JP2011011642A - Vehicular air conditioning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress uncomfortable odor generated in a refrigeration cycle applied to a vehicular air conditioning device, and reduce the power consumption of a compressor of a refrigeration cycle.SOLUTION: A refrigerant circuit is switched from a dehumidification/heating mode to a heating mode when a deviation TEO-Te between a target blowing air temperature TEO of blowing air from an indoor evaporator 26 and a refrigerant evaporation temperature Te of the indoor evaporator 26 becomes equal to or more than a first reference temperature difference, and the refrigerant circuit is switched from the heating mode to the dehumidification/heating mode when the deviation TEO-Te becomes equal to or less than a second reference temperature difference. Accordingly, when the deviation TEO-Te becomes equal to or more than the first reference temperature difference and the refrigerant evaporation temperature Te need not be reduced any more, the power consumption of the compressor 11 is reduced. Additionally, when the deviation TEO-Te becomes equal to or less than the second reference temperature difference, the refrigerant evaporation temperature Te is reduced again to prevent the uncomfortable odor generated by evaporation of dew condensation of the indoor evaporator 26.

Description

  The present invention relates to a vehicle air conditioner including a refrigeration cycle.

  2. Description of the Related Art Conventionally, there is known a vehicle air conditioner that performs temperature adjustment and humidity adjustment of blown air blown into a vehicle interior by a vapor compression refrigeration cycle. In this type of vehicle air conditioner, an unpleasant odor is generated when the condensed water condensed in the indoor evaporator of the refrigeration cycle dries or the condensed water freezes. There was a problem of discomforting.

  On the other hand, in the vehicle air conditioner described in Patent Document 1, after the compressor of the refrigeration cycle is stopped, the compressor is restarted before the condensed water generated in the indoor evaporator starts to dry. The refrigerant evaporation temperature of the evaporator is set below the dew point of the blown air. Thereby, generation | occurrence | production of unpleasant odor is suppressed so that condensed water may not be dried.

  Moreover, in the vehicle air conditioner described in Patent Document 2, the refrigerant discharge temperature of the compressor is controlled based on the refrigerant pressure in the cycle at the start of the refrigeration cycle, so that the refrigerant evaporation temperature of the indoor evaporator is dew condensation water. This prevents the freezing temperature (0 ° C.) or lower. Thereby, freezing of dew condensation water is prevented and generation | occurrence | production of an unpleasant odor is suppressed.

  Patent Document 3 discloses a cooling mode refrigerant circuit that radiates heat absorbed by an indoor evaporator of a refrigeration cycle by an outdoor condenser and cools blown air blown into the vehicle interior, and a room of the refrigeration cycle. Disclosed is a vehicle air conditioner configured to be able to switch between a refrigerant circuit in a dehumidifying and heating mode in which the amount of heat absorbed by both the evaporator and the outdoor heat exchanger is radiated by an indoor condenser to dehumidify and heat the blown air. Has been.

JP 2001-130247 A JP 2008-13165 A JP 7-32871 A

  However, the means for suppressing the generation of unpleasant odor caused by the dew condensation water described in Patent Documents 1 and 2, that is, the refrigerant evaporation temperature in the indoor evaporator is below the dew point of the blown air and above the freezing temperature (0 ° C.). When the means described above is applied to the dehumidifying and heating mode of the vehicle air conditioner of Patent Document 3, the following problems arise.

  That is, in the vehicle air conditioner of Patent Document 3, the operation mode is mainly switched according to the outside air temperature, and the mode is switched to the dehumidifying heating mode when the outside air temperature is low. Therefore, in order for the refrigerant to exert an endothermic effect in both the indoor evaporator and the outdoor heat exchanger in the dehumidifying heating mode, the refrigerant evaporation temperature in both heat exchangers must be lower than the outside air temperature.

  For this reason, if the means for suppressing the generation of unpleasant odors described in Patent Documents 1 and 2 in the dehumidifying heating mode is adopted, the refrigerant evaporation temperature in the indoor evaporator and the outdoor heat exchanger is consequently reduced. There is a problem that the power consumption of the compressor becomes large because the freezing temperature (0 ° C.) lower than the air temperature must be lowered.

  In view of the above points, an object of the present invention is to achieve both suppression of generation of unpleasant odor and reduction of power consumption of a compressor in a vehicle air conditioner including a refrigeration cycle.

  In order to achieve the above object, according to the first aspect of the present invention, a compressor (11) that sucks, compresses and discharges a refrigerant, an outdoor heat exchanger (16) that exchanges heat between the refrigerant and outdoor air, and a refrigerant And an indoor evaporator (26) for exchanging heat between the air blown into the passenger compartment and evaporating the refrigerant, and an indoor condenser (12) for heating the air by exchanging heat between the refrigerant and the blown air. A vapor compression refrigeration cycle (10), target blowing temperature determining means (S113, S120) for determining a target blowing air temperature (TEO) of blown air blown from the indoor evaporator (26), and an indoor evaporator ( 26) an evaporator temperature detecting means (56) for detecting the refrigerant evaporation temperature (Te), and the refrigeration cycle (10) converts the heat absorbed by the outdoor heat exchanger (16) into the indoor condenser (12). Dissipate heat and blow air The refrigerant circuit in the heating mode that heats the air and the amount of heat absorbed by both the indoor evaporator (26) and the outdoor heat exchanger (16) are radiated by the indoor condenser (12) to dehumidify the blown air. Refrigerant circuit switching means (13, 17, 20, 21, 24) for switching the refrigerant circuit in the dehumidifying and heating mode to be heated is provided, and the refrigerant circuit switching means (13 to 24) evaporates the refrigerant from the target blown air temperature (TEO). When the deviation (TEO-Te) obtained by subtracting the temperature (Te) is equal to or greater than a predetermined first reference temperature difference, the refrigerant circuit is switched from the dehumidifying heating mode to the heating mode, and the deviation (TEO-Te) is predetermined. The vehicle air conditioner is switched from the heating mode to the dehumidifying heating mode when the temperature becomes equal to or less than the second reference temperature difference.

  According to this, since the refrigerant circuit is switched from the dehumidifying heating mode to the heating mode when the deviation (TEO-Te) becomes equal to or greater than the first reference temperature difference, the power consumption of the compressor (11) can be reduced. That is, when the deviation (TEO-Te) is equal to or greater than the first reference temperature difference, the refrigerant evaporation temperature (Te) of the indoor evaporator (26) is sufficiently lowered, and thus the refrigerant evaporation temperature (Te) is further exceeded. There is no need to reduce

  Therefore, the power consumption of the compressor (11) for reducing the pressure of the refrigerant flowing through the indoor evaporator (26) by switching to the heating mode refrigerant circuit that does not exhibit the endothermic effect in the indoor evaporator (26). Can be reduced.

  Furthermore, since the refrigerant circuit is switched from the heating mode to the dehumidifying heating mode when the deviation (TEO-Te) becomes equal to or less than the second reference temperature difference, the air conditioning feeling of the occupant is deteriorated and an unpleasant odor is generated. Nor. That is, when the deviation (TEO−Te) becomes equal to or smaller than the second reference temperature difference, the refrigerant evaporation temperature (Te) of the indoor evaporator (26) may rise and exceed the target blowing air temperature (TEO).

  Therefore, by switching to the refrigerant circuit in the dehumidifying and heating mode in which the indoor evaporator (26) exhibits an endothermic effect, the refrigerant evaporation temperature (Te) of the indoor evaporator (26) is lowered again to dehumidify the blown air. At the same time, it is possible to prevent the condensed water condensed in the indoor evaporator (26) from drying out. As a result, according to the present invention, it is possible to achieve both suppression of generation of unpleasant odor and reduction of power consumption of the compressor (11).

