when the cooling water temperature is higher than TAO in step S41 (in the case of YES determination), it is determined that the blown air of the target blowing temperature TAO can be made with engine cooling water, and the process proceeds to step S43, where the cooler cycle is performed. Select (Defrost cycle). As a result, the temperature of the outdoor heat exchanger 16 is increased by the cooler cycle to perform defrosting, and the cold air that has passed through the indoor evaporator 26 is reheated by the heater core 36 that uses engine cooling water as a heat source. Can be blown into the passenger compartment.

  As described above, in steps S40 to S43, even if the defrost flag = 1, that is, the defrost mode is set, the heat pump cycle operation is continued without switching to the cooler cycle until the cooling water temperature rises to TAO, and cooling is performed. When the water temperature exceeds TAO, switching to the cooler cycle is performed, so that it is possible to prevent the cool air from being blown out and the occupant's feeling of warmth being impaired when switching to the cooler cycle for defrosting.

  Further, as in steps S41 and S42, the operation of the engine EG is requested only when the temperature of the engine coolant is equal to or lower than TAO, and the operation of the engine EG is not requested when the temperature of the engine coolant is higher than TAO. When it is not long after the engine EG is stopped, the engine cooling water can be preheated for heating. For this reason, it is possible to reduce fuel consumption by reducing the frequency of engine ON.

  On the other hand, if the defrost flag is not 1 (NO determination) in step 40, that is, if it is not the defrost mode, the process proceeds to step S44 to execute normal cycle selection.

  In step S44, it is determined whether or not the auto outlet is the face (FACE), that is, whether or not the determination of the outlet mode based on TAO (see step S9) is the face mode.

  If it is determined that the auto outlet is a face (in the case of YES determination), the process proceeds to step S43, and a cooler cycle (cooling mode) is selected. That is, as described in step S9, the air outlet mode is determined to be the face mode when the TAO is in a low temperature range. In this case, it is determined that heating by the heat pump cycle is not necessary, and the cooler cycle is performed. Select cooling.

  Incidentally, as described above, the determination of the outlet mode based on TAO is performed in step S9 of FIG. For this reason, when determination of step S44 is performed for the first time, the blower outlet mode (automatic outlet) has not been determined yet. Therefore, when the determination in step S44 is executed for the first time, the processing after step S44 (specifically, the processing from step S44 to step S43, or the processing from step S44 to step S45) is omitted or provisional. Processing such as determination in step S44 is performed in the air outlet mode (initial setting of the air outlet mode).

  If the air outlet mode is not the face mode in step S44 (in the case of NO determination), it is determined that heating is necessary, and the process proceeds to step S45. In step S45, it is determined whether or not there is a margin in the remaining amount of the battery BT (hereinafter referred to as the remaining battery amount). Specifically, it is determined whether or not the remaining battery level is below a margin allowance level that allows for a predetermined margin with respect to the air conditioning trouble level.

  In this example, a value obtained by multiplying the air conditioning failure level by the safety factor 1.2 (air conditioning failure level × 1.2) is used as the margin allowance level. That is, in step S45, when the remaining battery level is less than the value obtained by multiplying the air conditioning failure level by the safety factor 1.2 (air conditioning failure level × 1.2) (in the case of YES determination), the remaining battery level is determined. It is determined that there is no room, and the process proceeds to step S46.

  Here, the air-conditioning trouble level means that the remaining battery level is so low that air-conditioning troubles occur. In this example, the air-conditioning trouble level is set in advance based on vehicle specifications and the like. When the remaining battery level reaches the air conditioning hindrance level, the supply of air conditioning power is limited (reduced) during vehicle acceleration when a large amount of vehicle travel power is required, and air conditioning is hindered.

  Any appropriate method can be used as a method for detecting the remaining battery level. For example, the battery remaining amount may be obtained based on information such as the charging current, charging time, discharging current, discharging time, etc. of the battery BT, or the battery remaining amount may be obtained from the specific gravity of the electrolyte of the battery BT. Also good. Further, simply, the voltage of the battery BT may be used as the remaining battery level.

  In step S46, a request for engine EG operation (engine ON) is selected to select heating with low power consumption, that is, heating using engine cooling water as a heat source. As a result, if the engine EG is stopped, a request signal is output to start the engine EG to the engine control device in step S15 in FIG. 6, and the engine EG is operated, The temperature of the cooling water can be raised.

  Subsequently, in step S47, it is determined whether or not the blown air having the target blowing temperature TAO can be made with engine cooling water. In this example, when the cooling water temperature is higher than TAO (in the case of YES determination), it is determined that the blown air at the target blowing temperature TAO can be made with the engine cooling water, and the process proceeds to step S43, where the cooler cycle (cooling) Mode). Thereby, the cold air after passing through the indoor evaporator 26 can be reheated by the heater core 36 using the engine cooling water as a heat source to be blown into the passenger compartment.

  On the other hand, when it is determined in step S45 that the remaining battery capacity is sufficient (in the case of NO determination), or in step S47, it is determined that the blown air at the target outlet temperature TAO cannot be made with engine cooling water. In the case (in the case of NO determination), the process proceeds to step S48 and subsequent steps to select heating by the heat pump cycle.

  In step S48 and subsequent steps, one of a HOT cycle, a DRY_EVA cycle, and a DRY_ALL cycle (a heating mode, a first dehumidifying mode, and a second dehumidifying mode) is selected according to the necessity of dehumidification.

  In step S48, whether there is a possibility of window fogging is determined based on the relative humidity RHW of the window glass surface. In this example, it is determined whether or not RHW is higher than 100. If RHW is higher than 100 (in the case of YES determination), it is determined that there is a possibility of window fogging and the process proceeds to step S49.

  In step S49, the necessity level (necessity) of dehumidification is determined based on the evaporator blown air temperature Te, and depending on the determination result, the heating mode, the first dehumidification mode, and the second dehumidification mode are determined in steps S50 to S52. Choose one.

