JP2010236709A - Air conditioner for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent feeding of cold air into a vehicle compartment during defrosting operation of a heat exchanger outside the vehicle compartment, and to improve an air conditioning feeling by preventing from interruption of heating. <P>SOLUTION: This air conditioner 1 for a vehicle includes a heat pump. Whether the heat exchanger 109 outside the vehicle compartment is in a frosted condition or not during heating is estimated. When the heat exchanger 109 is in the frosted condition, a refrigerant discharged from a compressor 100 is supplied to the heat exchanger 109 outside the vehicle compartment by a bypass pipe 110, thereby performing defrosting. Moreover, a refrigerant heater 105 is brought into a heating condition so as to supply a high temperature refrigerant to heat exchangers 10, 11 inside the vehicle compartment, thereby assuring sufficient heating capacity. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vehicle air conditioner using a heat pump.

  Conventionally, a vehicle air conditioner configured to be able to switch between cooling and heating using a heat pump is known (see, for example, Patent Document 1). The heat pump is formed by connecting a compressor for compressing a refrigerant, a vehicle exterior heat exchanger disposed outside the vehicle interior, a pressure reducing valve, and a vehicle interior heat exchanger disposed in the vehicle interior via a pipe. Furthermore, a mode switching valve for switching the refrigerant circulation direction is provided. By switching the refrigerant circulation direction with this mode switching valve, the vehicle interior heat exchanger can be used as a heat sink to generate cold air and the vehicle interior can be cooled, and the vehicle interior heat exchanger can be used as a heat radiator to generate hot air. The interior can be heated.

When the vehicle interior heat exchanger is used as a radiator during heating, the vehicle exterior heat exchanger becomes a heat sink, so moisture in the air condenses on the surface of the vehicle exterior heat exchanger and forms frost, It may not be possible to fully exchange. When defrosting the outside heat exchanger, the mode switching valve temporarily switches the refrigerant circulation direction so that the inside heat exchanger serves as a heat absorber and the outside heat exchanger serves as a heat radiator. . Furthermore, in patent document 1, the blowing mode of the conditioned air during the defrosting operation is a defroster mode in which the conditioned air blows out toward the inner surface of the windshield. Thereby, when performing a defrost operation in the situation where heating is required, cold air does not blow out directly toward the passenger.
Japanese Patent No. 3420269

  However, in Patent Document 1, although it is possible to prevent the cold air from directly hitting the passenger during the defrosting operation, the heating is interrupted and the cold air is supplied into the room even though the room is in a situation where heating is necessary. As a result, the air-conditioning feeling deteriorates.

  The present invention has been made in view of such a point, and an object of the present invention is to prevent cold air from being supplied into the room during the defrosting operation of the vehicle exterior heat exchanger and to prevent heating from being interrupted. It is to improve the air conditioning feeling.

  In order to achieve the above object, in the present invention, the refrigerant discharged from the compressor can be supplied to both the vehicle interior heat exchanger and the vehicle exterior heat exchanger so that the indoor heating is not interrupted without interrupting the interior heating. The defrosting of the vessel is possible, and the refrigerant before being sucked into the compressor can be heated to ensure the heating capacity.

  Specifically, in the first invention, the compressor that compresses the refrigerant, the heat exchanger that is disposed outside the vehicle, the pressure reducing valve that depressurizes the refrigerant, and the vehicle are disposed inside the vehicle. The vehicle interior heat exchanger, the cooling mode in which the refrigerant discharged from the compressor flows in the order of the vehicle exterior heat exchanger, the pressure reducing valve, and the vehicle interior heat exchanger, and the refrigerant discharged from the compressor in the vehicle interior heat. In a vehicle air conditioner having a heat pump in which an exchanger, a pressure reducing valve, and a mode switching valve for switching to a heating mode that flows in order of the vehicle exterior heat exchanger are connected by piping, the discharge side of the compressor and the vehicle exterior heat A bypass pipe that connects the exchanger and supplies the refrigerant discharged from the compressor to the vehicle exterior heat exchanger, an on-off valve that opens and closes the passage of the bypass pipe, and the vehicle interior heat exchange And a refrigerant heater that heats the refrigerant sucked into the compressor and estimates whether the vehicle exterior heat exchanger is in a frosted state or not. And a control device that controls the on-off valve and the refrigerant heater based on the estimation result by the frosting state estimation unit, and the control device uses the frosting state estimation unit to perform the vehicle exterior heat exchanger. Is defrosting operation mode in which the on-off valve is opened and the refrigerant heater is heated, while the vehicle compartment heat exchanger is in a non-frosting state. When it is estimated that, the normal operation mode in which the on-off valve is closed is assumed to be configured.

  According to this configuration, when the frosting state estimating unit estimates that the vehicle exterior heat exchanger is in a frosted state, the high-temperature refrigerant discharged from the compressor by opening the passage of the bypass pipe is converted into the vehicle exterior heat exchanger. To be supplied. Thereby, defrosting of a heat exchanger outside a vehicle interior is attained. When it is estimated that the vehicle exterior heat exchanger is in a frosted state, the refrigerant before being sucked into the compressor is heated by the refrigerant heater. As a result, the temperature of the refrigerant discharged from the compressor can be sufficiently increased, so that the high-temperature refrigerant is supplied to the vehicle interior heat exchanger.

  According to a second aspect, in the first aspect, the compressor is configured as a variable displacement type capable of changing a discharge amount per unit time, and the control device controls the discharge amount of the compressor before switching to the defrosting operation mode. Assume that it is configured to increase.

  That is, when switched to the defrosting operation mode, the refrigerant discharged from the compressor flows into both the vehicle exterior heat exchanger and the vehicle interior heat exchanger, and the amount of refrigerant supplied to the vehicle interior heat exchanger is reduced. There is a concern that the heating capacity will decline temporarily due to a decrease. According to this configuration, since the amount of refrigerant discharged from the compressor increases before switching to the defrosting operation mode, the amount of refrigerant supplied to the vehicle interior heat exchanger is not greatly reduced, and heating is performed. It becomes possible to stop the temporary decline in ability to a minimum.

  According to a third invention, in the second invention, the control device includes an indoor fan that blows air for air conditioning to a vehicle interior heat exchanger, and a blowing state detection unit that detects a blowing state of the indoor fan. It is assumed that the discharge amount of the compressor is increased when the blowing state detection unit detects that the blowing amount of the indoor fan is larger than a predetermined amount, compared to a case where the blowing amount is less than the predetermined amount.

  In other words, a large amount of air blown from the indoor fan requires strong heating, and in this case, it is possible to ensure the required heating capacity by increasing the discharge amount of the compressor. In addition, when the amount of air blown by the indoor fan is small and weak heating is sufficient, the amount of discharge of the compressor is not increased so much, and wasteful consumption of energy is suppressed.

  According to a fourth invention, in the second invention, a temperature detection unit that detects a temperature of air before passing through the vehicle interior heat exchanger is provided, and the control device causes the vehicle interior heat exchanger to be detected by the temperature detection unit. When it is detected that the temperature of the air before passing is lower than the predetermined temperature, the discharge amount of the compressor is increased as compared with the case where the temperature is equal to or higher than the predetermined temperature.

  That is, the low temperature of the air before passing through the vehicle interior heat exchanger is a situation that requires stronger heating. In this case, the required heating capacity is ensured by increasing the discharge amount of the compressor. It becomes possible. Further, when the temperature of the air before passing through the vehicle interior heat exchanger is high and weak heating is sufficient, since the discharge amount of the compressor is not increased so much, wasteful consumption of energy is suppressed.

  According to a fifth aspect, in the second aspect, the apparatus includes a discharge state detection unit that detects a discharge state of the compressor, and the control device uses the discharge state detection unit to discharge the compressor before switching to the defrosting operation mode. When it is detected that the amount is larger than the predetermined amount, it is assumed that the compressor discharge amount is increased as compared with the case where the amount is less than the predetermined amount.

  That is, the fact that the compressor discharge amount is large before switching to the defrosting operation mode is a situation where strong heating is performed.In this case, by increasing the compressor discharge amount, the compressor discharge amount is also increased. Strong heating can be continued. Further, when the discharge amount of the compressor is small before switching to the defrosting operation mode and weak heating is sufficient, since the discharge amount of the compressor is not increased so much, wasteful consumption of energy is suppressed.

  In a sixth aspect, in the first aspect, the control device is configured to put the refrigerant heater in a heated state before switching to the defrosting operation mode.

  According to this configuration, since the refrigerant is heated before switching to the defrosting operation mode, it is possible to prevent the heating capacity from temporarily falling after switching to the defrosting operation mode.

  According to a seventh aspect, in the sixth aspect, the apparatus includes an indoor fan that blows air for air conditioning to the vehicle interior heat exchanger, and a blowing state detection unit that detects a blowing state of the indoor fan. When the blowing state detection unit detects that the blowing amount of the indoor fan is larger than a predetermined amount, the heating amount by the refrigerant heater is increased as compared with a case where the blowing amount is less than the predetermined amount. .

  That is, a large amount of air blown from the indoor fan is a situation where strong heating is required. In this case, by increasing the heating amount of the refrigerant heater, it is possible to ensure the necessary heating capacity. Further, when the amount of air blown by the indoor fan is small and weak heating is sufficient, the amount of heating is not increased so much, and wasteful consumption of energy is suppressed.

  According to an eighth invention, in the sixth invention, a temperature detection unit that detects a temperature of air before passing through the vehicle interior heat exchanger is provided, and the control device causes the vehicle interior heat exchanger to be detected by the temperature detection unit. When it is detected that the temperature of the air before passing is lower than the predetermined temperature, the heating amount by the refrigerant heater is increased as compared with the case where the temperature is higher than the predetermined temperature.