  According to a second aspect of the present invention, in the vehicle air conditioner according to the first aspect, the refrigerant circuit switching means (13 to 24) further converts the amount of heat absorbed by the indoor evaporator (26) to the outdoor heat exchanger. The target determined when the refrigerant circuit switching means (13 to 24) switches to the refrigerant circuit in the dehumidifying heating mode, having a function of switching to the cooling mode refrigerant circuit that radiates heat and cools the blown air in (16). The blown air temperature (TEO) is set to be lower than the target blown air temperature (TEO) determined when switching to the cooling mode refrigerant circuit.

  Here, in the refrigerant circuit in the dehumidifying and heating mode in which the endothermic effect is exhibited in the indoor evaporator (26), it is necessary to circulate the refrigerant in the indoor evaporator (26), but the endothermic effect in the indoor evaporator (26). In the refrigerant circuit in the heating mode that does not exhibit the effect, it is not necessary to circulate the refrigerant in the indoor evaporator (26). Accordingly, the flow rate of the refrigerant flowing through the indoor evaporator (26) varies greatly between the refrigerant circuit in the dehumidifying heating mode and the refrigerant circuit in the heating mode.

  For this reason, in the transition period immediately after switching between the refrigerant circuit in the dehumidifying heating mode and the refrigerant circuit in the heating mode, a temperature distribution tends to occur in the indoor evaporator (26). Therefore, in the portion of the indoor evaporator (26) where the temperature is high, the temperature of the indoor evaporator (26) exceeds the dew point of the dew condensation water, which may cause an unpleasant odor.

  On the other hand, in this invention, the target blowing air temperature (TEO) determined when switching to the refrigerant circuit of dehumidification heating mode is changed into the target blowing air temperature (TEO) determined when switching to the cooling circuit refrigerant circuit (TEO). Since it is set lower than TEO), even if the temperature distribution described above occurs in the indoor evaporator (26), the temperature of the hot part of the indoor evaporator (26) exceeds the dew point of the dew condensation water. It is possible to suppress the occurrence of unpleasant odors.

  According to a third aspect of the present invention, in the vehicle air conditioner according to the first or second aspect, the target outlet temperature determining means (S120) determines the target heating temperature for determining the target heating temperature of the indoor condenser (12). The target heating temperature that has a function as a means and is determined when the refrigerant circuit switching means (13 to 24) is switched to the refrigerant circuit in the heating mode is the refrigerant in which the refrigerant circuit switching means (13 to 24) is in the dehumidifying heating mode. It is equivalent to the target heating temperature determined when switching to the circuit.

  According to this, even if the refrigerant circuit in the dehumidifying and heating mode is switched from the refrigerant circuit in the dehumidifying heating mode to the refrigerant circuit in the heating mode in order to reduce the power consumption of the compressor (11), the target heating temperature is the same. Sudden changes in temperature can be suppressed. Accordingly, it is possible to suppress deterioration of the air conditioning feeling of the occupant due to a sudden change in the temperature of the blown air.

  Note that “equivalent” in this claim means that the target heating temperature determined when switching to the refrigerant circuit in the heating mode and the target heating temperature determined when switching to the refrigerant circuit in the dehumidifying heating mode are completely equal. It does not only mean that it has done, but also includes a range that is slightly shifted due to a calculation error or the like of the target blowing temperature determining means (S120).

  In the invention according to claim 4, the compressor (11) that sucks in the refrigerant, compresses and discharges the refrigerant, the outdoor heat exchanger (16) for exchanging heat between the refrigerant and the outdoor air, and the refrigerant and the vehicle are blown into the vehicle interior. Vapor compression refrigeration cycle (26) having an indoor evaporator (26) for evaporating the refrigerant by exchanging heat with the blown air, and an indoor condenser (12) for heating the blown air by exchanging heat between the refrigerant and the blown air 10) and dew condensation water exclusion determining means (S601) for determining that the dew condensation water generated in the indoor evaporator (26) has been removed, and the refrigeration cycle (10) is the indoor evaporator (26). Cooling mode refrigerant circuit that dissipates the amount of heat absorbed by the outdoor heat exchanger to cool the blown air, and heat that is absorbed by the outdoor heat exchanger (16) is dissipated by the indoor condenser (12) and blown air A heating mode refrigerant circuit for heating Refrigerant for switching the refrigerant circuit in the dehumidifying and heating mode in which the amount of heat absorbed by both the indoor evaporator (26) and the outdoor heat exchanger (16) is radiated by the indoor condenser (12) to dehumidify and heat the blown air. Circuit switching means (13-24), and the refrigerant circuit switching means (13-24) is switched to the cooling mode refrigerant circuit or the dehumidifying heating mode refrigerant circuit, and then dew condensation is excluded by the condensed water exclusion determination means (S601). The vehicle air conditioner is switched to the cooling mode refrigerant circuit or the dehumidifying heating mode refrigerant circuit in preference to the heating mode refrigerant circuit until it is determined that water has been removed.

  According to this, the dew condensation water exclusion determining means (S601) is provided, and after the refrigerant circuit switching means (13 to 24) is switched to the cooling mode refrigerant circuit or the dehumidifying heating mode refrigerant circuit, the heating mode refrigerant circuit is changed. Since switching to the cooling mode refrigerant circuit or the dehumidifying and heating mode refrigerant circuit is preferentially performed, it is possible to achieve both suppression of generation of unpleasant odor and reduction of power consumption of the compressor (11).

  That is, once the refrigerant circuit switching means (13 to 24) switches to the cooling mode refrigerant circuit or the dehumidifying and heating mode refrigerant circuit, it is expected that condensed water is generated in the indoor evaporator (26).

  Therefore, after the refrigerant circuit switching means (13 to 24) switches to the cooling mode refrigerant circuit or the dehumidifying heating mode refrigerant circuit, the cooling mode refrigerant circuit or the dehumidifying heating mode refrigerant takes precedence over the heating mode refrigerant circuit. By switching to the circuit, generation of unpleasant odor can be suppressed.

  Furthermore, after it is determined by the condensed water exclusion determining means (S601) that the condensed water generated in the indoor evaporator (26) has been excluded, the cooling mode refrigerant circuit or the dehumidifying heating mode refrigerant circuit is not given priority. Since the refrigerant circuit is switched to the heating mode, the power consumption of the compressor (11) can be reduced.

  In addition, the code | symbol in the parenthesis of each means described in this column and the claim shows an example of a correspondence relationship with the specific means described in the embodiment described later.

It is a whole block diagram which shows the refrigerant circuit at the time of the air conditioning mode of the vehicle air conditioner of 1st Embodiment. It is a whole block diagram which shows the refrigerant circuit at the time of the heating mode of the vehicle air conditioner of 1st Embodiment. It is a whole block diagram which shows the refrigerant circuit at the time of the 1st dehumidification mode of the vehicle air conditioner of 1st Embodiment. It is a whole block diagram which shows the refrigerant circuit at the time of the 2nd dehumidification mode of the vehicle air conditioner of 1st Embodiment. It is a block diagram which shows the electric control part of the vehicle air conditioner of 1st Embodiment. It is a flowchart which shows control of the vehicle air conditioner of 1st Embodiment. It is a flowchart which shows the principal part of control of the vehicle air conditioner of 1st Embodiment. It is a flowchart which shows another principal part of control of the vehicle air conditioner of 1st Embodiment. It is a flowchart which shows another principal part of control of the vehicle air conditioner of 1st Embodiment. It is a flowchart which shows another principal part of control of the vehicle air conditioner of 1st Embodiment. It is a flowchart which shows the principal part of control of the vehicle air conditioner of 2nd Embodiment.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. In this embodiment, the vehicle air conditioner of the present invention is applied to a so-called hybrid vehicle that obtains a driving force for vehicle travel from an internal combustion engine (engine) EG and a travel electric motor. 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. 1-4 respectively show the flow of the refrigerant in the cooling mode, the heating mode, and the first and second dehumidification modes by solid arrows.