  Specifically, when the evaporator outlet air temperature Te is high, it is determined that dehumidification is necessary (the degree of necessity is high), and a DRY_EVA cycle (first dehumidification mode) having a high dehumidifying capacity is selected (step S50). ). If the evaporator blown air temperature Te is low, it is determined that there is no need for dehumidification, and a HOT cycle (heating mode) having no dehumidifying capacity but high heating capacity is selected (step S52). When the evaporator blowing air temperature Te is medium, it is determined that the degree of dehumidification is small, and the DRY_ALL cycle (first dehumidification mode) having a small dehumidifying capacity is selected (step S51).

  In this example, the necessity degree of dehumidification is determined based on the evaporator blowing air temperature Te and the map shown in step S49 of FIG. By selecting the operation mode using the map, the temperature of the indoor evaporator 26 is controlled to approximately 2 ° C.

  On the other hand, if RHW is 100 or less in step S48 (in the case of NO determination), it is determined that there is no possibility of window fogging and the process proceeds to step S52, where there is no dehumidification capacity but a high heating capacity HOT cycle (heating) Mode).

  Since the vehicle air conditioner 1 of this embodiment is controlled as described above, it operates as follows according to the operation mode selected in the control step S6.

(A) Cooling mode (COOL cycle: see FIG. 1)
In the cooling mode, the air-conditioning control device 50 deenergizes all the solenoid valves, so that the electric three-way valve 13 is located between the refrigerant outlet side of the indoor condenser 12 and one refrigerant inlet / outlet of the first three-way joint 15. , The low pressure solenoid valve 17 is closed, the high pressure solenoid valve 20 is opened, the heat exchanger shut-off solenoid valve 21 is opened, and the dehumidifying solenoid valve 24 is closed.

  Thereby, as shown by the arrow in FIG. 1, the compressor 11 → the indoor condenser 12 → the electric three-way valve 13 → the first three-way joint 15 → the outdoor heat exchanger 16 → the second three-way joint 19 → the high-pressure solenoid valve 20 → Second check valve 22 → Variable throttle mechanism 27b of temperature type expansion valve 27 → Fourth three-way joint 25 → Indoor evaporator 26 → Temperature sensitive part 27a of temperature type expansion valve 27 → Fifth three way joint 28 → Accumulator 29 → A vapor compression refrigeration cycle in which the refrigerant circulates in the order of the compressor 11 is configured.

  In this cooling mode refrigerant circuit, the refrigerant flowing into the first three-way joint 15 from the electric three-way valve 13 does not flow out to the low-pressure solenoid valve 17 side because the low-pressure solenoid valve 17 is closed. Further, the refrigerant flowing from the outdoor heat exchanger 16 into the second three-way joint 19 does not flow out to the heat exchanger shut-off electromagnetic valve 21 side because the dehumidifying electromagnetic valve 24 is closed. Further, the refrigerant flowing out from the variable throttle mechanism 27b of the temperature type expansion valve 27 does not flow out to the dehumidifying electromagnetic valve 24 side because the dehumidifying electromagnetic valve 24 is closed. Further, the refrigerant that has flowed into the fifth three-way joint 28 from the temperature sensing portion 27 a of the temperature type expansion valve 27 does not flow out to the second check valve 22 side due to the action of the second check valve 22.

  Accordingly, the high-temperature refrigerant compressed by the compressor 11 is cooled by exchanging heat with the blown air (cold air) that has passed through the indoor evaporator 26 in the indoor condenser 12, and is further cooled by the outdoor heat exchanger 16. It is cooled by exchanging heat with it and expanded under reduced pressure by the temperature type expansion valve 27. The low-pressure refrigerant decompressed by the temperature type expansion valve 27 flows into the indoor evaporator 26 and absorbs heat from the blown air blown from the blower 32 to evaporate. Thereby, the blown air passing through the indoor evaporator 26 is cooled.

  At this time, since the opening degree of the air mix door 38 is adjusted as described above, a part (or all) of the blown air cooled by the indoor evaporator 26 flows into the mixing space 35 from the cold air bypass passage 34, A part (or all) of the blown air cooled by the indoor evaporator 26 flows into the heating cold air passage 33 and passes through the heater core 36, the indoor condenser 12, and the PTC heater 37, and is reheated to be mixed space. 35.

  Thereby, the temperature of the blast air mixed in the mixing space 35 and blown into the vehicle interior is adjusted to a desired temperature, and the vehicle interior can be cooled. In the cooling mode, although the dehumidifying ability of the blown air is high, the heating ability is hardly exhibited.

  The refrigerant flowing out of the indoor evaporator 26 flows into the accumulator 29 through the temperature sensing part 27a of the temperature type expansion valve 27. The gas-phase refrigerant that has been gas-liquid separated by the accumulator 29 is sucked into the compressor 11 and compressed again.

(B) Heating mode (HOT cycle: see FIG. 2)
In the heating mode, the air-conditioning control device 50 energizes the electric three-way valve 13, the high-pressure solenoid valve 20, and the low-pressure solenoid valve 17 and de-energizes the remaining solenoid valves 21, 24. The refrigerant outlet side of the indoor condenser 12 and the refrigerant inlet side of the fixed throttle 14 are connected, the low pressure solenoid valve 17 is opened, the high pressure solenoid valve 20 is closed, and the heat exchanger shut-off solenoid valve 21 is opened. Then, the dehumidifying solenoid valve 24 is closed.

  Thereby, as shown by the arrow in FIG. 2, the compressor 11 → the indoor condenser 12 → the electric three-way valve 13 → the fixed throttle 14 → the third three-way joint 23 → the heat exchanger cutoff electromagnetic valve 21 → the second three-way joint 19. → Vapor compression refrigeration cycle in which refrigerant circulates in the order of outdoor heat exchanger 16 → first three-way joint 15 → low pressure solenoid valve 17 → first check valve 18 → fifth three-way joint 28 → accumulator 29 → compressor 11 Is done.