  That is, the low temperature of the air before passing through the vehicle interior heat exchanger is a situation that requires stronger heating.In this case, the heating capacity of the refrigerant heater is increased, so that the required heating capacity is increased. It becomes possible to secure. Further, when the temperature of the air before passing through the vehicle interior heat exchanger is high and weak heating is sufficient, the heating amount of the refrigerant heater is not increased so much, so that wasteful consumption of energy is suppressed.

  According to a ninth aspect, in the sixth aspect, the apparatus further comprises a discharge state detection unit that detects a discharge state of the compressor, and the control device uses the discharge state detection unit to discharge the compressor before switching to the defrosting operation mode. When it is detected that the amount is larger than the predetermined amount, the heating amount of the refrigerant heater is increased as compared with the case where the amount is less than the predetermined amount.

  That is, the fact that the compressor discharge amount is large before switching to the defrosting operation mode is a situation where strong heating is performed. In this case, the defrosting operation is performed by increasing the heating amount of the refrigerant heater. Even at times, it will be possible to continue the strong heating. Further, when the compressor discharge amount is small before switching to the defrosting operation mode and weak heating is sufficient, the heating amount of the refrigerant heater is not increased so much, and wasteful consumption of energy is suppressed.

  In a tenth aspect, in the second aspect, the control device sets the refrigerant heater to a heated state before switching to the defrosting operation mode, and heats the refrigerant heater when the discharge amount of the compressor is increased. Assume that the volume is configured to increase.

  That is, it is possible to suppress a drop in the heating capacity during the defrosting operation by increasing both the discharge amount of the compressor and the heating amount of the refrigerant heater.

  In an eleventh aspect, in any one of the seventh to tenth aspects, the refrigerant heater includes a heating element, and the control device changes at least one of the temperature of the heating element and the heat generation time of the heating element. It shall be comprised as follows.

  According to this configuration, the amount of heat of the refrigerant by the refrigerant heater can be easily changed as intended.

  According to a twelfth aspect, in any one of the first to eleventh aspects, the frosting state estimation unit includes a temperature sensor that detects a surface temperature of the vehicle exterior heat exchanger.

  According to this configuration, since the frost formation state is estimated based on the surface temperature of the vehicle exterior heat exchanger, the estimation result becomes accurate.

  In a thirteenth aspect, in the twelfth aspect, the frost formation state estimation unit estimates that the vehicle exterior heat exchanger is in a frost formation state when the degree of decrease in the surface temperature of the vehicle exterior heat exchanger is greater than or equal to a predetermined value. It shall be comprised as follows.

  That is, when the temperature of the heat exchanger outside the passenger compartment changes to the low temperature side, it is estimated that the degree of change is large, and it is presumed that frost formation is likely to occur. It becomes possible to start.

  In a fourteenth invention, in any one of the first to thirteenth inventions, the frost formation state estimation unit includes a refrigerant pressure sensor that detects a pressure of a refrigerant flowing through the vehicle exterior heat exchanger, and the refrigerant pressure sensor When the detected degree of decrease in the pressure of the refrigerant is equal to or greater than a predetermined value, it is assumed that the vehicle exterior heat exchanger is estimated to be in a frosted state.

  That is, when frost formation starts in the heat exchanger outside the passenger compartment, the heat transfer area decreases and the heat absorption decreases, resulting in a decrease in refrigerant temperature (evaporation pressure), and frost formation proceeds due to the decrease in refrigerant temperature. To go. Therefore, as the frosting progresses, the pressure of the refrigerant flowing through the vehicle exterior heat exchanger decreases, and it is accurately determined whether or not the frosting state is based on the degree of the decrease in the pressure. It becomes possible to estimate.

  In a fifteenth aspect of the invention, in any one of the first to fourteenth aspects, a casing is provided for housing the vehicle interior heat exchanger, and the casing includes an air flow path in which the vehicle interior heat exchanger is disposed; An introduction ratio changing unit for changing an introduction ratio of the air in the passenger compartment and the air flow outside the passenger compartment to the air flow path so that the introduction ratio of the air in the passenger compartment increases in the defrosting operation mode. It is assumed that the introduction ratio changing unit is configured to be controlled.

  According to this configuration, the introduction ratio of air in the passenger compartment increases during the defrosting operation mode. During heating, the temperature of the air in the passenger compartment is higher than the temperature of the air outside the passenger compartment, so that the heating efficiency is improved by increasing the air introduction ratio in the passenger compartment.

  According to a sixteenth aspect, in any one of the first to fourteenth aspects, the casing includes a humidity information acquisition unit that acquires humidity information inside or outside the vehicle compartment, and a casing that houses the vehicle interior heat exchanger. Are provided with an air flow path in which the vehicle interior heat exchanger is disposed, and an introduction ratio changing unit that changes the ratio of introduction of air inside the vehicle interior and air outside the vehicle interior into the air flow path. The configuration that controls the introduction ratio changing unit based on the humidity information acquired by the humidity information acquisition unit and sets the introduction ratio of the air inside the vehicle compartment and the air outside the vehicle compartment so that the humidity inside the vehicle compartment decreases. And

  According to this configuration, condensation is unlikely to occur on the inner surface of the vehicle window.

  According to a seventeenth aspect, in any one of the first to sixteenth aspects, the control device is configured to control the refrigerant heater so that the refrigerant on the suction side of the compressor is in a superheat state. To do.

  According to this configuration, liquid compression of the compressor is prevented and high heating capacity is ensured.

  In an eighteenth aspect, in any one of the first to seventeenth aspects, the control device is configured to put the refrigerant heater in a non-heating state before switching from the defrosting operation mode to the normal operation mode. And

  According to this configuration, since the refrigerant heater is in the heating state during the defrosting operation mode, the preheating is used for a while after switching to the normal operation mode even if the refrigerant heater is not heated before switching to the normal operation mode. Thus, the refrigerant can be heated.

  According to a nineteenth aspect, in any one of the first to eighteenth aspects, an outdoor fan for sending air to the outdoor heat exchanger is provided, and the control device stops the outdoor fan in the defrosting operation mode. It shall be comprised as follows.

  According to this structure, since the ventilation to the vehicle exterior heat exchanger is stopped in the defrosting operation mode, the melting of frost is promoted.

  In a twentieth aspect, in the nineteenth aspect, the control device is configured to operate the outdoor fan after switching from the defrosting operation mode to the normal operation mode.

  That is, when frost is melted in the defrosting operation mode, water is attached to the surface of the outside heat exchanger. At this time, by operating the outdoor fan, water is blown away by the wind. Thereby, re-frosting is suppressed.

  In a twenty-first aspect, in any one of the first to twentieth aspects, the control device is configured to put the refrigerant heater in a non-heated state for a predetermined time before the end of the operation in the defrosting operation mode.

  According to this configuration, since the refrigerant heater is in the heated state during the defrosting operation mode, it is possible to perform heating using the preheating even if the refrigerant heater is in the non-heating state during the defrosting operation mode.

  According to a twenty-second aspect, in any one of the first to twenty-first aspects, a temperature detection unit that detects a temperature state of the conditioned air supplied to the passenger compartment is provided, and the control device detects the conditioned air during the defrosting operation mode. It is assumed that the defrosting operation is interrupted and the normal operation mode is set when the temperature falls below a predetermined temperature.

  According to this configuration, it becomes possible to enter the normal operation mode when the temperature of the air-conditioning wind is lowered to the extent that the occupant feels uncomfortable during the defrosting operation. Yes.

  According to the first aspect of the present invention, when it is estimated that the vehicle exterior heat exchanger is in a frosted state, the high-temperature refrigerant discharged from the compressor can be supplied to the vehicle exterior heat exchanger via the bypass pipe and defrosted. At this time, since the refrigerant before being sucked into the compressor is heated by the refrigerant heater, the heating capacity can be sufficiently increased.

  According to the second aspect of the present invention, the discharge amount of the compressor is increased before switching to the defrosting operation mode, so that a temporary decline in the heating capacity can be suppressed after switching to the defrosting operation mode, which is more comfortable. Heating can be performed.

  According to the third aspect of the invention, since the discharge amount of the compressor is increased when the amount of air blown to the vehicle interior heat exchanger is larger than the predetermined amount, it is high when necessary while suppressing wasteful energy consumption. Heating capacity can be obtained.

  According to the fourth aspect of the invention, when the temperature of the air before passing through the vehicle interior heat exchanger is low, the discharge amount of the compressor is increased, so that it is high when necessary while suppressing wasteful energy consumption. Heating capacity can be obtained.

  According to the fifth aspect, when the discharge amount of the compressor before switching to the defrosting operation mode is large, the discharge amount of the compressor at the time of the defrosting operation is increased, so that strong heating is continuously performed. be able to.

  According to the sixth aspect of the invention, the refrigerant heater is brought into a heating state before switching to the defrosting operation mode, so that a temporary decline in heating capacity can be suppressed after switching to the defrosting operation mode. Comfortable heating can be performed.

  According to the seventh invention, since the heating amount of the refrigerant heater is increased when the amount of air blown to the vehicle interior heat exchanger is larger than a predetermined amount, it is necessary while suppressing wasteful energy consumption. Sometimes a high heating capacity can be obtained.

  According to the eighth invention, since the heating amount of the refrigerant heater is increased when the temperature of the air before passing through the vehicle interior heat exchanger is low, it is necessary while suppressing wasteful energy consumption. Sometimes a high heating capacity can be obtained.

  According to the ninth aspect, since the heating amount of the refrigerant heater is increased when the discharge amount of the compressor before switching to the defrosting operation mode is large, the wasteful energy is obtained while obtaining a high heating capacity when necessary. Can be reduced.

  According to the tenth invention, the refrigerant heater is brought into a heating state before switching to the defrosting operation mode, and the heating amount of the refrigerant heater is increased when the discharge amount of the compressor is increased. Strong heating can be continued during operation.

  According to the eleventh aspect, by changing at least one of the temperature of the heating element and the heating time of the heating element, the heating amount of the refrigerant can be changed easily and as intended, and air conditioning performance can be improved. it can.