  The first dehumidification mode is a dehumidification mode that prioritizes the dehumidification capacity over the heating capacity, and the second dehumidification mode is a dehumidification mode that prioritizes the heating capacity over the dehumidification 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.

  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.

  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.

  1 to 4 is provided with a cooling water pump (not shown) for circulating the 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. Specifically, the cooling water pump may be operated in conjunction with the operation of the engine EG.

  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. Then, the refrigerant circuit switching means of the present embodiment includes an electric three-way valve 13, a low pressure solenoid valve 17, a high pressure solenoid valve 20, and a heat exchange that are in a predetermined valve open state or a valve closed state when power supply is stopped. It comprises a plurality of (five) solenoid valves, ie, a device cutoff solenoid valve 21 and a dehumidification solenoid valve 24.

  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 forefront 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 blown air flow in the casing 31, an inside / outside air switching box (not shown) for switching between the inside air (vehicle compartment air) and the outside air (vehicle compartment outside air) is arranged.

  More specifically, the inside / outside air switching box is formed with an inside air introduction port for introducing inside air into the casing 31 and an outside air introduction port for introducing outside air. Furthermore, an inside / outside air switching door is provided inside the inside / outside air switching box to continuously adjust the opening area of the inside air inlet and the outside air inlet to change the air volume ratio between the inside air volume and the outside air volume. ing.

  Therefore, the inside / outside air switching door 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 is driven by an electric actuator 62 for the inside / outside air switching door, and the operation of the electric actuator 62 is controlled by a control signal output from the air conditioning controller 50.

  Further, as the suction port mode, the inside air mode in which the inside air introduction port is fully opened and the outside air introduction port is fully closed and the inside air is introduced into the casing 31, and the inside air introduction port is fully closed and the outside air introduction port is fully opened. 31. The outside air mode for introducing outside air into the inside 31. Further, by continuously adjusting the opening area of the inside air introduction port and the outside air introduction port between the inside air mode and the outside air mode, the introduction ratio of the inside air and the outside air is continuously adjusted. There is an inside / outside air mixing mode to change to.

  A blower 32 that blows air sucked through the inside / outside air switching box toward the vehicle interior is disposed on the downstream side of the inside / outside air switching box. 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 through which air passes 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 is a heating heat exchanger that heats the air that has passed through the indoor evaporator 26 by exchanging heat between the cooling water of the engine EG that outputs vehicle driving force and the air that has passed through the indoor evaporator 26. is there.

  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, a blower outlet (not shown) for blowing out the blown air whose temperature is adjusted from the mixing space 35 to the vehicle interior that is the space to be cooled is disposed at the most downstream portion of the blown air flow of the casing 31. Specifically, the air outlet includes a face air outlet that blows air-conditioned air toward the upper body of the passenger in the passenger compartment, a foot air outlet that blows air-conditioned air toward the feet of the passenger, and an inner surface of the front window glass of the vehicle. A defroster outlet for blowing air conditioned air is provided.

  Further, on the upstream side of the air flow of the face outlet, the foot outlet, and the defroster outlet, a face door for adjusting the opening area of the face outlet, a foot door for adjusting the opening area of the foot outlet, and the defroster outlet, respectively. A defroster door (none of which is shown) for adjusting the opening area is arranged.

  These face door, foot door, and defroster door constitute an outlet mode switching means for switching the outlet mode, and are connected to an electric actuator 64 for driving the outlet mode door via a link mechanism (not shown). Are operated in conjunction with each other. The operation of the electric actuator 64 is also controlled by a control signal output from the air conditioning controller 50.

  In addition, as the blowout mode, the face blowout port is fully opened and air is blown out from the face blowout port toward the upper body of the passenger in the passenger compartment. Bi-level mode that blows air toward the upper body and feet, foot mode that fully opens the foot outlet and opens the defroster outlet only by a small opening, and mainly blows air from the foot outlet, and the foot outlet and defroster There is a foot defroster mode in which the air outlet is opened to the same extent and air is blown out from both the foot air outlet and the defroster air outlet.

  Furthermore, it can also be set as the defroster mode which fully opens a defroster blower outlet and blows air from a defroster blower outlet to the vehicle front window glass inner surface by operating a switch of the operation panel 60 mentioned later by a passenger | crew manually.

  In addition, the hybrid vehicle to which the vehicle air conditioner 1 of the present embodiment is applied includes an electric heat defogger (not shown) separately from the vehicle air conditioner. The electric heat defogger is a heating wire disposed inside or on the surface of the vehicle interior window glass, and prevents fogging or window fogging by heating the window glass. The operation of the electric heat defogger can be controlled by a control signal output from the air conditioning controller 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

  The air-conditioning control device 50 is configured integrally with the above-described control means for controlling various devices. In the present embodiment, in particular, the operation of the electric motor 11b, which is the discharge capacity changing means of the compressor 11, is activated. The configuration (hardware and software) for controlling (refrigerant discharge capacity) is referred to as discharge capacity control means 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 discharge refrigerant temperature Td of the compressor 11, and a discharge pressure sensor 55 (discharge pressure detection) for detecting the discharge side refrigerant pressure (high pressure side refrigerant pressure) Pd of the compressor 11. Means), an evaporator temperature sensor 56 (evaporator temperature detecting means) for detecting the temperature of air blown from the indoor evaporator 26 (corresponding to the refrigerant evaporation temperature and the evaporator temperature) Te, the first three-way joint 15 and the low pressure solenoid valve 17 A suction temperature sensor 57 for detecting the temperature Tsi of the refrigerant flowing between the engine and the engine, a coolant temperature sensor for detecting the engine coolant temperature Tw, and a relative humidity of the vehicle interior air near the window glass in the vehicle interior. A humidity sensor for the detection signal of the interior window glass near a temperature sensor for detecting the temperature of the air, and sensors such as a window glass surface temperature sensor for detecting the window glass surface temperature of the window glass near is input.

  Note that the discharge-side refrigerant pressure (high-pressure side refrigerant pressure) Pd of the compressor 11 of the present embodiment is from the refrigerant discharge port side of the compressor 11 to the variable throttle mechanism portion 27b inlet side of the temperature expansion valve 27 in the cooling mode. This is the high-pressure side refrigerant pressure of the cycle to reach, and in the other operation modes, the high-pressure side refrigerant pressure of the cycle from the refrigerant discharge port side of the compressor 11 to the fixed throttle 14 inlet side. The discharge pressure sensor 55 is provided to monitor an abnormal increase in the high-pressure side refrigerant pressure even in a general refrigeration cycle.

  The evaporator temperature sensor 56 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.

  Detection values of the humidity sensor, the window glass vicinity temperature sensor, and the window glass surface temperature sensor are used to calculate the relative humidity RHW of the window glass surface. That is, by using the humid air diagram, the relative humidity RHW of the window glass surface can be calculated from the relative humidity of the vehicle interior air near the window glass, the temperature of the vehicle interior air near the window glass, and the window glass surface temperature. .