  In the heating mode refrigerant circuit, the refrigerant flowing into the third three-way joint 23 from the fixed throttle 14 does not flow out to the dehumidifying electromagnetic valve 24 side because the dehumidifying electromagnetic valve 24 is closed. Further, the refrigerant flowing into the second three-way joint 19 from the heat exchanger cutoff electromagnetic valve 21 does not flow out to the high pressure solenoid valve 20 side because the high pressure solenoid valve 20 is closed. The refrigerant flowing into the first three-way joint 15 from the outdoor heat exchanger 16 is connected to the refrigerant outlet side of the indoor condenser 12 and the refrigerant inlet side of the fixed throttle 14 by the electric three-way valve 13. It does not flow out to the electric three-way valve 13 side. The refrigerant flowing from the first check valve 18 into the fifth three-way joint 28 does not flow out to the temperature type expansion valve 27 side because the dehumidifying electromagnetic valve 24 is closed.

  Therefore, the refrigerant compressed by the compressor 11 is cooled by exchanging heat with the blown air blown from the blower 32 by the indoor condenser 12. As a result, the blown air passing through the indoor condenser 12 is heated. At this time, since the opening degree of the air mix door 38 is adjusted, similarly to the cooling mode, the temperature of the blown air mixed in the mixing space 35 and blown into the vehicle interior is adjusted to a desired temperature, Heating can be performed. In the heating mode, the dehumidifying ability of the blown air is not exhibited.

  Further, the refrigerant flowing out of the indoor condenser 12 is decompressed by the fixed throttle 14 and flows into the outdoor heat exchanger 16. The refrigerant that has flowed into the outdoor heat exchanger 16 absorbs heat from the vehicle exterior air blown from the blower fan 16a and evaporates. The refrigerant that has flowed out of the outdoor heat exchanger 16 flows into the accumulator 29 through the low-pressure solenoid valve 17, the first check valve 18, and the like. The gas-phase refrigerant that has been gas-liquid separated by the accumulator 29 is sucked into the compressor 11 and compressed again.

(C) First dehumidification mode (DRY_EVA cycle: see FIG. 3)
In the first dehumidifying mode, the air conditioning control device 50 sets the electric three-way valve 13, the low pressure solenoid valve 17, the heat exchanger shut-off solenoid valve 21 and the dehumidification solenoid valve 24 in the energized state, and sets the high pressure solenoid valve 20 in the non-energized state. The electric three-way valve 13 connects the refrigerant outlet side of the indoor condenser 12 and the refrigerant inlet side of the fixed throttle 14, the low pressure solenoid valve 17 is opened, the high pressure solenoid valve 20 is opened, and heat exchange is performed. The device shut-off solenoid valve 21 is closed, and the dehumidifying solenoid valve 24 is opened.

  Thereby, as shown by the arrow in FIG. 3, the compressor 11, the indoor condenser 12, the electric three-way valve 13, the fixed throttle 14, the third three-way joint 23, the dehumidifying solenoid valve 24, the fourth three-way joint 25, and the indoor evaporation. A vapor compression refrigeration cycle in which the refrigerant circulates in the order of the vessel 26 → the temperature sensing part 27 a of the temperature type expansion valve 27 → the fifth three-way joint 28 → the accumulator 29 → the compressor 11.

  In the refrigerant circuit in the first dehumidifying mode, the refrigerant flowing into the third three-way joint 23 from the fixed throttle 14 flows out to the heat exchanger shut-off solenoid valve 21 side because the heat exchanger shut-off solenoid valve 21 is closed. There is nothing. Further, the refrigerant flowing into the fourth three-way joint 25 from the dehumidifying electromagnetic valve 24 does not flow out toward the variable throttle mechanism 27 b side of the temperature type expansion valve 27 due to the action of the second check valve 22. Further, the refrigerant that has flowed into the fifth three-way joint 28 from the temperature sensing portion 27 a of the temperature type expansion valve 27 does not flow out to the first check valve 18 side due to the action of the first check valve 18.

  Therefore, the refrigerant compressed by the compressor 11 is cooled by exchanging heat with the blown air (cold air) after passing through the indoor evaporator 26 by the indoor condenser 12. As a result, the blown air passing through the indoor condenser 12 is heated. The refrigerant flowing out of the indoor condenser 12 is decompressed by the fixed throttle 14 and flows into the indoor evaporator 26.

  The low-pressure refrigerant flowing into the indoor evaporator 26 absorbs heat from the blown air blown from the blower 32 and evaporates. Thereby, the blown air passing through the indoor evaporator 26 is cooled and dehumidified. Therefore, the blown air cooled and dehumidified by the indoor evaporator 26 is reheated when passing through the heater core 36, the indoor condenser 12, and the PTC heater 37 and blown out from the mixing space 35 into the vehicle interior. That is, dehumidification in the passenger compartment can be performed. In the first dehumidifying mode, the dehumidifying capacity of the blown air can be exhibited, but the heating capacity is small.

  The refrigerant flowing out of the indoor evaporator 26 flows into the accumulator 29 through the temperature sensing part 27a of the temperature type expansion valve 27. The gas-phase refrigerant that has been gas-liquid separated by the accumulator 29 is sucked into the compressor 11 and compressed again.

(D) Second dehumidification mode (DRY_ALL cycle: see FIG. 4)
In the second dehumidifying mode, the air conditioning control device 50 sets the electric three-way valve 13, the low pressure electromagnetic valve 17, and the dehumidifying electromagnetic valve 24 in the energized state and the remaining electromagnetic valves 20 and 21 in the non-energized state. 13 connects between the refrigerant outlet side of the indoor condenser 12 and the refrigerant inlet side of the fixed throttle 14, the low pressure solenoid valve 17 is opened, the high pressure solenoid valve 20 is opened, and the heat exchanger shut-off solenoid valve 21. Is opened, and the dehumidifying electromagnetic valve 24 is opened.