  According to the twelfth aspect, since the frost state estimation unit includes the temperature sensor that detects the surface temperature of the heat exchanger outside the passenger compartment, the estimation result of the frost state is accurate, and the frost operation mode is accurate. You can switch to

  According to the thirteenth aspect, when the degree of change of the detected value of the temperature sensor toward the low temperature side is equal to or greater than a predetermined value, the refrigerant heater can be heated and preheating can be started. Thereby, when it switches to defrost operation mode, while being able to defrost quickly, the fall of heating capability can be suppressed.

  According to the fourteenth aspect of the present invention, it is possible to accurately switch the operation mode by estimating whether or not the frosting state is based on the pressure of the refrigerant flowing in the outdoor heat exchanger.

  According to the fifteenth aspect, since the introduction ratio of the air in the passenger compartment is increased during the defrosting operation mode, a sufficient heating capacity can be obtained.

  According to the sixteenth aspect, since the introduction ratio of the air inside the vehicle interior and the air outside the vehicle compartment is changed based on the humidity information, it is possible to suppress the occurrence of condensation on the window of the vehicle.

  According to the seventeenth aspect, since the refrigerant heater is controlled so that the refrigerant on the suction side of the compressor is in a superheat state, high heating capacity can be ensured while preventing damage due to liquid compression of the compressor. .

  According to the eighteenth aspect of the invention, the refrigerant heater can be heated using the preheating of the refrigerant heater by setting the refrigerant heater to an unheated state before switching from the defrosting operation mode to the normal operation mode. It is possible to surely remove the frost from the outside heat exchanger while suppressing the consumption of the vehicle.

  According to the nineteenth aspect, since the outdoor fan is stopped in the defrosting operation mode, frost can be removed quickly, and energy required to remove frost can be reduced.

  According to the twentieth invention, since the outdoor fan is operated after switching from the defrosting operation mode to the normal operation mode, the water generated by the frost melting can be removed from the outdoor heat exchanger. Thereby, re-frosting can be suppressed and the frequency of switching to defrost operation mode can be made low, and energy consumption can be reduced.

  According to the twenty-first aspect, since the refrigerant heater is kept in the non-heated state for a predetermined time before the operation in the defrosting operation mode is completed, heating can be performed using preheating of the refrigerant heater. , Energy consumption can be suppressed.

  According to the twenty-second aspect, since the defrosting operation is interrupted and the normal operation mode is set when the temperature of the air-conditioning air becomes equal to or lower than the predetermined value in the defrosting operation mode, the removal is performed while maintaining passenger comfort. Frost operation can be performed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature, and is not intended to limit the present invention, its application, or its use.

  In the description of the embodiments, for convenience of explanation, “front” means the front side of the vehicle, “rear” means the rear side of the vehicle, and “left” means the left side of the vehicle. Furthermore, “right” represents the right side of the vehicle.

  FIG. 1 shows a schematic structure of a vehicle air conditioner 1 according to an embodiment of the present invention. The vehicle air conditioner 1 is mounted on an electric vehicle or a hybrid vehicle combining an engine and an electric motor.

  The vehicle air conditioner 1 includes an indoor unit U1 mounted in a vehicle interior of the automobile, an outdoor unit U2 mounted outside the vehicle interior of the automobile, and a control device A that controls the indoor unit U1 and the outdoor unit U2. Yes. The indoor unit U1 is disposed at the center in the left-right direction in an instrument panel (not shown) of the automobile. The outdoor unit U2 is mainly disposed in an engine room (not shown).

  The indoor unit U1 includes an inside / outside air switching damper 4, an indoor fan 5, an upstream side interior heat exchanger 10 and a downstream side interior heat exchanger 11, a temperature adjustment damper 27, a rotary damper 35, and a defvent switching damper 55. And a casing 3. On the other hand, the outdoor unit U2 includes a compressor 100 that compresses refrigerant, a pressure reducing valve 101, an electric pressure reducing valve 102, an electromagnetic valve 103, a refrigerant heater 105, a four-way valve (mode switching valve) 106, and an accumulator 107. The vehicle exterior heat exchanger 109 is provided.

  The upstream-side vehicle interior heat exchanger 10 and the downstream-side vehicle interior heat exchanger 11, the compressor 100, the pressure reducing valve 101, the refrigerant heater 105, the four-way valve 106, the accumulator 107, and the vehicle exterior heat exchanger 109. Are connected in a ring shape by pipes 104a to 104h, and the upstream side cabin heat exchanger 10, the downstream side cabin heat exchanger 11 and the outdoor unit U2 constitute a heat pump.

  The compressor 100 has a compression mechanism 100b that is operated by a compressor drive motor 100a, and is a known one that is configured to compress and discharge the sucked refrigerant. As shown in FIG. 3, the compressor drive motor 100 a is controlled by the control device A. The compressor 100 is of a variable displacement type that can change the discharge amount per unit time. Specifically, the rotation speed of the compressor drive motor 100a is configured to be changed by the control device A. In addition, you may make it change the volume of the compression chamber (not shown) which the compression mechanism 100b has.

  The downstream-side vehicle interior heat exchanger 11 is a tube-and-fin type heat exchanger in which tubes through which refrigerant flows and heat transfer fins (both not shown) are alternately stacked. One of the refrigerant supply / exhaust ports (not shown) of the downstream-side vehicle interior heat exchanger 11 is connected to the refrigerant discharge port (not shown) of the compressor 100 via the pipe 104a, and the high temperature discharged from the compressor 100. The refrigerant flows into the downstream-side vehicle interior heat exchanger 11.

  The upstream side vehicle interior heat exchanger 10 is also a tube-and-fin type heat exchanger configured similarly to the downstream side vehicle interior heat exchanger 11. The upstream vehicle interior heat exchanger 10 is larger than the downstream vehicle interior heat exchanger 11. Specifically, the tube length and the width dimension of the upstream vehicle interior heat exchanger 10 are set to be longer than the tube length and the width dimension of the downstream vehicle interior heat exchanger 11, respectively. A pipe 104 c is connected to one (not shown) of the refrigerant supply / exhaust port of the upstream side vehicle interior heat exchanger 10. A pipe 104d is connected to the other (not shown) refrigerant supply / exhaust port of the downstream-side vehicle interior heat exchanger 11. A four-way valve 106 is disposed between the pipe 104b and the pipe 104c.

  A pipe 104d extending from the other refrigerant supply / exhaust port (not shown) of the upstream-side vehicle interior heat exchanger 10 is branched into two, one of which is one of the refrigerant supply / exhaust ports of the refrigerant heater 105 (see FIG. The other extends to one of the refrigerant supply / exhaust ports (not shown) of the vehicle exterior heat exchanger 109.

  A pressure reducing valve 101 is provided on the refrigerant heater 105 side of the pipe 104d. The pressure reducing valve 101 is a well-known one configured to depressurize the refrigerant flowing from the upstream side passenger compartment heat exchanger 10 side of the pipe 104d and to flow to the refrigerant heater 105 side.

  An electric pressure reducing valve 102 is provided on the side of the piping 104d outside the vehicle interior heat exchanger 109. The electric pressure reducing valve 102 is controlled by the control device A, depressurizes the refrigerant flowing from the upstream side interior heat exchanger 10 side of the pipe 104d, and flows it to the outside heat exchanger 109 side; and The refrigerant flowing from the exterior heat exchanger 109 side of the pipe 104d can be depressurized and allowed to flow to the upstream interior heat exchanger 10 side. The electric pressure reducing valve 102 also functions as an on / off valve that opens and closes the pipe 104d.

  The refrigerant heater 105 is a so-called sheathed heater (electric heater) formed by covering a heating wire (heating element) 105a with a metal pipe in an insulated state. The controller A switches the refrigerant heater 105 between ON (heating state) and OFF (non-heating state) and changes the amount of power supplied to the heating wire 105a. The amount of heating can be adjusted by the amount of power supplied.

  The vehicle exterior heat exchanger 109 is a tube-and-fin type heat exchanger, and is disposed, for example, at a front end portion in a vehicle engine room. The outdoor heat exchanger 109 is provided with an outdoor fan 109 a for sending air to the outdoor heat exchanger 109 and an outdoor fan motor 109 b that rotationally drives the outdoor fan 109 a. The outdoor fan motor 109b is controlled by the control device A, and can be switched ON and OFF and the rotation speed can be changed.

  The vehicle exterior heat exchanger 109 is provided with a coolant pressure sensor 109c that detects the pressure of the refrigerant flowing inside, and a surface temperature detection sensor 109d that detects the surface temperature of the vehicle exterior heat exchanger 109. The refrigerant pressure sensor 109c and the surface temperature detection sensor 109d are connected to the control device A.

  A pipe 104 e is connected to the other (not shown) refrigerant supply / exhaust port of the refrigerant heater 105. A pipe 104g is connected to one (not shown) of the refrigerant supply / exhaust port of the accumulator 107. A pipe 104b, a pipe 104c, a pipe 104e, and a pipe 104g are connected to the four ports of the four-way valve 106. The four-way valve 106 is controlled by the control device A, communicates the piping 104b and the piping 104c, and communicates the piping 104e and the piping 104g (shown in FIGS. 1 and 4 to 6), and the piping 104b. It is possible to switch to a state (shown in FIG. 7) in which the pipe 104e is communicated and the pipe 104c and the pipe 104g are communicated.

  In addition, a pipe 104f extending from the other (not shown) refrigerant supply / exhaust port of the vehicle exterior heat exchanger 109 is connected to a midway part of the pipe 104e. A solenoid valve 103 is provided at a connection portion between the pipe 104f and the pipe 104e. The electromagnetic valve 103 is connected to the control device A and can open and close the pipe 104f and the pipe 104e, respectively.