  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. Specifically, various air conditioning operation switches provided on the operation panel 60 include an operation switch of the vehicle air conditioner 1, an operation mode switching switch, an outlet mode switching switch, an air volume setting switch of the blower 32, an interior temperature of the vehicle There are provided a setting switch, an economy switch for outputting a command for giving priority to power saving of the refrigeration cycle, and the like.

  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 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 vehicle air conditioner operation switch 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 can be charged by supplying power from the commercial power source (external power source) to the battery. 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 is performed until the remaining battery level is equal to or less than the predetermined amount when the vehicle is not connected to the external power source. It is like that.

  In step S2, initialization of flags, timers, control variables, etc. (initialization), 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 internal air temperature detected by the internal air sensor 51, Tam is the external air temperature detected by the external air sensor 52, and Ts is detected by the solar radiation sensor 53. Is the amount of solar radiation. Kset, Kr, Kam, Ks are control gains, and C is a correction constant.

  Moreover, although the heat exchanger target temperature for heating is basically a value calculated by the above-described formula F1, correction for calculating a value lower than TAO calculated by the formula F1 to suppress power consumption is performed. Sometimes it is done.

  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. Details of step S6 will be described with reference to FIG.

  First, in step S61, it is determined whether pre-air conditioning is being performed. When it determines with performing pre air conditioning in step S61, it progresses to step S62 and it is determined whether the external temperature Tam is lower than -3 degreeC. If it is determined in step S62 that the outside air temperature Tam is lower than −3 ° C., it is determined in step S63 that the PTC heater 37 needs to be energized, and the process proceeds to step S7.

  Thus, when the outside temperature Tam is lower than −3 ° C., the reason why it is necessary to energize the PTC heater 37 is that the refrigeration cycle 10 performs heating when the outside temperature Tam is lower than −3 ° C. If this is done, the difference between the high and low pressures of the cycle will increase, the cycle efficiency (COP) will decrease, the refrigerant evaporation temperature in the outdoor heat exchanger 16 will decrease, and the outdoor heat exchanger 16 may be frosted. is there.

  If it is determined in step S62 that the outside air temperature Tam is not lower than −3 ° C., the process proceeds to step S64, and it is determined whether or not the air outlet mode is the face mode. If it is determined in step S64 that the outlet mode is the face mode, the process proceeds to step S65, the COOL cycle is selected, and the process proceeds to step S7. The reason is that the face mode is an operation mode selected mainly in summer, as will be described in step S9 described later.

  If it is determined in step S64 that the outlet mode is not the face mode, the process proceeds to step S66, and it is determined whether or not the economy switch of the operation panel 60 is turned on. If it is determined in step S66 that the economy switch is turned on (ON), the window fogging determination value is set to 110 in step S67 and the process proceeds to step S69. If it is determined in step S66 that the economy switch is not turned on, the window fog determination value is set to 100 in step S68, and the process proceeds to step S69.

  In step S69, it is determined whether or not the relative humidity RHW calculated from the detected values of the humidity sensor, the window glass vicinity temperature sensor, and the window glass surface temperature sensor is larger than the window fogging determination value. If it is determined in step S69 that the relative humidity RHW is not greater than the window fogging determination value, the process proceeds to step S73, the HOT cycle is selected, and the process proceeds to step S7.

  Here, as described in steps S66 to S68, the window fog determination value is set to a smaller value when the economy switch is not turned on than when the economy switch is turned on. Therefore, it is easier to proceed to step S73 when the economy switch is not turned on than when the economy switch is turned on. That is, the HOT cycle is easily selected.

  If it is determined in step S69 that the relative humidity RHW is greater than the window fogging determination value, the process proceeds to step S70. In step S70, the degree of necessity of dehumidification in the vehicle compartment is determined in three stages: “Necessary”, “Necessary small”, and “Necessary”.

  Specifically, as shown in step S70, the degree of necessity for dehumidification is a deviation obtained by subtracting the refrigerant evaporation temperature Te detected by the evaporator temperature sensor 56 from the target blown air temperature TEO described in step S11 described later. It is determined according to the size of TEO-Te.

  When the deviation TEO-Te rises to 2 (° C.) or more as the first reference temperature difference, the degree of dehumidification is changed from “necessary small” to “no need”, and the deviation TEO-Te becomes the second reference temperature When the difference decreases to 1.5 (° C.) or less, the degree of dehumidification is changed from “Necessary” to “Necessary”.

  Similarly, when the deviation TEO-Te rises to 1 (° C.) or more as the third reference temperature, the degree of dehumidification is changed from “necessary” to “necessary small”, and the deviation TEO-Te is the fourth When the temperature falls below 0.5 (° C.) as the reference temperature, the degree of dehumidification is changed from “necessary small” to “necessary”.

  The temperature difference between the first reference temperature difference and the second reference temperature difference and the temperature difference between the third reference temperature and the fourth reference temperature are hysteresis widths for preventing hunting. If it is determined in step S70 that the degree of dehumidification is “Necessary”, the process proceeds to step S73, the HOT cycle is selected, and the process proceeds to step S7.

  If it is determined in step S70 that the degree of dehumidification is “necessary small”, the process proceeds to step S72, the DRY_ALL cycle is selected, and the process proceeds to step S7. If it is determined in step S70 that the degree of dehumidification is “necessary”, the process proceeds to step S71, the DRY_EVA cycle is selected, and the process proceeds to step S7.

  On the other hand, when it determines with pre air conditioning not being performed in step S61, it progresses to step S74 and it is determined whether the external temperature Tam is lower than -3 degreeC. If it is determined in step S74 that the outside air temperature Tam is lower than −3 ° C., the process proceeds to step S75, the COOL cycle is selected, and the process proceeds to step S7.

  When it determines with outside temperature Tam not being lower than -3 degreeC in step S74, it progresses to step S76 and it is determined whether a blower outlet mode is face mode. If it is determined in step S76 that the air outlet mode is the face mode, the process proceeds to step S77, the COOL cycle is selected, and the process proceeds to step S7. The reason is the same as in step S64.

  If it is determined in step S76 that the outlet mode is not the face mode, the process proceeds to step S66 described above.

  In step S <b> 7 shown in FIG. 6, 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 the control map stored in advance in the air conditioning control device 50 based on the TAO determined in step S4.

  More 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 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 based on TAO with reference to a control map stored in advance in the air conditioning controller 50. 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. Further, when it is determined that the window glass is likely to be fogged based on the relative humidity RHW of the window glass surface calculated from the detection value of the humidity sensor or the like, the foot defroster mode or the defroster mode is selected. You may do it.

  In step S10, the target opening degree SW of the air mix door 38 is calculated based on the TAO, the air temperature (refrigerant evaporation temperature) Te 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) disposed in the cold air passage 33 for heating, and is generally 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. Here, a basic method for determining the rotational speed of the compressor 11 will be described. For example, in the cooling mode, the temperature of the blown air blown out from the indoor evaporator 26, that is, the indoor evaporator, is referred to the control map stored in the air conditioning control device 50 in advance based on the TAO determined in step S4. A target blown air temperature TEO of the refrigerant evaporation temperature at 26 is determined.