  Thereby, as shown by the arrow in FIG. 4, the compressor 11 → the indoor condenser 12 → the electric three-way valve 13 → the fixed throttle 14 → the third three-way joint 23 → the heat exchanger cutoff electromagnetic valve 21 → the second three-way joint 19. The refrigerant circulates in the order of the outdoor heat exchanger 16 → the first three-way joint 15 → the low pressure solenoid valve 17 → the first check valve 18 → the fifth three-way joint 28 → the accumulator 29 → the compressor 11, and the compressor 11 → Condenser 12 → Electric three-way valve 13 → Fixed throttle 14 → Third three-way joint 23 → Dehumidification solenoid valve 24 → Fourth three-way joint 25 → Indoor evaporator 26 → Temperature sensitive valve 27a of temperature type expansion valve 27 → Fifth three-way A vapor compression refrigeration cycle in which the refrigerant circulates in the order of the joint 28 → accumulator 29 → compressor 11 is configured.

  That is, in the second dehumidifying mode, the refrigerant that has flowed from the fixed throttle 14 into the third three-way joint 23 flows out to both the heat exchanger shut-off solenoid valve 21 side and the dehumidifying solenoid valve 24 side, and from the first check valve 18. Both the refrigerant flowing into the fifth three-way joint 28 and the refrigerant flowing into the fifth three-way joint 28 from the temperature sensing part 27a of the temperature type expansion valve 27 merge at the fifth three-way joint 28 and flow out to the accumulator 29 side.

  In the refrigerant circuit in the second dehumidifying mode, the refrigerant that has flowed from the outdoor heat exchanger 16 into the first three-way joint 15 is such that the electric three-way valve 13 is connected to the refrigerant outlet side of the indoor condenser 12 and the refrigerant inlet of the fixed throttle 14. As a result, the electric three-way valve 13 does not flow out. Further, the refrigerant flowing into the fourth three-way joint 25 from the dehumidifying electromagnetic valve 24 does not flow out toward the variable throttle mechanism 27 b side of the temperature type expansion valve 27 due to the action of the second check valve 22.

  Therefore, the refrigerant compressed by the compressor 11 is cooled by exchanging heat with the blown air (cold air) after passing through the indoor evaporator 26 by the indoor condenser 12. As a result, the blown air passing through the indoor condenser 12 is heated. The refrigerant flowing out of the indoor condenser 12 is depressurized by the fixed throttle 14, branched by the third three-way joint 23, and flows into the outdoor heat exchanger 16 and the indoor evaporator 26.

  The refrigerant that has flowed into the outdoor heat exchanger 16 absorbs heat from the vehicle exterior air blown from the blower fan 16a and evaporates. The refrigerant that has flowed out of the outdoor heat exchanger 16 flows into the fifth three-way joint 28 via the low pressure solenoid valve 17, the first check valve 18, and the like. The low-pressure refrigerant flowing into the indoor evaporator 26 absorbs heat from the blown air blown from the blower 32 and evaporates. Thereby, the blown air passing through the indoor evaporator 26 is cooled and dehumidified.

  Therefore, the blown air cooled and dehumidified by the indoor evaporator 26 is reheated when passing through the heater core 36, the indoor condenser 12, and the PTC heater 37 and blown out from the mixing space 35 into the vehicle interior. At this time, in the second dehumidifying mode, the amount of heat absorbed by the outdoor heat exchanger 16 can be radiated by the indoor condenser 12 as compared to the first dehumidifying mode, so that the blown air is more than in the first dehumidifying mode. Can be heated to high temperatures. That is, in the second dehumidifying mode, it is possible to perform dehumidifying heating that also exhibits a dehumidifying capability while exhibiting a high heating capability.

  The refrigerant that has flowed out of the indoor evaporator 26 flows into the fifth three-way joint 28, merges with the refrigerant that flows out of the outdoor heat exchanger 16, and flows into the accumulator 29. The gas-phase refrigerant that has been gas-liquid separated by the accumulator 29 is sucked into the compressor 11 and compressed again.

  As described above, in this embodiment, it is possible to improve passenger comfort. Specifically, as shown in steps S45 and S46, since the engine ON request is made in advance and the cooling water temperature is raised before the remaining battery level is lowered to the air conditioning trouble level, the remaining battery capacity is lowered to the air conditioning trouble level. Even if the supply of power for air conditioning is restricted and heating by the heat pump cycle becomes impossible, it is possible to immediately shift to heating (hot water heating) using engine cooling water as a heat source. For this reason, since heating can be continued without interruption, passenger comfort can be improved.

  Furthermore, even when an engine ON request is made in step S46, as in steps S47 to S52, when the blown air of the target blowing temperature TAO cannot be made with engine cooling water, the process shifts to hot water heating. Since the heating by the heat pump cycle is continued, it is possible to prevent the cool air from being blown into the passenger compartment by switching to the hot water heating when the cooling water temperature is not sufficiently high. For this reason, a passenger | crew's comfort can be improved more.

  Further, in this embodiment, as in steps S40 to S43, when the engine coolant temperature is low, the engine deactivation control is performed by switching to the defrost cycle (cooler cycle) operation after the engine ON request is made. The outdoor heat exchanger 16 can be defrosted while heating is continued by the heater core 36 using the cooling water as a heat source.

  Further, after the operation of the heat pump cycle is stopped, the defrost control is performed by switching to the operation of the defrost cycle (cooler cycle), so that the outdoor heat exchanger 16 is frosted in a short time when the next heat pump cycle is operated. The possibility of being lost can be reduced.

(Second Embodiment)
In the second embodiment, the cycle selection process related to the defrost control is omitted from the flowchart of FIG. 10 in the first embodiment.

  FIG. 11 is a flowchart showing a main part of step S6 in FIG. First, in step S50 (corresponding to step S44 in FIG. 10), whether or not the auto outlet is the face (FACE), that is, whether or not the determination of the outlet mode based on TAO (see step S9) is the face mode. Determine whether or not.