  The accumulator 107 is a known one configured to store a refrigerant. The other refrigerant supply / exhaust port (not shown) of the accumulator 107 is connected to a refrigerant intake port (not shown) of the compressor 100 by a pipe 104h. The pipe 104h is provided with an intake refrigerant pressure sensor 112 and an intake refrigerant temperature sensor 113 that detect the pressure and temperature of the refrigerant before being sucked into the compressor 100, respectively. The suction refrigerant pressure sensor 112 and the suction refrigerant temperature sensor 113 are for detecting whether or not the refrigerant before being sucked into the compressor 100 is in a superheat state (overheated state), and is connected to the control device A. ing.

  The outdoor unit U2 is connected to a refrigerant discharge port of the compressor 100 and the vehicle exterior heat exchanger 109, and a bypass pipe 110 that supplies the refrigerant discharged from the compressor 100 to the vehicle exterior heat exchanger 109, and a bypass pipe 110 A bypass valve (open / close valve) 111 for opening and closing the passage is provided. The upstream end of the bypass pipe 110 is connected to the middle part of the pipe 104a. The bypass valve 111 is positioned at the upstream end of the bypass pipe 110. The downstream end of the bypass pipe 110 is connected to the middle part of the pipe 104d. The bypass valve 111 is controlled by the control device A.

  Further, as shown in FIG. 3, the vehicle includes an outside air temperature sensor 114 that detects an outside temperature (outside air temperature), an outside humidity sensor (humidity information acquisition unit) 115 that detects outside humidity, and a vehicle interior. A vehicle interior humidity sensor (humidity information acquisition unit) 116 for detecting the humidity of the vehicle is provided. The outside air temperature sensor 114, the outside humidity sensor 115, and the inside humidity sensor 116 constitute the vehicle air conditioner 1 and are connected to the control device A.

  The vehicle is also provided with a start timer 118 and a battery remaining amount detection sensor 117. The start timer 118 and the battery remaining amount detection sensor 117 are connected to the control device A.

  The start timer 118 is configured such that the time when the occupant operates the air conditioner 1 can be set. Based on the output signal of the start timer 118, the control device A can obtain how many minutes it is necessary to operate the air conditioner 1.

  The battery remaining amount detection sensor 117 is connected to the battery 120 mounted on the vehicle, and detects the remaining amount of the battery 120. Specifically, the remaining battery level detection sensor 117 is configured to obtain the remaining battery level based on the voltage value of the battery 120.

  Next, the structure of the indoor unit U1 will be described. The casing 3 of the indoor unit U1 is a combination of a resin-made left case component (not shown) and a right case component 2 (shown in FIG. 2). A fan housing 7 that accommodates the indoor fan 5 is formed integrally with other parts on the front side of the upper half of the casing 3. The air from the indoor fan 5 flows downward on the front end side inside the casing 3, and the upstream vehicle interior heat exchanger 10 and the downstream vehicle interior heat exchanger 11 housed in the lower half of the casing 3 After passing, the defroster port 12, the vent port 13 and the foot port 14 formed on the rear side of the casing 3 are supplied to the vehicle compartment.

  The fan housing 7 has a cylindrical shape having a center line extending in the left-right direction, and a sirocco fan constituting the indoor fan 5 is accommodated in a central portion of the fan housing 7 with its rotating shaft directed in the left-right direction. ing. Around the indoor fan 5 of the fan housing 7, an air outflow passage 17 is formed in which the flow of air blown out from the indoor fan 5 gathers, and the downstream end of the air outflow passage 17 opens at the lower side of the fan housing 7. is doing. An attachment port 18 for an indoor fan motor 5a (shown in FIG. 1) for driving the indoor fan 5 is formed on the left side wall of the fan housing 7. The indoor fan motor 5a is attached to the motor attachment port 18 in an airtight manner. The indoor fan 5 is rotatably and integrally attached to the output shaft of the indoor fan motor 5a. The indoor fan motor 5a is connected to the control device A, and the control device A performs ON / OFF switching and rotation speed change. The rotation speed of the indoor fan motor 5a is changed by changing the applied voltage.

  A suction port 19 is formed in the right side wall of the fan housing 7, and an intake box 3 a is connected to the suction port 19. The intake box 3a is formed with an outside air introduction port 3b for introducing air outside the vehicle compartment and an inside air introduction port 3c for introducing air inside the vehicle compartment. Inside / outside air switching damper 4 for adjusting the opening degree of outside air introduction port 3b and inside air introduction port 3c is arranged inside intake box (introduction ratio changing portion) 3a. The inside / outside air switching damper 4 is driven by an inside / outside air switching actuator 4a (shown in FIG. 3) to open the outside air introduction port 3b from a position where the outside air introduction port 3b is fully closed and the inside air introduction port 3c is fully opened. It moves to a position where it is fully open and the inside air inlet 3c is fully closed. When the outside air inlet 3b is fully opened, only outside air is taken into the casing 3, and when the inside air inlet 3c is fully opened, only inside air is taken into the casing 3. Moreover, the introduction ratio of the outside air and the inside air can be arbitrarily changed according to the open / closed degree of the outside air introduction port 3b and the inside air introduction port 3c. The inside / outside air switching actuator 4a is connected to the control device A.

  As shown in FIG. 2, an air guide passage 20 connected to the downstream end of the air outflow passage 17 and extending obliquely rearward is formed on the lower half front end side inside the casing 3. In the air guide passage 20, the upstream side vehicle interior heat exchanger 10 is disposed and accommodated so as to cross the air guide passage 20. The upstream side vehicle interior heat exchanger 10 is oriented so that the direction in which the tube extends is the vertical direction.

  The upstream end of the heating passage 21 communicates with the air guide passage 20. A vertical wall 23 extending upward from the bottom wall of the casing 3 is formed between the upstream end of the heating passage 21 and the air guide passage 20 so as to partition the passages 21 and 20. A lower opening 24 that forms an upstream end opening of the heating passage 21 is formed in the upper half of the vertical wall 23. Further, an upper opening 25 is formed immediately above the lower opening 24 so as to extend from the upper end of the vertical wall 23 to the vicinity of the downstream upper end of the upstream vehicle interior heat exchanger 10. Reference numeral 25 denotes a downstream end opening of the air guide passage 20.

  In the vicinity of the upper end of the vertical wall 23, a plate-like temperature adjusting damper 27 for selectively opening and closing the lower opening 24 and the upper opening 25 is disposed, and the temperature adjusting damper 27 is a support shaft 27a extending in the left-right direction. Is supported by the casing 3. The temperature adjustment damper 27 is driven by a temperature adjustment actuator 27a (shown in FIG. 3). As shown in FIG. 2, the temperature adjustment damper 27 is rotated downward to open the upper opening 25. When fully opened, the lower opening 24 is fully closed. On the other hand, as shown in FIG. 8A, when the temperature adjustment damper 27 is rotated upward to open the lower opening 24, the upper opening 25 is opened. Fully closed. Further, as shown in FIG. 8B, when the temperature adjustment damper 27 is rotated to an intermediate position between the lower opening 24 and the upper opening 25, the lower opening 24 and the upper opening 25 Both of them are in an open state, and the amount of air passing through both the openings 24 and 25 changes depending on the rotation angle of the temperature adjustment damper 27 at this time.

  In the vicinity of the vertical wall 23 of the heating passage 21, the downstream-side vehicle interior heat exchanger 11 is disposed in an inclined state that is located rearward as it goes upward and across the heating passage 21.

  An air mix space 29 in which the downstream end of the air guide passage 20 and the downstream end of the heating passage 21 communicate with each other is formed above the upper opening 25. In the air mix space 29, the temperature is adjusted by mixing the air flowing through the air guide passage 20 and the air flowing through the heating passage 21. That is, depending on the opening degree of the lower opening 24 and the upper opening 25 depending on the rotation angle of the temperature adjustment damper 27, the amount of air flowing through the upstream vehicle interior heat exchanger 10 and the downstream vehicle interior heat exchanger 11 flow. The amount of air changes, whereby the temperature of the air generated in the casing 3 changes.

  In addition, a duct 30 extending substantially in the vertical direction is formed integrally with the other part on the rear side of the casing 3. At the upper end of the duct 30, a defroster port 12 is formed on the front side, and a vent port 13 is formed close to the rear side. The defroster port 12 is connected to a defroster nozzle that opens near the lower end of the front window of the instrument panel via a defroster duct (not shown). Further, the instrument panel has a plurality of vent nozzles for blowing conditioned air toward the occupant's face and chest, and the vent port 13 of the casing 3 is connected to each through a vent duct (not shown). Connected to the vent nozzle. A foot opening 14 is formed at the lower end of the duct 30, and a foot duct (not shown) extending to the feet of the front seat occupant and the feet of the rear seat occupant is connected to the foot opening 14. Yes.

  Formed in the upper half of the duct 30 is a first passage 31 whose upstream end communicates with the upper portion of the air mix space 29 and whose downstream ends are connected to the defroster port 12 and the vent port 13, respectively.

  The lower half of the duct 30 is formed with a second passage 32 whose upstream end communicates with the rear portion of the air mix space 29 and whose downstream end is connected to the foot port 14. The upstream end of the second passage 32 opens forward, and is positioned close to both openings between the downstream end opening of the heating passage 21 and the upstream end opening of the first passage 31. The downstream end opening, the upstream end opening of the second passage 32, and the upstream end opening of the first passage 31 are aligned.

  The second passage 32 extends downwardly from the upstream end opening and then bends and extends substantially vertically downward. The second passage 32 and the downstream side of the heating passage 21 are partitioned by a partition wall 51 formed integrally with the casing 3. The partition wall 51 is curved downward so as to be positioned on the lower side as it goes to the rear side, and the front end portion of the partition wall 51 is formed substantially flat so that a seal material of a rotary damper 35 to be described later contacts. Has been. In addition, a casing-side seal portion 50 with which the sealing material of the rotary damper 35 abuts is inclined forward and downward between the upstream end opening of the first passage 31 and the upstream end opening of the second passage 32 on the inner wall of the casing 3. It is formed in a protruding plate shape. The casing side seal portion 50 is also formed substantially flat like the front end portion of the partition wall 51.