  Then, a deviation En (TEO-Te) between the target blown air temperature TEO and the refrigerant evaporation temperature Te is calculated, and the deviation En is obtained by subtracting the deviation En-1 calculated last time from the deviation En calculated this time. Based on the fuzzy inference based on the membership function and the rule stored in advance in the air-conditioning control device 50 using the rate Edot (En− (En−1)), the value corresponding to the previous compressor rotational speed fCn−1 A rotational speed change amount ΔfC is obtained.

  In the heating mode, the discharge-side refrigerant pressure (high-pressure side refrigerant pressure) is referred to a control map stored in advance in the air-conditioning control device 50 based on the heating heat exchanger target temperature determined in step S4. A target high pressure PDO of Pd is determined, and a deviation Pn (PDO-Pd) between the target high pressure PDO and the discharge side 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.

  More detailed control contents in step S11 of the present embodiment will be described with reference to FIGS. FIG. 8 is a flowchart for determining the rotational speed change amount ΔfC during the COOL cycle. FIG. 9 shows the determination of the rotational speed change amount ΔfH during the HOT cycle, the DRY_EVA cycle, and the DRY_ALL cycle, and the rotational speed change amount ΔfC. Or it is a flowchart which shows the process after (DELTA) fH determination.

  First, in step S111 of FIG. 8, the first temporary target blown air temperature f (Tamdisp) of the indoor evaporator 26 is referred to based on the outside air temperature Tam with reference to a control map stored in the air conditioning control device 50 in advance. To decide. Specifically, the first temporary target blown air temperature f (Tamdisp) is determined so as to increase as the outside air temperature Tam increases. Further, the first temporary target blown air temperature f (Tamdisp) is determined in the range of 2 ° C. ≦ f (Tamdisp) ≦ 9 ° C.

  In subsequent step S112, based on the TAO determined in step S4, a second temporary target outlet temperature f (TAO) of the indoor evaporator 26 is determined with reference to a control map stored in advance in the air conditioning control device 50. To do. Specifically, the second temporary target blowing temperature f (TAO) is determined so as to increase as TAO increases. Further, the second temporary target blown air temperature f (TAO) is determined in the range of 2 ° C. ≦ f (TAO) ≦ 9 ° C.

  In step S113, the smaller one of the first temporary target blowing air temperature f (Tamdisp) determined in step S111 and the second temporary target blowing air temperature f (TAO) determined in step S112 is set. The target blown air temperature TEO of the blown air blown out from the indoor evaporator 26 is determined.

  Thereby, TEO can be set low at the time of low outside temperature where the possibility of window fogging is high, or at the time of low TAO when the occupant desires blowing of blown air having a low temperature. In addition, since the TEO value is increased with the increase in the outside air temperature and the target outlet temperature TAO, the power consumption of the compressor 11 can be reduced.

  In step S114, the rotational speed change amount ΔfC during the COOL cycle is obtained based on the above-described fuzzy inference, and the process proceeds to step S121 in FIG. Note that a fuzzy rule table used as a rule is described in step S114 of FIG. In this rule table, ΔfC is determined based on the deviation En and the deviation change rate Edot so that frosting of the indoor evaporator 26 is prevented.

  Moreover, in step S115 of FIG. 9, it is determined whether the cooling water pump which circulates the cooling water of the engine EG is operating. If it is determined in step S115 that the cooling water pump is operating, the process proceeds to step S118 with the inlet side blown air temperature flowing into the indoor condenser 12 being the engine cooling water temperature Tw in step S116.

  The reason is that when the cooling water pump is operating, the blown air flowing into the indoor condenser 12 is heated by the heater core 36 arranged on the upstream side of the blower air flow of the indoor condenser 12 to cool the engine. This is because the temperature corresponds to the water temperature Tw.

  If it is determined in step S115 that the cooling water pump is not operating, the flow proceeds to step S118 with the inlet-side blown air temperature flowing into the indoor condenser 12 being the refrigerant evaporation temperature Te of the indoor evaporator 26 in step S117. .

  The reason is that when the cooling water pump is not operating, the blown air cooled by the indoor evaporator 26 is heated by the heater core 36 disposed on the upstream side of the blown air flow of the indoor condenser 12. This is because it flows into the indoor condenser 12 as it is.

  In step S118, the control map stored in advance in the air conditioning control device 50 based on the inlet-side blast air temperature flowing into the indoor condenser 12 set in step S116 or step S117 and the TAO determined in step S4. The provisional target high pressure PDO ′ is calculated with reference to FIG.

  In subsequent step S119, based on the blower motor voltage that is a physical quantity having a correlation with the blown air amount of the blower 32, the PDO correction for correcting the target high pressure PDO 'with reference to the control map stored in the air conditioning control device 50 in advance. Determine the coefficient. In step S120, the provisional target high pressure PDO 'calculated in step S118 is multiplied by the correction coefficient determined in step S119 to determine a target high pressure PDO for the high pressure side refrigerant pressure Pd.

  By determining the target high pressure PDO, the approximate refrigerant discharge capacity of the compressor 11 is determined. Therefore, the suction refrigerant pressure of the compressor 11, that is, the refrigerant evaporation pressure in the heat exchanger acting as an evaporator is also determined. Therefore, determining the target high pressure PDO in step S119 corresponds to determining the target blown air temperature TEO of the blown air blown from the indoor evaporator 26 in the first and second dehumidification modes, for example.

  Furthermore, in the refrigeration cycle 10 in which the accumulator 29 is provided on the suction side of the compressor 11 as in the refrigeration cycle 10 of the vehicle air conditioner 1 of the present embodiment, the compressor 11 intake refrigerant becomes a saturated gas phase refrigerant. Therefore, the discharge refrigerant temperature Td of the compressor 11 is a physical quantity having a correlation with the high-pressure side refrigerant pressure Pd. Therefore, determining the target high pressure PDO in step S119 corresponds to, for example, determining the target heating temperature of the blown air in the indoor condenser 12 in the heating mode and the first and second dehumidification modes.

  According to the study by the present inventors, the target blown air temperature TEO when the operation mode (cycle) determined in step S6 is the first and second dehumidification modes (DRY_EVA cycle or DRY_ALL cycle) is from 2 ° C. It has been found that it is determined to be a low value.

  In step S121, based on the fuzzy inference described above, the rotational speed change amount ΔfH in the HOT cycle, the DRY_EVA cycle, and the DRY_ALL cycle is obtained, and the process proceeds to step S121. Note that a fuzzy rule table used as a rule is described in step S121 in FIG. In this rule table, ΔfH is determined based on the above-described deviation Pn and deviation change rate Pdot so as to prevent an abnormal increase in the high-pressure side refrigerant pressure Pd.

  In subsequent step S122, it is determined whether or not the operation mode (cycle) determined in step S6 is a COOL cycle. If it is determined in step S122 that the operation mode (cycle) determined in step S6 is a COOL cycle, the process proceeds to step S123, and the previous compressor speed fn-1 is determined in step S114 of FIG. The value obtained by adding the rotation speed change amount ΔfC is set as the current compressor rotation speed fn, and the process proceeds to step S12.

  If it is determined in step S122 that the operation mode (cycle) determined in step S6 is not a COOL cycle, the process proceeds to step S124, and the previous compressor speed fn-1 is determined in step S121 of FIG. The value obtained by adding the obtained rotation speed change amount ΔfH is set as the current compressor rotation speed fn, and the process proceeds to step S12.

  The determination of the current compressor speed fn in steps S123 and S124 is not performed every control cycle τ but every predetermined control interval (1 second in this embodiment).