  When it is determined that the auto outlet is a face (in the case of YES determination), it is determined that heating by the heat pump cycle is not necessary, and the process proceeds to step S51 (corresponding to step S43 in FIG. 10), and the cooler cycle (cooling) Mode). When the air outlet mode is not the face mode (in the case of NO determination), it is determined that heating is necessary, and the process proceeds to step S52 (corresponding to step S45 in FIG. 10), and whether or not there is a margin in the remaining battery level. judge.

  If it is determined that the remaining battery level is not sufficient (in the case of YES determination), the process proceeds to step S53 (corresponding to step S46 in FIG. 10), and the engine EG is operated to select heating using engine cooling water as a heat source. Select (Engine ON) request.

  Subsequently, in step S54 (corresponding to step S47 in FIG. 10), it is determined whether or not the blown air having the target blowing temperature TAO can be made of engine cooling water, and the blowing air having the target blowing temperature TAO is converted to engine cooling water. If it is determined that it can be made (if YES), the process proceeds to step S51 to select a cooler cycle (cooling mode).

  On the other hand, when it is determined in step S52 that the remaining battery capacity is sufficient (in the case of NO determination), it is determined in step S54 that the blown air at the target outlet temperature TAO cannot be made with engine cooling water. In the case (in the case of NO determination), the process proceeds to steps S55 to S59 (corresponding to steps S48 to S52 in FIG. 10) to select heating by the heat pump cycle.

  In steps S55 to S59, one of a HOT cycle, a DRY_EVA cycle, and a DRY_ALL cycle (heating mode, first dehumidification mode, and second dehumidification mode) is selected according to the necessity of dehumidification.

  According to the present embodiment, as in the first embodiment, since the engine ON request is made in advance and the cooling water temperature is raised before the remaining battery level drops to the air conditioning problem level, the remaining battery level is less than the air conditioning problem level. Even if the temperature drops, the heating can be continued without interruption, and the passenger comfort can be improved.

  Further, as in the first embodiment, even when an engine ON request is made, if the blown air at the target blowing temperature TAO cannot be made with engine cooling water, the heat pump does not shift to hot water heating. Since heating by the cycle is continued, it is possible to avoid switching to hot water heating when the cooling water temperature is not sufficiently high and blowing cold air into the passenger compartment, thereby improving passenger comfort. it can.

  In the present embodiment, as in steps S53 → S51, when the engine coolant temperature is low, the engine ON request is made and then the operation is switched to the cooler cycle. Therefore, heating is performed by the heater core 36 using the engine coolant as a heat source. The anti-fogging property of the vehicle window glass can be enhanced by the dehumidifying ability of the cooler cycle while continuing.

  Here, in the heat pump cycle with dehumidification in which dehumidification is performed by the indoor evaporator 26, the indoor evaporator 26 is condensed by absorbing heat from the blown air. And if the condensed water adhering to the indoor evaporator 26 dries after the heat pump cycle is stopped, an unpleasant odor is generated.

  In this respect, in this embodiment, since the switching to the cooler cycle is performed after the heat pump cycle is stopped, it is possible to prevent the condensed water adhering to the indoor evaporator 26 from being dried during the operation of the cooler cycle, and thus an unpleasant odor. Occurrence can be prevented.

(Third embodiment)
The third embodiment relates to cycle selection when a component of the refrigeration cycle 10 (in this example, electromagnetic valves 13, 17, 20, 21, 24) fails.

  FIG. 12 is a flowchart showing the main part of step S6 in FIG. First, in step S70, it is determined whether or not the auto outlet is the face (FACE), that is, whether or not the determination of the outlet mode based on TAO (see step S9) is the face mode.

  If it is determined that the auto outlet is a face (in the case of YES determination), it is determined that heating by the heat pump cycle is not necessary, and the process proceeds to step S71 to select a cooler cycle (cooling mode). When the outlet mode is not the face mode (in the case of NO determination), it is determined that heating is necessary, the process proceeds to step S72, and it is determined whether one or more solenoid valves have failed. Here, the failure of the solenoid valve means a state in which the solenoid valve cannot be turned on due to, for example, a wire of the solenoid valve being cut.

  If it is determined that all the solenoid valves have not failed (in the case of NO determination), the process proceeds to steps S73 to S77 to select heating by the heat pump cycle.

  In steps S73 to S77, one of a HOT cycle, a DRY_EVA cycle, and a DRY_ALL cycle (heating mode, first dehumidification mode, and second dehumidification mode) is selected according to the necessity of dehumidification.

  On the other hand, when it is determined in step S72 that one or more solenoid valves have failed (in the case of YES determination), the process proceeds to step S78, and after determining the engine ON request, the process proceeds to step S71 and the cooler cycle. Select (Cooling mode).

  That is, as shown in step S144 of FIG. 7 described above, since one or more solenoid valves are energized (ON) when setting the heat pump cycle, the heat pump is activated when one or more solenoid valves have failed. The cycle cannot be operated. Specifically, heating by the heat pump cycle or dehumidifying heating becomes impossible.

  For this reason, in this embodiment, when one or more solenoid valves are out of order, heating (hot water heating) can be performed by the heater core 36 using engine cooling water as a heat source by making an engine ON request. it can. As a result, even if the solenoid valve breaks down, heating can be continued without interruption, so that passenger comfort can be improved.

  Further, as shown in step S144 of FIG. 7 described above, all the solenoid valves are set in a non-energized state (OFF) at the time of setting the cooler cycle, so even if one or more solenoid valves are out of order. The operation of the cooler cycle (cooling mode) is possible.

  For this reason, when one or more solenoid valves are out of order, dehumidifying heating can be performed by making an engine ON request and selecting a cooler cycle (cooling mode).