  In the air mix space 29, a rotary damper 35 that switches between the first passage 31 and the second passage 32 by selectively opening and closing the upstream end opening of the first passage 31 and the upstream end opening of the second passage 32 is provided. It is arranged. The rotary damper 35 is connected to a closing wall portion 36 that rotates in the direction in which the upstream end openings of the first passage 31 and the second passage 32 are aligned, and to both ends in the left-right direction that is the rotation axis direction of the closing wall portion 36. And an end wall portion 37. The closing wall portion 36 has a rectangular flat plate shape extending substantially parallel to the rotation axis, and the left and right end wall portions 37 and 37 extend substantially perpendicular to the closing wall portion 36. A support shaft 38 is formed on the left end wall portion 37 so as to protrude leftward, and a similar support shaft 38 is formed on the right end wall portion 37 so as to protrude rightward. The left and right support shafts 38 are coaxially positioned. The left and right support shafts 38 are inserted through through holes (not shown) formed in the left side wall and the right side wall of the casing 3 and supported by the through holes. One support shaft 38 is connected to a blowing direction switching actuator 35a (shown in FIG. 3) via a link mechanism, and the rotary damper 35 is rotated around the support shaft 38 by the actuator 35a. .

  Then, as shown in FIG. 9B, when the rotary damper 35 is rotated to the front side and the upstream end opening of the second passage 32 is fully opened, the upstream end opening of the first passage 31 is slightly opened at the front end side. In this state, the sealing member 40 located on the rear side of the rotary damper 35 comes into contact with the lower surface of the casing side seal portion 50.

  On the other hand, as shown in FIG. 2, when the rotary damper 35 is rotated rearward to fully open the upstream end opening of the first passage 31, the upstream end opening of the second passage 32 is fully closed. In this state, the sealing material 40 positioned on the upper side of the rotary damper 35 abuts on the upper surface of the casing-side seal portion 50, and the sealing material 40 positioned on the lower side of the rotary damper 35 is connected to the partition wall 51. Abuts the front end.

  Further, as shown in FIGS. 8B and 9A, in the state where the rotary damper 35 is rotated halfway between the first passage 31 and the second passage 32, the rotary damper 35 The amount of conditioned air distributed to both passages 31 and 32 varies depending on the rotational position. Further, since the closing wall portion 36 is formed in a flat plate shape and is not in an arc shape along the turning locus, the closing wall portion is located when the rotary damper 35 is in the middle of switching between the first passage 31 and the second passage 32. A gap 52 between the second passage 32 and the first passage 31 side of the air mix space 29 is formed between the casing 36 and the casing-side seal portion 50.

  Also, a defroster side opening 56 and a vent side opening 57 that are opened and closed by the defvent switching damper 55 are formed on the downstream side of the first passage 31 below the defroster port 12 and below the vent port 13, respectively. Yes. The differential vent switching damper 55 is supported on the casing 3 by a support shaft 55a that is formed in a plate shape and extends in the left-right direction, similar to the temperature control damper 27. The differential vent switching damper 55 is interlocked with the rotary damper 35 via a link mechanism, and is driven by a common actuator 35a. As shown in FIG. 9 (a), when the differential vent switching damper 55 is rotated forward to fully close the defroster side opening 56, the vent side opening 57 is fully opened, while as shown in FIG. 9 (b). Further, when the differential vent switching damper 55 is rotated to the rear side and the vent side opening 57 is fully closed, the defroster side opening 56 is fully opened.

  That is, in the vehicle air conditioner 1 of this embodiment, the air passage R is constituted by the air outflow passage 17, the air guide passage 20, the heating passage 21, the air mix space 29, the first passage 31, and the second passage 32. . The air flow path R extends from the suction port 19 of the fan housing 7 constituting the introduction port to the defroster port 12, the vent port 13 and the foot port 14 constituting the outlet port.

  As shown in FIG. 3, the temperature adjusting actuator 27 a and the blowing direction switching actuator 35 a are connected to the control device A and are controlled by the control device A. The control device A is connected to an air conditioning operation switch 41 disposed in the passenger compartment.

  In addition, an inside air temperature sensor (temperature detection unit) 121 that detects the temperature inside the vehicle interior is provided in the vehicle interior. The inside air temperature sensor 121 can detect the temperature of the air-conditioning air before being sucked into the casing 3. The inside air temperature sensor 121 is connected to the control device A.

  The controller A outputs signals from the sensors 109c, 109d, 112 to 117, 121, the operation state of the air conditioning operation switch 41, the operation state of the start timer 118, the remaining amount of the battery 120, the air blowing state in the room, and the operation of the compressor 100. A state is acquired and the indoor unit U1 and the outdoor unit U2 are controlled based on a predetermined program.

  The control device A is provided with a blowing state detection unit 125. The air blowing state detection unit 125 is for detecting the air blowing amount of the air-conditioning air into the casing 3. The rotation speed of the indoor fan motor 5a is changed according to the magnitude of the voltage applied from the control device A, and the air blowing state detection unit 125 is based on the applied voltage to the indoor fan motor 5a. The amount of air blown to can be detected indirectly.

  The control device A is provided with a compressor discharge state detection unit 126. The compressor discharge state detection unit 126 is for detecting the amount of refrigerant discharged from the compressor 100 per unit time. Since the rotation speed of the compressor 100 is changed by a signal output from the control device A, the amount of refrigerant discharged from the compressor 100 is indirectly obtained based on this signal.

  The control device A selects the operation state of the air conditioner 1 from any of the four modes of the low outside air heating operation mode, the normal heating operation mode (the normal operation mode of the present invention), the defrosting operation mode, and the cooling operation mode. Switch to mode. The low outside air heating operation mode is a mode selected when the temperature is low outside air (for example, when the temperature is lower than −5 ° C.) as in the extremely cold season. The normal heating operation mode is a mode selected when the outside air is, for example, −5 ° C. or more and 0 ° C. or less in winter. The defrosting operation mode is a mode that is selected when it is estimated that the vehicle exterior heat exchanger 109 is in a frosted state. The cooling operation mode is a mode selected mainly outside the winter season.

  When the low outside air heating operation mode is selected, the control device A performs the following control so that the upstream side vehicle interior heat exchanger 10 and the downstream side vehicle interior heat exchanger 11 become radiators. As shown in FIG. 4, first, the piping 104b and the piping 104c are communicated by the four-way valve 106, and the piping 104e and the piping 104g are communicated. Further, the electric pressure reducing valve 102 is closed, the passage of the pipe 104e is opened by the electromagnetic valve 103, and the passage of the pipe 104f is closed. Further, the bypass valve 111 is closed and the passage of the bypass pipe 110 is closed. As a result, the refrigerant does not flow through the vehicle exterior heat exchanger 109. In addition, the broken line in the figure has shown the part into which a refrigerant | coolant does not flow.

  The reason why the refrigerant does not flow into the vehicle exterior heat exchanger 109 in the low outside air heating operation mode is that the outside air temperature is low and heat absorption from the atmosphere cannot be expected so much. Then, the refrigerant heater 105 is turned on and the compressor 100 is operated.

  In the low outside air heating operation mode, as indicated by an arrow in the figure, the high-temperature and high-pressure refrigerant discharged from the compressor 100 flows into the downstream side interior heat exchanger 11 from the pipe 104a, and then from the pipe 104b and the pipe 104c. It flows into the upstream side passenger compartment heat exchanger 10. The refrigerant that has flowed through the upstream side vehicle interior heat exchanger 10 is depressurized from the pipe 104d through the pressure reducing valve 101, and then heated by the refrigerant heater 105. The refrigerant heated by the refrigerant heater 105 flows through the pipe 104e, the four-way valve 106, the pipe 104g, the accumulator 107, and the pipe 104h in order, and is sucked into the compressor 100.

  In the case of the low outside air heating operation mode, the temperature of the refrigerant flowing through the downstream-side vehicle interior heat exchanger 11 is higher than the temperature of the refrigerant flowing through the upstream-side vehicle interior heat exchanger 10, so The air heated by passing through the side vehicle interior heat exchanger 10 is reheated when passing through the downstream vehicle interior heat exchanger 11. Thereby, it becomes possible to obtain a high-temperature conditioned air. Further, the temperature of the conditioned air can be adjusted by the rotation operation of the temperature adjustment damper 27.

  When the normal heating operation mode is selected, the control device A performs the following control. As shown in FIG. 5, first, the four-way valve 106 is set in the same manner as in the low outside air heating operation mode. Further, the electric pressure reducing valve 102 is opened. Further, the solenoid valve 103 closes the passage on the refrigerant heater 105 side of the pipe 104e and opens the passage of the pipe 104f. Then, the compressor 100 is operated. In the normal heating operation mode, the refrigerant heater 105 is turned off. This is because atmospheric endotherm can be expected.

  In the normal heating operation mode, as shown in FIG. 5, the high-temperature and high-pressure refrigerant discharged from the compressor 100 flows into the downstream side interior heat exchanger 11 from the pipe 104a, and then passes through the pipe 104b and the pipe 104c. It flows into the indoor heat exchanger 10. The refrigerant flowing through the upstream-side vehicle interior heat exchanger 10 is depressurized through the electric pressure reducing valve 102 from the pipe 104d, and then flows into the vehicle exterior heat exchanger 109. The refrigerant flowing into the exterior heat exchanger 109 exchanges heat with the atmosphere and absorbs heat, and then flows from the pipe 104f through the four-way valve 106 to the pipe 104g, the accumulator 107, and the pipe 104h in order, and is sucked into the compressor 100.