  As is clear from the above description, although not shown in FIGS. 8 and 9, whether or not the operation mode (cycle) determined in step S6 is a COOL cycle when moving from step S10 to step S11. If it is a COOL cycle, the process proceeds to step S111, and if it is not a COOL cycle, the process proceeds to S115.

  Furthermore, the control steps S113 and S120 of the present embodiment constitute target blowing temperature determining means for determining the target blowing air temperature TEO of the blowing air blown out from the indoor evaporator 12.

  Further, the control step S120 also has a function as a target heating temperature determining means for determining the target heating temperature of the indoor condenser 12. Moreover, since the target high pressure PDO determined during the HOT cycle, the DRY_EVA cycle, and the DRY_ALL cycle is equivalent, the target heating temperatures determined during the HOT cycle, the DRY_EVA cycle, and the DRY_ALL cycle are also equivalent.

  In step S <b> 12 shown in FIG. 6, the operation rate (the number of rotations) of the blower fan 16 a that blows outside air toward the outdoor heat exchanger 16 is determined. The basic method for determining the operating rate (number of rotations) of the blower fan 16a of the present embodiment is as follows. That is, the first temporary operating rate (the number of rotations) is determined so that the operating rate (the number of rotations) of the blower fan 16a increases with an increase in the discharge refrigerant temperature Td of the compressor 11, and the engine cooling water temperature Tw The second temporary operation rate (the number of rotations) is determined so that the operation rate (the number of rotations) of the blower fan 16a increases with the increase.

  Further, the larger one of the first and second temporary operating rates (revolutions) is selected, and the selected operating rate (revolutions) is corrected in consideration of noise reduction of the blower fan 16a and vehicle speed. This value is determined as the operating rate (number of rotations) of the blower fan 16a.

  In step S13, the number of operating PTC heaters 37 and the operating state of the electric heat defogger are determined. For example, when the PTC heater 37 is operated in step S6 and the PTC heater 37 needs to be energized, the target opening degree SW of the air mix door 38 is 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 for heating cannot be obtained.

  In addition, 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 is operated.

  Next, in step S14, the operating states of the solenoid valves 13 to 24, which are refrigerant circuit switching means, are determined according to the operation mode determined in step S6 described above. 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 to air-condition the vehicle interior.

  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. When it determines with the vehicle air conditioner 1 not having stopped in step S142, it progresses to step S144.

  Note that the fact that the vehicle air conditioner 1 is stopped in step S142 does not mean that the operation switch of the vehicle air conditioner 1 of the operation panel 60 has been turned off, but the air volume setting switch of the operation panel 60. Means that the air flow rate of the blower 32 is set to 0 and that the vehicle system itself is stopped.

  In step S144, the operating state of each solenoid valve 13-24 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 cooling 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 not 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. Further, when the memory CYCLE_VALVE is set to the second dehumidifying mode (DRY_ALL cycle), the electric three-way valve 13, the low pressure solenoid valve 17, and the dehumidifying 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 any operation mode, it is comprised so that supply of the electric power with respect to at least 1 electromagnetic valve among each electromagnetic valves 13-24 may be stopped. .

  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 air conditioner for a vehicle, sufficient cooling performance can be exhibited by circulating the engine coolant through the heater core 36.

  On the other hand, in the hybrid vehicle as in the present embodiment, if the remaining battery level is sufficient, the vehicle can travel by obtaining the driving force for traveling only from the traveling electric motor. 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, even when high heating performance is required, when the engine coolant temperature Tw is lower than a predetermined reference coolant temperature, the air conditioning control device A request signal is output from 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. In the cooling mode refrigerant circuit, the high-pressure refrigerant radiates heat in the outdoor heat exchanger 16 as described later, so that frost generated in the outdoor heat exchanger 16 can be melted.

  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.

  Next, in 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.

  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.

  Therefore, the 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 by the indoor condenser 12 and further cooled by the outdoor heat exchanger 16. It is cooled by exchanging heat 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.

  Furthermore, in this cooling mode refrigerant circuit, as is apparent from the description of FIG. 1, two different portions in the refrigerant flow path of the refrigeration cycle 10 communicate with each other. In other words, in the cooling mode refrigerant circuit, a closed circuit that does not communicate with other parts is not formed in the refrigerant flow path constituting the refrigeration cycle 10.

(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 portion 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.

  Since the vehicle air conditioner of the present embodiment is configured and operated as described above, the following excellent effects can be exhibited.

  (A) In the refrigeration cycle 10 of the present embodiment, it is possible to switch to a cooling mode refrigerant circuit (COOL cycle) by stopping the supply of electric power to the solenoid valves 13 to 24 that are refrigerant circuit switching means. In the cooling mode, it is possible to avoid the temperature of the electromagnetic valves 13 to 24 themselves from increasing and promoting the deterioration of the coils and the like. That is, deterioration of the durability of the refrigerant circuit switching means can be suppressed. As a result, it is possible to suppress the deterioration of the durability of the cycle component equipment constituting the refrigeration cycle.

  Furthermore, since the cooling mode is mainly used in summer, the temperature in the engine room where the solenoid valves 13 to 24 are arranged is likely to be higher than in other seasons. For this reason, if electric power is continuously supplied to each solenoid valve 13-24 in summer, it will be easy to cause the temperature rise of each solenoid valve 13-24 itself. In this respect, it is very effective to be able to suppress the temperature rise of the electromagnetic valves 13 to 24 themselves in the cooling mode.

  And since the supply of electric power to each solenoid valve 13-24 is stopped at the time of the cooling mode whose use frequency is higher than the refrigerant circuit (HOT cycle) of heating mode, the power consumption as the whole vehicle air conditioner can be reduced. . As a result, power consumption can be reduced throughout the year.

  (B) As described in the control steps S70 to S73, in the vehicle air conditioner 1 of the present embodiment, the refrigerant is switched from the dehumidifying heating mode to the heating mode when the deviation TEO-Te is equal to or greater than the first reference temperature difference. The circuit is switched, and when the deviation TEO-Te becomes equal to or smaller than the second reference temperature difference, the refrigerant circuit is switched from the heating mode to the dehumidifying heating mode. Thereby, reduction of the power consumption of the compressor 11 can be aimed at.

  In other words, when the deviation TEO-Te is equal to or greater than the first reference temperature difference, the refrigerant evaporation temperature Te of the indoor evaporator 26 is sufficiently lowered, so that it is not necessary to further reduce the refrigerant evaporation temperature Te. Therefore, the power consumption of the compressor 11 for reducing the pressure of the refrigerant flowing through the indoor evaporator 26 can be reduced by switching to the heating mode refrigerant circuit that does not exhibit the endothermic effect in the indoor evaporator 26.

  Furthermore, since the refrigerant circuit is switched from the heating mode to the dehumidifying heating mode when the deviation TEO-Te becomes equal to or less than the second reference temperature difference, the air conditioning feeling of the occupant and the generation of unpleasant odors are not caused. .

  That is, when the deviation TEO-Te is equal to or smaller than the second reference temperature difference, the refrigerant evaporation temperature Te of the indoor evaporator 26 may rise and exceed the target blown air temperature TEO. Therefore, by switching to the refrigerant circuit in the dehumidifying and heating mode in which the indoor evaporator 26 exerts an endothermic effect, the refrigerant evaporation temperature Te of the indoor evaporator 26 is lowered again to dehumidify the blown air, and the indoor evaporator 26 It is possible to prevent the dew condensation water that is condensed in step 1 from drying out.

  Therefore, according to the present embodiment, it is possible to achieve both suppression of generation of unpleasant odor and reduction of power consumption of the compressor 11.