  Incidentally, the failure of the electromagnetic valve includes the failure due to the sticking of the valve in addition to the failure due to the wire breakage of the electromagnetic valve as described above. In the case of a failure of the electromagnetic valve due to the sticking of the valve, the operation of the cooler cycle (cooling mode) becomes impossible, so it is preferable to stop the operation of the refrigeration cycle 10 without selecting the cooler cycle.

(Fourth embodiment)
The fourth embodiment relates to determination of the outlet mode in step S9. Specifically, the switching temperature between the foot (FOOT) mode and the bi-level (B / L) mode is changed according to the target opening degree SW of the air mix door 38 calculated in step S10 of FIG.

  First, the more detailed content of the calculation process of the target opening degree SW of the air mix door 38 in step S10 mentioned above is demonstrated. FIG. 13 is a flowchart showing a main part of step S10 of FIG.

  In step S150, the control water temperature TW is obtained in order to calculate the target opening degree SW of the air mix door 38. In this example, the larger one of the engine cooling water temperature Tw and the indoor condenser target temperature is set as the control water temperature TW.

  Incidentally, the indoor condenser target temperature is basically the same as the above-described heating heat exchanger target temperature, but may be a value obtained by slightly correcting the heating heat exchanger target temperature.

  Subsequently, in step S151, in order to calculate the target opening degree SW of the air mix door 38, a corrected evaporator temperature f1 (corrected evaporator temperature) is calculated. In this example, the corrected evaporator temperature f1 is calculated based on the evaporator temperature Te (evaporator temperature) and the map shown in step S151 of FIG.

  Subsequently, in step S152, the heater temperature is obtained in order to calculate the target opening degree SW of the air mix door 38. The heater temperature is obtained based on the control water temperature TW in step S150 and the corrected evaporator temperature f1 in step S151. In this example, the heater temperature is obtained by the mathematical formula shown in step S152 of FIG. The formula in step S152 is determined through experiments.

  In step S153, the target opening degree SW of the air mix door 38 is calculated based on TAO, the evaporator temperature Te, and the heater temperature.

  In this example, 2 is added to the evaporator temperature Te in the formula shown in step S153 of FIG. 13 (Te + 2), but the value added to the evaporator temperature Te can be changed as appropriate, and the value is not necessarily set to the evaporator temperature Te. There is no need to add.

  Further, in this example, the denominator is not made smaller than 10 in the formula of step S153, but this is to prevent the denominator from becoming too small and the target opening degree SW from becoming too large.

  As can be seen from the mathematical expression in step S153, the target opening SW is determined to be a larger opening (opening on the maximum heating position side) as TAO is higher. Further, as can be seen from the equations in steps S150, S152, and S153, the target opening SW is larger when the engine coolant temperature Tw is lower when the engine coolant temperature Tw is higher than the indoor condenser target temperature ( If the engine coolant temperature Tw is lower than the indoor condenser target temperature, the lower the indoor condenser target temperature, the larger the opening (opening on the maximum heating position side). The Rukoto.

  Next, more detailed contents of the blower outlet mode determination process in step S9 of FIG. 6 will be described. FIG. 14 is a flowchart showing a main part of step S9 of FIG.

  In step S190, it is determined whether the target opening degree SW is close to the maximum heating position (SW = 100%). Specifically, when the target opening degree SW is larger than a predetermined opening degree (95% in this example) (in the case of YES determination), the target opening degree SW is set to the maximum heating position (hereinafter referred to as MAX HOT). It judges that it is near, and progresses to step S191.

  In step S191, the FOOT / B / L switching temperature (predetermined switching temperature) is set to the first predetermined temperature (30 ° C. in this example). The FOOT / B / L switching temperature is the temperature of TAO as a threshold for switching between the foot mode and the bi-level mode.

  On the other hand, when the target opening degree SW is 95% or less in step S190 (in the case of NO determination), it is determined that the target opening degree SW is not close to MAX HOT, and the process proceeds to step S192. In step S192, the FOOT / B / L switching temperature is set to a second predetermined temperature (35 ° C. in this example) higher than the first predetermined temperature.

  And after setting FOOT * B / L switching temperature by step S191, S192, it progresses to step S193 in order to determine a blower outlet mode. In step S193, a blower outlet mode is determined based on TAO and the map shown in step S193 of FIG.

  Incidentally, in the map shown in step S193 of FIG. 14, a hysteresis width of 5 ° C. is set for the switching temperature of the outlet mode in order to prevent control hunting.

  Next, the function and effect of this embodiment will be described. As described above, the heating by the heat pump cycle is selected when, for example, the engine cooling water temperature Tw is low, so that the blown air at the target blowing temperature TAO cannot be made from the engine cooling water.

  During heating by the heat pump cycle, the compressor 11 is driven by the power for air conditioning supplied from the battery BT. Therefore, at the time of heating by the heat pump cycle, it is desirable to reduce the power consumption by making the target temperature of the indoor condenser 12 as low as possible (as close as possible to the target blowing temperature TAO).

  However, since the blowout temperature tends to be low when the target temperature of the indoor condenser 12 is low, the blowout temperature is set so that the target opening degree SW of the air mix door 38 becomes the opening degree on the MAX HOT side as the target temperature of the indoor condenser 12 is low. It is desirable to suppress the decrease in the above.

  That is, when heating by the heat pump cycle, when trying to achieve both reduction of power consumption and securing of the blowing temperature, the target opening degree SW of the air mix door 38 is frequently close to MAX HOT even if TAO is not so high. Will be.

  In the present embodiment, as described above, the target temperature of the indoor condenser 12 is basically set to the same value as that of TAO, and the target opening degree SW of the air mix door 38 is increased as the indoor condenser target temperature is lower. Is determined. For this reason, in the present embodiment, while it is possible to achieve both reduction of power consumption and securing of the blowing temperature, the frequency of the target opening degree SW of the air mix door 38 near the MAX HOT even if TAO is not so high. Get higher.