  Also in the normal heating operation mode, high-temperature conditioned air can be obtained as in the low outside air heating operation mode, and the temperature of the conditioned air can be adjusted by the rotation operation of the temperature adjustment damper 27.

  When the defrosting operation mode is selected, the control device A performs the following control. As shown in FIG. 6, first, the four-way valve 106 is set in the same manner as in the low outside air heating operation mode. Further, the electric pressure reducing valve 102 is closed, and the passages of both the pipe 104e and the pipe 104f are opened by the electromagnetic valve 103. Further, the bypass valve 111 is opened to open the passage of the bypass pipe 110. Then, the refrigerant heater 105 is turned on and the compressor 100 is operated.

  In the defrosting operation mode, similarly to the low outside air heating operation mode, the high-temperature and high-pressure refrigerant discharged from the compressor 100 passes through the downstream-side interior heat exchanger 11 and the upstream-side interior heat exchanger 10, and the pressure reducing valve 101. After being decompressed through the refrigerant, it is heated by the refrigerant heater 105. The refrigerant heated by the refrigerant heater 105 is sucked into the compressor 100 through the four-way valve 106 and the accumulator 107. Further, the high-temperature and high-pressure refrigerant discharged from the compressor 100 flows into the vehicle exterior heat exchanger 109 through the bypass pipe 110. Thereby, the surface temperature of the exterior heat exchanger 109 rises and frost is melted.

  In the defrosting operation mode, since the refrigerant before being sucked into the compressor 100 is heated by the refrigerant heater 105, a high-temperature refrigerant can be supplied to the indoor heat exchangers 10 and 11, Heating capacity is fully obtained.

  When the cooling operation mode is selected, the control device A performs the following control. As shown in FIG. 7, first, the four-way valve 106 causes the pipe 104b and the pipe 104e to communicate with each other, and the pipe 104c and the pipe 104g communicate with each other. Further, the electric pressure reducing valve 102 is opened, the passage of the pipe 104e is closed by the electromagnetic valve 103, and the passage of the pipe 104f is opened. Further, the bypass valve 111 is closed and the passage of the bypass pipe 110 is closed.

  In the cooling operation mode, the high-temperature and high-pressure refrigerant discharged from the compressor 100 flows into the downstream-side cabin heat exchanger 11 through the pipe 104a, then flows through the pipe 104b and the pipe 104e, flows through the pipe 104f, and heats outside the vehicle compartment. It flows into the exchanger 109. The refrigerant that has flowed out of the vehicle exterior heat exchanger 109 is decompressed through the electric pressure reducing valve 102, and then flows into the upstream vehicle interior heat exchanger 10 through the pipe 104d. The refrigerant flowing out of the upstream side vehicle interior heat exchanger 10 passes through the pipe 104c, passes through the four-way valve 106, flows in the pipe 104g, the accumulator 107, and the pipe 104h in this order, and is sucked into the compressor 100.

  In the cooling operation mode, the upstream-side vehicle interior heat exchanger 10 functions as a cooler, and the downstream-side vehicle interior heat exchanger 11 functions as a heater. Thereby, the air passing through the air guide passage 20 is cooled by the upstream side vehicle interior heat exchanger 10, and the air passing through the heating passage 21 is heated by the downstream side vehicle interior heat exchanger 11. The temperature adjustment damper 27 can be rotated to adjust the temperature of the conditioned air. In the cooling operation mode, the upstream heat exchanger 10 can reduce the humidity of the air, and then the air can be heated by the downstream heat exchanger 11 to generate hot air.

  Next, the operation of the indoor unit U1 will be described.

  FIG. 9B shows a case where the heat mode is selected in which most of the air in the casing 30 is supplied to the foot duct and the remaining amount is supplied to the defroster nozzle of the instrument panel. In this heat mode, the temperature adjustment damper 27 rotates until the upper opening 25 is fully closed. The air blown by the indoor fan 5 flows through the air guide passage 20 and passes through the upstream side vehicle interior heat exchanger 10. Then, the entire amount of air that has passed through the upstream vehicle interior heat exchanger 10 flows into the heating passage 21, passes through the downstream vehicle interior heat exchanger 11, and flows into the air mix space 29.

  In the heat mode, the rotary damper 35 rotates until it covers most of the upstream end opening of the first passage 31, and the differential vent switching damper 55 rotates until the vent side opening 57 is fully closed. Therefore, most of the high-temperature air generated as described above is blown out from the foot duct to the occupant's feet via the foot opening 14. Further, a small amount of air in the air mix space 29 blows out from the defroster nozzle to the inner surface of the front window through the defroster port 12 and the defroster duct.

  FIG. 2 shows a case where the vent mode for supplying the air in the casing 3 only to the vent nozzle of the instrument panel is selected. In this vent mode, the rotary damper 35 rotates until the second passage 32 is fully closed, and the differential vent switching damper 55 rotates until the defroster side opening 56 is fully closed. Further, the temperature adjustment damper 27 is rotated until the lower opening 24 is fully closed, and the air flowing through the air guide passage 20 directly flows into the air mix space 29 without flowing through the heating passage 21.

  And the conditioned air which flowed into the 1st channel | path 31 from the air mix space 29 blows off to a passenger | crew's face and chest from each vent nozzle via the vent port 13 and a vent duct.

  FIG. 8A shows a case where the defroster mode for supplying conditioned air only to the defroster nozzle of the instrument panel is selected. In the defroster mode, the rotary damper 35 rotates until the second passage 32 is fully closed, as in the vent mode, and the differential vent switching damper 55 rotates until the vent side opening 57 is fully closed. Furthermore, the temperature control damper 27 is rotated until the upper opening 25 is fully closed. The conditioned air flowing into the first passage 31 from the air mix space 29 is blown out from the defroster nozzle to the inner surface of the front window via the defroster port 12 and the defroster duct.

  FIG. 8B shows a case where the differential foot mode for supplying conditioned air to the defroster nozzle and the foot duct of the instrument panel is selected. In this differential foot mode, the rotary damper 35 is rotated to a rotation position in the middle of switching between the first passage 31 and the second passage 32, and the closing wall portion 36 of the rotary damper 35 and the casing side seal portion 50 are A gap 52 is formed between them. Further, the differential vent switching damper 55 is rotated until the vent side opening 57 is fully closed, and the temperature adjustment damper 27 is rotated to an intermediate position between the lower opening 24 and the upper opening 25.

  In this differential foot mode, a part of the air flowing through the air guide passage 20 flows into the heating passage 21 and is heated, and the air in the heating passage 21 and the remaining air in the air guide passage 20 enter the air mix space 29. Inflow and mix. About half of the conditioned air in the air mix space 29 mainly flows into the first passage 31 from the front side of the air mix space 29, and the rest flows into the second passage 32 from below the closed wall portion 36 of the rotary damper 35. To do. At this time, since the upstream end of the second passage 32 is close to the downstream end of the heating passage 21, the temperature of the air flowing into the second passage 32 is higher than the temperature of the air flowing into the first passage 31.

  In this mode, the air flowing from the air mix space 29 into the second passage 32 flows to the first passage 31 side of the air mix space 29 through the gap 52. Since the air in the second passage 32 that has flowed into the air mix space 29 has a relatively high temperature as described above, when mixed with the air on the first passage 31 side of the air mix space 29, the air on the first passage 31 side is mixed. This temperature rises and this air flows into the first passage 31.

  The conditioned air flowing into the first passage 31 is blown out from the defroster nozzle toward the inner surface of the front window via the defroster port 12 and the defroster duct. Further, the air flowing into the second passage 32 is blown out from the foot duct to the passenger's feet via the foot opening 14. At this time, since the temperature of the air flowing into the second passage 32 is higher than the temperature of the air flowing into the first passage 31, the occupant does not feel cold at his feet. Further, since the air in the second passage 32 is mixed with the air in the air mix space 29 and then flows into the first passage 31, the temperature of the air blown from the defroster nozzle and the temperature of the air blown from the foot duct are determined. The difference is within the appropriate range. Furthermore, since the temperature of the air flowing into the first passage 31 increases as described above, it is possible to quickly clear the fog on the inner surface of the front window.

  FIG. 9A shows a case where the bi-level mode for supplying air to the vent nozzle and the foot duct of the instrument panel is selected. In this bi-level mode, the rotary damper 35 is rotated to a rotational position in the middle of switching between the first passage 31 and the second passage 32 as in the differential foot mode, and the closing wall portion 36 of the rotary damper 35 is rotated. A gap 52 is formed between the casing side seal portion 50 and the casing side seal portion 50. The differential vent switching damper 55 is rotated until the defroster side opening 56 is fully closed, and the temperature adjustment damper 27 is rotated to an intermediate position between the lower opening 24 and the upper opening 25.

  In this bi-level mode, about half of the conditioned air in the air mix space 29 flows into the first passage 31 and the rest flows into the second passage 32 as in the differential foot mode. At this time, air having a relatively high temperature flows into the second passage 32.

  In this mode, the air flowing into the second passage 32 from the air mix space 29 flows to the first passage 31 side of the air mix space 29 through the gap 52 and mixes with the air on the first passage 31 side. As a result, the air whose temperature has risen flows into the first passage 31.

  The air flowing into the first passage 31 blows out from the vent nozzle to the occupant's face and chest via the vent port 13 and the vent duct, and the air flowing into the second passage 32 passes through the foot port 14. Blows out from the foot duct to the passenger's feet. At this time, since the temperature of the air flowing into the second passage 32 is relatively high, the occupant does not feel cold at his feet. Moreover, since the air of the 2nd channel | path 32 is made to flow into the air mix space 29, the difference of the temperature of the air which blows off from a vent nozzle and the temperature of the air which blows off from a foot duct is settled in an appropriate range.

  Next, specific control contents performed by the control device A will be described based on the flowcharts of FIGS. 10 and 11.