  (C) As described in the control steps S66 to S68, in the vehicle air conditioner 1 according to the present embodiment, the heating mode (HOT) is more effective when the economy switch is not turned on than when the economy switch is turned on. Cycle) is easily selected. Therefore, the frequency of switching to the heating mode refrigerant circuit that does not exhibit the endothermic effect in the indoor evaporator 26 is increased, and the power consumption of the compressor 11 for reducing the pressure of the refrigerant flowing through the indoor evaporator 26 is reduced. Easy to make.

  (D) As described in the control steps S111 to S113 and S120, in the vehicle air conditioner 1 of the present embodiment, the target blown air temperature TEO when the COOL cycle is selected is determined to be 2 ° C. or higher. . On the other hand, the target blown air temperature TEO when the HOT cycle, the DRY_EVA cycle, and the DRY_ALL cycle are selected is determined to be a value lower than 2 ° C.

  That is, in the present embodiment, the target blown air temperature TEO determined when the DRY_ALL cycle that is the dehumidifying heating mode is selected is the target blown air that is determined when the COOL cycle that is the cooling mode is selected. It is set lower than the temperature TEO. Thereby, it can suppress that the temperature of the indoor evaporator 26 exceeds the dew point of condensed water as much as possible, and can suppress generation | occurrence | production of an unpleasant odor.

  In other words, in the present embodiment, in the refrigerant circuit in the dehumidifying and heating mode (DRY_ALL cycle) in which the indoor evaporator 26 exerts an endothermic effect, the refrigerant is circulated in the indoor evaporator 26, but the indoor evaporator 26 exhibits the endothermic effect. In the refrigerant circuit in the heating mode (HOT cycle) that is not exhibited, the refrigerant is not circulated in the indoor evaporator 26. Accordingly, the flow rate of the refrigerant flowing through the indoor evaporator 26 varies greatly between the refrigerant circuit in the dehumidifying heating mode and the refrigerant circuit in the heating mode.

  For this reason, in the transition period immediately after switching between the refrigerant circuit in the dehumidifying heating mode and the refrigerant circuit in the heating mode, temperature distribution is likely to occur in the indoor evaporator 26. Therefore, in the portion of the indoor evaporator 26 where the temperature is high, the temperature of the indoor evaporator 26 may exceed the dew point of the condensed water, which may cause an unpleasant odor.

  In contrast, in the present embodiment, the target blown air temperature TEO determined when switching to the refrigerant circuit in the dehumidifying heating mode is changed from the target blown air temperature TEO determined when switching to the refrigerant circuit in the cooling mode. Therefore, even if a temperature distribution occurs in the indoor evaporator 26, the high temperature portion of the indoor evaporator 26 is prevented from exceeding the dew point of the condensed water, and an unpleasant odor is generated. Generation can be suppressed.

  (E) As explained in control step S120, in the vehicle air conditioner 1 of the present embodiment, the target pressure determined when switching to the refrigerant circuit in the heating mode and the refrigerant circuit in the first and second dehumidifying modes. PDO is equivalent. Therefore, the target heating temperature determined when switching to the HOT cycle, the DRY_EVA cycle, and the DRY_ALL cycle is also equivalent.

  Therefore, as described in (B) above, even if the refrigerant circuit in the dehumidifying and heating mode is switched to the refrigerant circuit in the heating mode in order to reduce the power consumption of the compressor 11, the target heating temperature is the same. Therefore, a sudden change in the temperature of the blown air can be suppressed. Accordingly, it is possible to suppress deterioration of the air conditioning feeling of the occupant due to a sudden change in the temperature of the blown air.

  (F) As described in the control step S70, in the vehicle air conditioner 1 of the present embodiment, the degree of necessity of dehumidification in the passenger compartment is set in three stages: “Necessary”, “Necessary Small”, and “Necessary”. When it is determined that the dehumidification is “necessary”, the refrigerant circuit (DRY_EVA cycle) is switched to the first dehumidification mode. Fog can be given priority. That is, priority can be given to safety during vehicle travel.

(Second Embodiment)
In the present embodiment, an example will be described in which the control flow of step S6 is changed as shown in the flowchart of FIG. 11 with respect to the first embodiment. FIG. 11 is a drawing corresponding to FIG. 7 of the first embodiment, and the same or equivalent parts as those of the first embodiment are denoted by the same reference numerals. The same applies to the following drawings.

  Specifically, in step S6 of this embodiment, control steps S601, S602, and S691 are added to FIG. 7 of the first embodiment, and the control contents in the control steps S65, S71, S72, S75, and S77 are changed. In addition to the change, the control steps S66 to S68 are abolished.

  First, in step S601, it is determined whether or not 60 minutes as a reference standby time has elapsed since the vehicle system was stopped. Since the pre-air conditioning is not executed when the vehicle system is stopped, the vehicle air conditioner 1 is also stopped. Further, 60 minutes in step S601 is a value experimentally obtained by the present inventors as a time for the condensed water generated in the indoor evaporator 26 to be naturally dried.

  Therefore, the value of the reference standby time may be longer than 60 minutes. In addition, since the air blower 32 of the vehicle air conditioner 1 is stopped while the vehicle system is stopped, even if the condensed water generated in the indoor evaporator 26 evaporates, an unpleasant odor generated thereby is generated. It never flows into the passenger compartment. That is, step S601 of the present embodiment constitutes dew condensation water exclusion determination means for determining that the dew condensation water generated in the indoor evaporator 26 has been removed.

  If it is determined in step S601 that 60 minutes have elapsed since the stop of the vehicle system, the process proceeds to step S601 and the condensation flag = 0. On the other hand, if it is determined that 60 minutes have not elapsed since the stop of the vehicle system, the process proceeds to step S61. In this case, the value of the previous condensation flag is maintained.

  In step S65, not only the COOL cycle is selected, but also the condensation flag = 1 is set and the process proceeds to step S7. This change to the first embodiment is the same for steps S71, S72, S75, and S77. Furthermore, the window fogging determination value of the present embodiment is set to 100 in the initialization process in step S2.

  In step S691, it is determined whether or not the condensation flag = 1. If the dew condensation flag is 1 in step S691, the process proceeds to step S70. On the other hand, if the dew condensation flag is not 1 in step S691, the process proceeds to step S73, and the HOT cycle is selected.

  That is, in steps S691 and S70 to S73, when the dew condensation flag is 1, the refrigerant circuit (DRY_EVA cycle) in the first dehumidification mode or the second dehumidification mode has priority over the refrigerant circuit (HOT cycle) in the heating mode. The refrigerant circuit (DRY_ALL) is switched.

  The overall configuration and control of the other vehicle air conditioners 1 are the same as in the first embodiment. Therefore, the vehicle air conditioner 1 of the present embodiment can not only obtain the same effects as (A), (B), (D) to (F) of the first embodiment, but also has the following superiority. Can exert the effect.

  (G) As explained in the control steps S691 and S70 to S73, in the vehicle air conditioner 1 of the present embodiment, the electromagnetic valves 13 to 24 are the refrigerant circuit in the cooling mode or the refrigerant in the first and second dehumidifying modes. After switching to the circuit, the dew flag is set to 1, so that the refrigerant circuit in the cooling mode or the refrigerant circuit in the dehumidifying heating mode is switched over in preference to the refrigerant circuit in the heating mode. It is possible to achieve both a reduction in power.