  On the other hand, in the present embodiment, as shown in FIGS. 1 to 4, the face air outlet 41 is arranged at a position near the cold air bypass passage 34 in order to realize the cabin air temperature distribution of the cold head heat, and the foot air outlet 42. Is arranged at a position closer to the cooling air passage 33 for heating, and the blowing temperature from the face blowing port 41 is made lower than the blowing temperature from the foot blowing port 42.

  However, when the air mix door 38 is in the vicinity of MAX HOT, the air volume in the cold air bypass passage 34 becomes very small, so that the air outlet temperature from the face outlet 41 becomes as high as the air outlet temperature from the foot outlet 42. Therefore, there is a problem that the occupant becomes uncomfortable, for example, it is easy for the occupant's face to be hot.

  In particular, in the present embodiment, as described above, when heating by the heat pump cycle, the frequency of the air mix door 38 being close to MAX HOT increases. Therefore, the bi-level mode is selected when the air mix door 38 is close to MAX HOT. If the face outlet 41 is opened, this problem becomes remarkable.

  In view of this point, in this embodiment, when the target opening degree SW of the air mix door 38 is the opening degree on the MAX HOT side with respect to the predetermined opening degree as in steps S190 to S193 (in this example, more than 95%). When the target opening degree SW of the air mix door 38 is larger than the predetermined opening degree than the MAX HOT (when it is smaller than 95% in this example), the FOOT · Since the B / L switching temperature is set low, when the air mix door 38 is in the vicinity of MAX HOT, the bi-level mode in which the face outlet 41 is opened can be made difficult. In other words, it is possible to easily enter a foot mode in which the face outlet 41 is closed.

  For this reason, since it can suppress that warm air blows off from the face blower outlet 41 when the air mix door 38 exists in MAX HOT vicinity, a passenger | crew's comfort can be improved.

(Fifth embodiment)
In the fourth embodiment, hot air is prevented from being blown out from the face outlet 41 during heating by the heat pump cycle. However, in the fifth embodiment, when the cooling water temperature is relatively low (for example, 35 to 40 ° C.). In the case of the degree, hot air is prevented from being blown out from the face outlet 41.

  FIG. 15 is a flowchart showing a main part of step S9 of FIG. The flowchart of FIG. 15 is obtained by changing step S190 of the flowchart of FIG. 14 to step S200, and other steps are the same as those of the flowchart of FIG.

  In step S200, it is determined whether or not the cooling water temperature is relatively low. In this example, when the temperature difference between the cooling water temperature and TAO is smaller than 3 ° C. (in the case of YES determination), it is determined that the cooling water temperature is relatively low, and the process proceeds to step S201 (corresponding to step S191 in FIG. 14). move on.

  In step S201, the FOOT / B / L switching temperature is set to a first predetermined temperature (30 ° C. in this example).

  On the other hand, when the temperature difference between the cooling water temperature and TAO is 3 ° C. or more in step S200 (in the case of NO determination), it is determined that the cooling water temperature is high, and the process proceeds to step S202 (corresponding to step S192 in FIG. 14). move on.

  In step S202, the FOOT / B / L switching temperature is set to a second predetermined temperature (35 ° C. in this example) higher than the first predetermined temperature.

  Then, after the FOOT / B / L switching temperature is set in steps S201 and S202, the process proceeds to step S203 (corresponding to step S193 in FIG. 14) to determine the outlet mode. In step S203, a blower outlet mode is determined based on TAO and the map shown in step S203 of FIG.

  Next, the function and effect of this embodiment will be described. The engine coolant temperature Tw is as high as, for example, about 80 ° C. when the engine EG is constantly operated, but is about 35 to 40 ° C. when the operation of the engine EG is intermittent. It may be only low temperature.

  As can be seen from the equations in steps S150, S152, and S153 of FIG. 13, when the engine coolant temperature Tw is only about 35 to 40 ° C., the engine coolant temperature Tw is about 80 ° C. Compared to the case, the target opening degree SW of the air mix door 38 becomes a large opening degree (MAX HOT side opening degree).

  That is, when the engine coolant temperature Tw is low, the target opening degree SW of the air mix door 38 becomes close to MAX HOT even if TAO is not so high. Therefore, similarly to the fourth embodiment, the problem that the occupant becomes uncomfortable, such as the flaming of the occupant's face, is likely to occur.

  In view of this point, in this embodiment, when the engine coolant temperature Tw is lower than a predetermined temperature as in steps S200 to S203 (in this example, the temperature difference between the coolant temperature and TAO is smaller than 3 ° C. ) When the engine coolant temperature Tw is higher than a predetermined temperature (in this example, when the temperature difference between the coolant temperature and TAO is greater than 3 ° C.), the FOOT / B / L switching Since the temperature is set low, when the air mix door 38 is in the vicinity of MAX HOT, the bi-level mode in which the face air outlet 41 is opened can be prevented. In other words, it is possible to easily enter a foot mode in which the face outlet 41 is closed.

  For this reason, since it can suppress that warm air blows off from the face blower outlet 41 when the air mix door 38 exists in MAX HOT vicinity, a passenger | crew's comfort can be improved.

(Other embodiments)
In addition, the above-mentioned 1st-5th embodiment is only what demonstrated one specific example of the control processing of the vehicle air conditioner in this invention, A various deformation | transformation is possible without being limited to this.

  For example, the value of the expected margin level in step S45 of the first embodiment and step S52 of the second embodiment can be changed as appropriate.

  For example, step S47 in the first embodiment may be omitted. That is, if an engine ON request is made in step S46, the process may unconditionally proceed to step S43 to select a cooler cycle.

  For example, in step S72 of the third embodiment, it is determined whether or not the solenoid valve has failed. However, it is determined whether or not the components of the refrigeration cycle 10 other than the solenoid valve have failed. May be.

  For example, in step S190 of the fourth embodiment, the value of the predetermined opening compared with the target opening SW can be changed as appropriate.

  For example, in steps S191 and S192 of the fourth embodiment and steps S201 and S202 of the fifth embodiment, the set value of the FOOT / B / L switching temperature can be appropriately changed.