  In step SA1 after the start of the flowchart of FIG. 10, it is determined whether or not the start timer 118 is ON. If it is determined as YES in Step SA1 and the start timer 118 is ON, the process proceeds to the subsequent Step SA2. If NO is determined in step SA1, the process waits without proceeding to the next step until the start timer 118 is turned on.

  In step SA2, the outside air temperature sensor 114 detects the outside air temperature TG. In step SA3 following step SA2, it is determined whether the outside air temperature is lower than −5 ° C., higher than 0 ° C., or not lower than −5 ° C. and not higher than 0 ° C. When the outside air temperature is lower than −5 ° C. (extreme cold season), the process proceeds to step SA4. When the outside air temperature is −5 ° C. or higher and 0 ° C. or lower, the process proceeds to step SA5. Proceed to

  The temperature used as the standard for determining the outside air temperature in step SA3 is not limited to the above. Whether the heat absorption from the atmosphere cannot be expected so much, whether the heat absorption can be expected, or is the heating unnecessary? What is necessary is just to use the temperature which can determine as a reference.

  In step SA4, it is determined whether or not the time until the air conditioner 1 starts operation (the air conditioner 1 is turned on) is within a predetermined time. The time when the air conditioner 1 starts operation is set by the start timer 118, and the time until the air conditioner 1 starts operation is obtained by comparing the set time of the start timer 118 with the current time. It is supposed to be. For example, the predetermined time of step SA4 is preferably about 10 minutes, but is not limited thereto.

  When it is determined YES in step SA4 and the time until the air conditioner 1 starts operation is within a predetermined time, the process proceeds to step SA7. If it is determined NO in step SA4, the process waits without proceeding to the next step SA7 until the time until the air conditioner 1 starts operation is within a predetermined time.

  In step SA7, the refrigerant heater 105 is turned on to be in a heated state. Thereby, a refrigerant | coolant can be warmed beforehand before the driving | operation of the air conditioning apparatus 1. FIG. Although not shown, it is determined before step SA7 whether the remaining battery level is equal to or greater than a predetermined amount. If the battery remaining amount is equal to or greater than the predetermined amount, the refrigerant heater 105 is turned on in step SA7. If the battery remaining amount is less than the predetermined amount, the refrigerant heater 105 is not turned on and the process proceeds to step SA8.

  Note that the energization time and the amount of supplied power to the refrigerant heater 105 can be changed according to the remaining battery level. If the remaining battery level is low, the energization time to the refrigerant heater 105 is shortened, or the amount of supplied power is reduced. Further, when the battery is being charged as in the case where an external power supply for charging is connected to the vehicle, this is detected, and the energization time to the refrigerant heater 105 is lengthened, or the supplied power The amount may be increased.

  In addition, the start timer 118 may be omitted, and this control may be started by an ON operation by an occupant of the air conditioning operation switch 41. In this case, steps SA4 to SA8 are eliminated.

  In step SA8 following step SA7, it is determined whether or not the air conditioner 1 has started operation. If YES is determined in the step SA8, the process proceeds to a step SA9. If it is determined NO in step SA8, the process waits until the air conditioner 1 starts operation.

  In step SA9, the air conditioner 1 is operated in the above-described low outside air heating operation mode. At this time, since the refrigerant is preheated in step SA7, the start-up of heating can be accelerated. Further, in the low outside air heating operation mode, high-temperature conditioned air can be generated and supplied to the passenger compartment as described above, so that comfort can be improved.

  In step SA10 following step SA9, the discharge amount of the compressor 100 is calculated. This is performed in the compressor discharge state detection unit 126 of the control device A.

  In step SA11 following step SA10, the outside air temperature TG is detected again. In step SA12 following step SA11, it is determined whether or not the air conditioner 1 is turned off. This can be determined based on whether or not the air conditioning operation switch 41 has been turned OFF by the passenger. If it is determined as YES in step SA12 and the air conditioner 1 is turned off, the process proceeds to step SA13 to stop the operation and end.

  When it is determined as NO in step SA12 and the operation of the air conditioner 1 is continued, the process proceeds to step SA14 and the outside air temperature determination similar to that in step SA3 is performed. If the outside air temperature is lower than −5 ° C., the process returns to step SA9 to continue the operation in the low outside air heating operation mode. If the outside air temperature is −5 ° C. or more and 0 ° C. or less, the process proceeds to step SA15. If higher, the process proceeds to Step SA18 described later.

  In step SA15, the discharge amount of the compressor 100 is calculated as in step SA10. In step SA16 following step SA15, since the outside air temperature is −5 ° C. or more and 0 ° C. or less, the air conditioner 1 is operated in the normal heating operation mode described above. And it progresses to the frost formation determination and defrost control flow shown in FIG. This frost determination and defrost control flow will be described later.

  On the other hand, in step SA5, which has been determined that the outside air temperature is determined to be −5 ° C. or more and 0 ° C. or less in step SA3 of the flowchart shown in FIG. 10, it is determined whether or not the air conditioner 1 has started operation as in step SA8. . If YES is determined in the step SA5, the process proceeds to a step SA17. If it is determined NO in step SA5, the process waits until the air conditioner 1 starts operation.

  In step SA17, which is determined to be YES in step SA5, the air conditioner 1 is operated in the normal heating operation mode described above. Then, it progresses to said step SA11, SA12, and when it determines with YES by step SA12, it progresses to step SA13 and the driving | operation of the air conditioner 1 is stopped. On the other hand, if it is determined to be ON in step SA12, the process proceeds to step SA14 to determine the outside air temperature. If the outside air temperature is lower than −5 ° C., the process returns to step SA9 to operate in the low outside air heating operation mode. If it is -5 ° C. or more and 0 ° C. or less, the process proceeds to Steps SA15 and SA16 to continue the operation in the normal heating operation mode, and if it is higher than 0 ° C., the process proceeds to Step SA18 described later.

  Moreover, in step SA6 which progressed by having determined that external temperature is higher than 0 degreeC in step SA3, it is determined whether the air conditioning apparatus 1 started the driving | operation. If YES is determined in the step SA6, the process proceeds to a step SA18. If it is determined NO in step SA6, the process waits until the air conditioner 1 starts operation.

  In step SA18, which is determined as YES in step SA6, the air conditioner 1 is operated in the cooling operation mode described above. Thereafter, the process proceeds to step SA19, and the discharge amount of the compressor 100 is calculated as in step SA10. Then, it progresses to step SA11, SA12, and when it determines with YES by step SA12, it progresses to step SA13 and the driving | operation of the air conditioner 1 is stopped. On the other hand, if it is determined to be ON in step SA12, the process proceeds to step SA14 to determine the outside air temperature. If the outside air temperature is lower than −5 ° C., the process returns to step SA9 to operate in the low outside air heating operation mode. If it is −5 ° C. or more and 0 ° C. or less, the process proceeds to steps SA15 and SA16 to continue the operation in the normal heating operation mode. If it is higher than 0 ° C., the process proceeds to step SA18 and the cooling operation mode is performed. drive.

  Next, frost formation determination and defrost control will be described based on the flowchart shown in FIG. The frosting determination and the defrosting control are performed through step SA16 described above.

  In step SB1 after the start, the output signals of the sensors 109c, 109d, 112 to 117, 121 are captured. In subsequent step SB2, it is estimated whether or not the vehicle exterior heat exchanger 109 is in a frosted state. Step SB2 is a frost formation state estimation unit of the present invention, and this frost formation state estimation unit includes a surface temperature detection sensor 109d of the vehicle exterior heat exchanger 109.

  The estimation procedure in step SB2 will be specifically described. First, the surface temperature of the vehicle exterior heat exchanger 109 is obtained based on the output signal of the surface temperature detection sensor 109d of the vehicle exterior heat exchanger 109. When the surface temperature of the vehicle exterior heat exchanger 109 is at a temperature where frost formation tends to occur near the freezing point, it is estimated that the vehicle exterior heat exchanger 109 is in a frosted state. The temperature at which frost formation easily occurs is, for example, −3 ° C. or lower. In addition, it is preferable to estimate that the exterior heat exchanger 109 is in a frosted state after a predetermined time has elapsed since the surface temperature of the exterior heat exchanger 109 becomes a temperature at which frost formation is likely to occur. Further, when the vehicle exterior heat exchanger 109 estimates the frost formation state, the outside air temperature and the operation state of the air conditioner 1 may be taken into consideration.

  The surface temperature detection sensor 109d may be disposed so as to directly detect the surface temperature of the vehicle exterior heat exchanger 109, or may be disposed in the vicinity of the vehicle exterior heat exchanger 109 to indirectly control the surface temperature. May be detected automatically.

  Further, in step SB2, the degree of change in the surface temperature of the exterior heat exchanger 109 may be detected, and it may be estimated that the frost state is based on the detection result. That is, when the degree of decrease in the surface temperature of the exterior heat exchanger 109 is a predetermined level or more (for example, a decrease rate of 5 ° C. or more per minute), frost is likely to be formed on the surface of the exterior heat exchanger 109. Therefore, if this is detected, it is estimated that the vehicle exterior heat exchanger 109 is in a frosted state.

  In Step SB2, the pressure of the refrigerant flowing through the vehicle exterior heat exchanger 109 is obtained by the refrigerant pressure sensor 109c, and when the pressure is below a predetermined value, the vehicle exterior heat exchanger 109 is in a frosted state. You may make it estimate that there exists. That is, when frosting starts in the vehicle exterior heat exchanger 109, the heat transfer area decreases and the heat absorption amount decreases, resulting in a decrease in refrigerant temperature (evaporation pressure), and frost formation proceeds due to the decrease in refrigerant temperature. I will do it. Therefore, as the frosting progresses, the pressure of the refrigerant flowing through the exterior heat exchanger 109 decreases, and it is accurately estimated whether or not the frosting state is based on this pressure value. Is possible. As a method for setting the predetermined value, a pressure value when frost is not formed in the vehicle exterior heat exchanger 109 is measured, and a value that is, for example, about 20% lower than the pressure value may be set as the predetermined value.