  That is, it is expected that dew condensation water is generated in the indoor evaporator 26 once it is switched to the cooling mode refrigerant circuit or the dehumidifying heating mode refrigerant circuit. Therefore, after switching to the cooling mode refrigerant circuit or the dehumidifying heating mode refrigerant circuit, the indoor evaporator 26 is switched over to the cooling mode refrigerant circuit or the dehumidifying heating mode refrigerant circuit in preference to the heating mode refrigerant circuit. The target blown air temperature TEO can be made lower than that in the heating mode.

  Thereby, since the dew condensation water of the indoor evaporator 26 can be prevented from drying during the operation of the blower 32 of the vehicle air conditioner 1, the generation of unpleasant odor can be suppressed.

  Furthermore, when it is determined in the control step S601 that 60 minutes have passed since the vehicle system was stopped, the condensed refrigerant generated in the indoor evaporator 26 is excluded, and the refrigerant circuit or dehumidifier in the cooling mode is excluded. Since the refrigerant circuit in the heating mode is not prioritized and can be switched to the refrigerant circuit in the heating mode that does not exhibit the endothermic action in the indoor evaporator 26, the power consumption of the compressor 11 can be reduced.

  Therefore, according to the present embodiment, it is possible to achieve both suppression of generation of unpleasant odor and reduction of power consumption of the compressor 11.

(Other embodiments)
The present invention is not limited to the above-described embodiment, and can be variously modified as follows without departing from the spirit of the present invention.

  (1) In step S601 constituting the dew condensation water exclusion determination means of the second embodiment described above, it is determined whether or not a predetermined reference waiting time has elapsed since the stop of the vehicle system. It may be determined whether or not the reference standby time has elapsed after the operation in the refrigerant circuit in the cooling mode or the operation in the first and second dehumidifying modes is stopped.

  Further, it may be determined whether or not the reference standby time has elapsed since the vehicle air conditioner 1 stopped, or whether or not the reference standby time has elapsed since the blower 32 stopped. You may make it determine.

  (2) In the above-described embodiment, an example in which a normal chlorofluorocarbon refrigerant is employed as the refrigerant of the refrigeration cycle 10 has been described, but the type of refrigerant is not limited to this. For example, a hydrocarbon refrigerant or carbon dioxide may be used. Further, the refrigeration cycle 10 may be configured as a supercritical refrigeration cycle in which the high-pressure side refrigerant pressure exceeds the critical pressure of the refrigerant.

  (3) In the above embodiment, for example, in steps S62 and S74 of the first embodiment, it is determined whether or not the outside air temperature Tam is lower than −3 ° C. Of course, the outside air temperature Tam is −3. You may make it determine whether it is below degrees C. or not. The same can be applied to other determination steps within the scope of the present invention.

  (4) The refrigeration cycle 10 applied to the vehicle air conditioner 1 of the present invention described in the above embodiments is applied to a stationary air conditioner, a hot water supply device with an air conditioning function, a cooling / heating device for a vending machine, and the like. May be.

DESCRIPTION OF SYMBOLS 10 Refrigeration cycle 11 Compressor 12 Indoor condenser 13 Electric three-way valve 16 Outdoor heat exchanger 17 Low pressure solenoid valve 20 High pressure solenoid valve 21 Heat exchanger shut-off solenoid valve 24 Dehumidification solenoid valve 26 Indoor evaporator

Claims (4)

Compressor (11) that sucks in refrigerant, compresses and discharges, outdoor heat exchanger (16) that exchanges heat between refrigerant and outdoor air, and refrigerant that exchanges heat between refrigerant and blown air blown into the vehicle interior A vapor compression refrigeration cycle (10) having an indoor evaporator (26) that evaporates, and an indoor condenser (12) that heats the blown air by exchanging heat between the refrigerant and the blown air;
Target blowing temperature determining means (S113, S120) for determining a target blowing air temperature (TEO) of the blown air blown from the indoor evaporator (26);
Evaporator temperature detection means (56) for detecting the refrigerant evaporation temperature (Te) in the indoor evaporator (26),
The refrigeration cycle (10) includes a heating mode refrigerant circuit that heats the blown air by dissipating heat from the outdoor heat exchanger (16) by the indoor condenser (12), and the indoor A refrigerant circuit in a dehumidifying heating mode in which the amount of heat absorbed by both the evaporator (26) and the outdoor heat exchanger (16) is radiated by the indoor condenser (12) to dehumidify and heat the blown air. Refrigerant circuit switching means for switching (13, 17, 20, 21, 24),
In the refrigerant circuit switching means (13 to 24), a deviation (TEO-Te) obtained by subtracting the refrigerant evaporation temperature (Te) from the target blown air temperature (TEO) is equal to or greater than a predetermined first reference temperature difference. Sometimes the refrigerant circuit is switched from the dehumidifying heating mode to the heating mode, and when the deviation (TEO-Te) becomes equal to or smaller than a predetermined second reference temperature difference, the heating mode is switched to the dehumidifying heating mode. A vehicle air conditioner that is switched. Further, the refrigerant circuit switching means (13 to 24) is a cooling mode refrigerant that cools the blown air by dissipating the heat absorbed by the indoor evaporator (26) by the outdoor heat exchanger (16). Has a function to switch to a circuit,
The target blown air temperature (TEO) determined when the refrigerant circuit switching means (13 to 24) is switched to the refrigerant circuit in the dehumidifying and heating mode is determined when switching to the refrigerant circuit in the cooling mode. The vehicle air conditioner according to claim 1, wherein the vehicle air conditioner is set lower than the target blowing air temperature (TEO). The target blowing temperature determining means (S120) has a function as a target heating temperature determining means for determining a target heating temperature of the indoor condenser (12),
The target heating temperature determined when the refrigerant circuit switching means (13 to 24) switches to the refrigerant circuit in the heating mode is the same as the target heating temperature determined by the refrigerant circuit switching means (13 to 24) in the refrigerant circuit in the dehumidifying heating mode. The vehicle air conditioner according to claim 1 or 2, wherein the vehicle air conditioner is equivalent to the target heating temperature determined at the time of switching. Compressor (11) that sucks in refrigerant, compresses and discharges, outdoor heat exchanger (16) that exchanges heat between refrigerant and outdoor air, and refrigerant that exchanges heat between refrigerant and blown air blown into the vehicle interior A vapor compression refrigeration cycle (10) having an indoor evaporator (26) that evaporates, and an indoor condenser (12) that heats the blown air by exchanging heat between the refrigerant and the blown air;
Condensed water exclusion determination means (S601) for determining that the condensed water generated in the indoor evaporator (26) has been excluded,
The refrigeration cycle (10) includes a refrigerant circuit in a cooling mode in which the amount of heat absorbed by the indoor evaporator (26) is radiated by the outdoor heat exchanger to cool the blown air, and the outdoor heat exchanger (16 ) In the heating mode in which the amount of heat absorbed in the indoor condenser (12) is radiated to heat the blown air, and the indoor evaporator (26) and the outdoor heat exchanger (16). Refrigerant circuit switching means (13-24) for switching a refrigerant circuit in a dehumidifying and heating mode in which the amount of heat absorbed by both sides is radiated by the indoor condenser (12) to dehumidify and heat the blown air,
After the refrigerant circuit switching means (13 to 24) is switched to the cooling mode refrigerant circuit or the dehumidifying and heating mode refrigerant circuit, it is determined that the condensed water is excluded by the condensed water exclusion determining means (S601). The vehicle air conditioner is switched to the cooling mode refrigerant circuit or the dehumidifying heating mode refrigerant circuit in preference to the heating mode refrigerant circuit.

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