  For example, in step S200 of the fifth embodiment, the method for determining whether or not the coolant temperature is relatively low can be changed as appropriate.

  Moreover, although each said embodiment demonstrated the example which applied the vehicle air conditioner of this invention to the hybrid vehicle, the application object of this invention is not limited to a hybrid vehicle, For example, by stopping an engine. The present invention can be applied to various vehicles such as a vehicle that saves fuel.

10 Vapor compression refrigeration cycle 11 Compressor 12 Indoor condenser 13 Electric three-way valve (solenoid valve)
16 Outdoor heat exchanger 17 Low pressure solenoid valve (solenoid valve)
20 High pressure solenoid valve (solenoid valve)
21 Heat exchanger shut-off solenoid valve (solenoid valve)
24 Dehumidification solenoid valve (solenoid valve)
26 Indoor evaporator 31 Casing 36 Heater core (hot water heating means, heat exchanger for heating)
38 Air mix door (temperature adjustment means)
41 Face outlet 42 Foot outlet 41a Face door (air outlet mode switching means)
42a Foot door (air outlet mode switching means)
50 Air-conditioning control device (control means)
BT battery EG engine (internal combustion engine)
MG Electric motor for traveling

Claims (3)

A vapor compression refrigeration cycle (12) having an indoor condenser (12) for exchanging heat between the blown air blown into the vehicle interior and the refrigerant, and constituting a heat pump cycle for heating the blown air with the indoor condenser (12) 10) and
A casing (31) for housing the indoor condenser (12);
A cooling cold air passage (33) formed in the casing (31), and the blown air flows through the indoor condenser (12);
A cold air bypass passage (34) formed in the casing (31) and through which the blown air flows bypassing the indoor condenser (12);
Temperature adjusting means (38) for adjusting the temperature of the blown air by changing the air volume ratio between the blown air flowing through the cold air passage (33) for heating and the blown air flowing through the cold wind bypass passage (34); ,
A face outlet (41) that blows out the conditioned air toward the upper body of a passenger in the passenger compartment, the blown air that is formed in the casing (31) and temperature-adjusted by the temperature adjusting means (38);
A foot outlet (42) that is formed in the casing (31) and blows out the conditioned air toward the feet of the occupant with the blown air temperature-adjusted by the temperature adjusting means (38);
An air outlet that switches between a bi-level mode that opens both the face air outlet (41) and the foot air outlet (42) and a foot mode that closes the face air outlet (41) and opens the foot air outlet (42). Mode switching means (41a, 42a);
Control means (50) for determining the target opening degree of the temperature adjusting means (38) and determining the switching between the bi-level mode and the foot mode,
When the temperature adjusting means (38) fully opens the heating cold air passage (33) and fully closes the cold air bypass passage (34) as a maximum heating position,
The control means (50)
Determining the target temperature of the indoor condenser (12) based on the target blowing temperature;
As the target temperature of the indoor condenser (12) is lower, the target opening of the temperature adjusting means (38) is determined as the opening on the maximum heating position side,
When the target blowing temperature is higher than a predetermined switching temperature, select the foot mode,
When the target blowing temperature is lower than the predetermined switching temperature, the bi-level mode is selected,
When the target opening of the temperature adjusting means (38) is the opening on the maximum heating position side with respect to the predetermined opening, the target opening of the temperature adjusting means (38) is more than the predetermined opening. The vehicle air conditioner is characterized in that the predetermined switching temperature is set lower than when the opening is on the side opposite to the position. A heat exchanger (36) for heating that heats the blown air blown into the passenger compartment by exchanging heat with cooling water of the internal combustion engine (EG);
A casing (31) containing the heating heat exchanger (36);
A cooling cold air passage (33) formed in the casing (31), and the blast air flows through the heating heat exchanger (36);
A cold air bypass passage (34) formed in the casing (31) and through which the blown air flows by bypassing the heating heat exchanger (36);
Temperature adjusting means (38) for adjusting the temperature of the blown air by changing the air volume ratio between the blown air flowing through the cold air passage (33) for heating and the blown air flowing through the cold wind bypass passage (34); ,
A face outlet (41) that blows out the conditioned air toward the upper body of a passenger in the passenger compartment, the blown air that is formed in the casing (31) and temperature-adjusted by the temperature adjusting means (38);
A foot outlet (42) that is formed in the casing (31) and blows out the conditioned air toward the feet of the occupant with the blown air temperature-adjusted by the temperature adjusting means (38);
An air outlet that switches between a bi-level mode that opens both the face air outlet (41) and the foot air outlet (42) and a foot mode that closes the face air outlet (41) and opens the foot air outlet (42). Mode switching means (41a, 42a);
Control means (50) for determining the target opening degree of the temperature adjusting means (38) and determining the switching between the bi-level mode and the foot mode,
When the temperature adjusting means (38) fully opens the heating cold air passage (33) and fully closes the cold air bypass passage (34) as a maximum heating position,
The control means (50)
As the temperature of the cooling water is lower, the target opening of the temperature adjusting means (38) is determined as the opening on the maximum heating position side,
When the target blowing temperature is higher than a predetermined switching temperature, select the foot mode,
When the target blowing temperature is lower than the predetermined switching temperature, the bi-level mode is selected,
The vehicle air conditioner is characterized in that when the temperature of the cooling water is lower than a predetermined temperature, the predetermined switching temperature is set lower than when the temperature of the cooling water is higher than the predetermined temperature. The vapor compression refrigeration cycle (10) has a compressor (11) for compressing and discharging a refrigerant,
In the heating cold air passage (33), hot water heating means (36) for heating the blown air using cooling water of the internal combustion engine (EG) as a heat source is disposed,
The control means (50) outputs an operation request signal to the internal combustion engine (EG) when it is determined that a component of the vapor compression refrigeration cycle (10) has failed. Item 2. The vehicle air conditioner according to Item 1.

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