  Further, in step SB2, the degree of change in the pressure of the refrigerant flowing through the outdoor heat exchanger 109 may be detected, and it may be estimated that the frost state is based on the detection result. A large decrease in the pressure of the refrigerant flowing through the vehicle exterior heat exchanger 109 means that frost formation is in progress, and whether or not the frost state is present based on the change rate of the pressure. It becomes possible to estimate accurately.

  In step SB2, whether or not the vehicle exterior heat exchanger 109 is in a frosted state is estimated based on both the surface temperature of the vehicle exterior heat exchanger 109 and the pressure of the refrigerant flowing through the vehicle exterior heat exchanger 109. You may make it do.

  If it is determined as YES in step SB2 and it is estimated that the vehicle exterior heat exchanger 109 is in a frosted state, the process proceeds to step SB3. On the other hand, it is determined NO in step SB2 and the vehicle exterior heat exchanger 109 is When it is estimated that the frosting state is not established, the process returns to step SA11 in the flowchart shown in FIG. 10 and the operation in the normal heating operation mode is continued.

  In step SB3, which is determined to be YES in step SB2, the discharge amount of the compressor 100 is calculated. The discharge amount is basically larger than the amount calculated in step SA15 in the flowchart shown in FIG. The discharge amount is increased as the outside air temperature is lower, the discharge amount is increased as the amount of air blown by the indoor fan 5 is increased, and the discharge amount is increased as the inside air temperature is lower. For example, when the outside air temperature is lower than −10 ° C., the discharge amount is increased as compared with the case of −10 ° C. or higher, and when the air flow rate is larger than the central air volume between the maximum air flow and the minimum air flow, it is less than that. The discharge amount is increased as compared with the case. Further, when the discharge amount of the compressor 100 calculated in step SA15 is larger than the central amount of the maximum discharge amount and the minimum discharge amount, the discharge amount is increased as compared with the case of less than that.

  Thereafter, in step SB4, the heating amount of the refrigerant heater 105 is calculated. The heating amount in step SB4 increases as the outside air temperature decreases, increases as the discharge amount of the compressor 100 calculated in step SB3 increases, and increases as the air blowing amount by the indoor fan 5 increases. Further, the heating amount is increased as the inside air temperature is lower. For example, when the outside air temperature is lower than −10 ° C., the heating amount is increased as compared with the case where it is equal to or higher than −10 ° C., and when the air blowing amount is larger than the central amount between the maximum air amount and the minimum air amount, the amount is less than that. The heating amount is increased compared to the case of. Further, if the discharge amount of the compressor 100 calculated in step SA15 is larger than the central amount of the maximum discharge amount and the minimum discharge amount, the heating amount is increased as compared with the case of less than that.

  In step SB5 following step SB4, the refrigerant heater 105 is turned ON. At this time, the electric power supplied to the refrigerant heater 105 is set to be the heating amount calculated in step SB4. In step SB6 following step SB5, the discharge amount of the compressor 100 is increased so as to be the discharge amount calculated in step SB3.

  In step SB7 following step SB6, superheat control is performed to control the heating amount of the refrigerant heater 105 so that the refrigerant on the suction side of the compressor 100 is in a superheat state. In step SB7, first, the pressure and temperature of the refrigerant on the suction side of the compressor 100 are obtained by the suction refrigerant pressure sensor 112 and the suction refrigerant temperature sensor 113, and whether or not the suction side refrigerant is in the superheat state based on these detection results. Get. Then, the heating amount of the refrigerant heater 105 is corrected so that the refrigerant on the suction side of the compressor 100 is in a superheat state, and the amount of power supplied is controlled to match that. Thereby, the liquid compression of the compressor 100 is prevented.

  In step SB8 following step SB7, the introduction ratio of the air in the vehicle interior and the air outside the vehicle interior is calculated. In step SB8, the introduction ratio of air in the passenger compartment is basically increased. In step SB8, the humidity outside the vehicle compartment and the humidity inside the vehicle compartment are obtained based on the output signals of the humidity sensor 115 outside the vehicle compartment and the humidity sensor 116 inside the vehicle compartment. When the humidity difference is large, the introduction ratio is corrected so that the introduction ratio of air having a lower humidity is increased. In step SB8, the temperature outside the vehicle interior and the temperature inside the vehicle interior are obtained based on the output signals of the outside air temperature sensor 114 and the inside air temperature sensor 121, and correction is performed so as to increase the introduction ratio of the air having the higher temperature. May be.

  In step SB9 following step SB8, the inside / outside air switching damper 4 is moved by controlling the inside / outside air switching actuator 4a so as to achieve the introduction ratio calculated in step SB8.

  In step SB10 following step SB9, the air conditioner 1 is operated in the defrosting operation mode described above. In the defrosting operation mode, the refrigerant discharged from the compressor 100 flows into the vehicle exterior heat exchanger 109 so that the frost is melted. Furthermore, since the refrigerant is heated by the refrigerant heater 105, the temperature and pressure of the refrigerant discharged from the compressor 100 can be sufficiently increased, so that the upstream vehicle interior heat exchanger 10 and the downstream vehicle A high-temperature refrigerant is supplied to the indoor heat exchanger 11 to obtain a sufficient heating capacity.

  In step SB11 following step SB10, the outdoor fan motor 109b is turned OFF. As a result, the cold air outside the vehicle compartment is not actively blown to the heat exchanger 109 outside the vehicle compartment, so that it is possible to quickly defrost the frost.

  In step SB12 following step SB11, it is determined whether it is a predetermined time before the end of the defrosting. That is, the scheduled defrosting end time is set in advance, and it can be determined whether or not it is a predetermined time before the end of the defrosting based on this time and the time when the defrosting operation is started. The scheduled defrosting end time may be a fixed time regardless of the operating state, or may be changed according to the outside air temperature, for example. The predetermined time in this case is preferably about several minutes, for example.

  If it determines with NO by step SB12, it will wait until it becomes the predetermined time before completion | finish of defrosting. On the other hand, in step SB13, which is determined as YES in step SB12, the refrigerant heater 105 is turned off. Even if the refrigerant heater 105 is turned off, the refrigerant can be heated using preheating for a while.

  In step SB14 following step SB13, it is determined whether or not the defrosting is finished. The timing at which the defrosting is completed may be a time when the surface temperature of the exterior heat exchanger 109 rises to 0 ° C. or more and a predetermined time has elapsed, or a time when a certain time has elapsed after starting the defrosting operation. Also good.

  In step SB15, which is determined as YES in step SB14, the outdoor fan motor 109b is turned on. Thereby, since the water adhering to the external heat exchanger 109 is blown off by the wind, re-frosting is suppressed.

  On the other hand, in step SB16, which is determined to be NO in step SB14, it is determined whether or not the temperature of the conditioned air blown from the air conditioner 1 has reached the target temperature. The temperature of the conditioned air can be obtained by providing a temperature sensor (not shown) in the casing 3. The target temperature is set by the temperature setting by the air conditioning operation switch 41 by the occupant, the inside air temperature sensor 121, the outside air temperature sensor 114, and the like.

  If it is determined as YES in step SB16 and the temperature of the conditioned air does not reach the target temperature, the process proceeds to step SB17. In Step SB17, since the air conditioner 1 is operated in the low outside air heating operation mode, the refrigerant heater 105 is turned on. As a result, the temperature of the conditioned air increases and approaches the target temperature, and it becomes difficult for the passenger to feel uncomfortable.

  In step SB18 following step SB17, it is determined whether or not the temperature of the conditioned air has reached the target temperature. If YES is determined in step SB18 and the temperature of the conditioned air reaches the target temperature, the process returns to step SB14. If it determines with NO by step SB18, it will return to step SB17 and the driving | operation by the low outside air heating operation mode will be continued.

  As described above, according to the vehicle air conditioner 1 according to this embodiment, when the vehicle exterior heat exchanger 109 is estimated to be in a frosted state, the passage of the bypass pipe 110 is opened and the compressor 100 The discharged high-temperature refrigerant is supplied to the vehicle exterior heat exchanger 109. Thereby, defrosting of the exterior heat exchanger 109 becomes possible. When it is estimated that the passenger compartment heat exchanger 109 is in a frosted state, the refrigerant before being sucked into the compressor 100 is heated by the refrigerant heater 105. Thereby, since it becomes possible to fully raise the temperature and pressure of the refrigerant | coolant discharged from the compressor 100, a high temperature refrigerant | coolant comes to be supplied to the indoor heat exchangers 10 and 11, and heating capacity is fully raised now. Can do.

  Further, since the amount of refrigerant discharged from the compressor 100 is increased before switching to the defrosting operation mode, the amount of refrigerant supplied to the indoor heat exchangers 10 and 11 when the defrosting operation mode is set. There is no significant decrease, and a temporary decline in the heating capacity can be minimized and more comfortable heating can be performed.

  In addition, when a large amount of air is blown and strong heating is required, the discharge amount of the compressor 100 is increased and the heating amount of the refrigerant heater 105 is increased, so that necessary heating capacity is ensured. Is possible. In addition, when the amount of blown air is small and weak heating is sufficient, the discharge amount of the compressor 100 is not increased so much and the heating amount of the refrigerant heater 105 is reduced, so that wasteful consumption of energy is suppressed.

  In addition, when the temperature of the air before passing through the indoor heat exchangers 10 and 11 is low and strong heating is required, it is possible to ensure the necessary heating capacity by increasing the discharge amount of the compressor 100. Become. Further, when the temperature of the air before passing through the indoor heat exchangers 10 and 11 is high and weak heating is sufficient, the discharge amount of the compressor 100 is not increased so much, and wasteful consumption of energy is suppressed.

  In addition, when the discharge amount of the compressor 100 is large before the switching to the defrosting operation mode and the strong heating is performed, it is possible to continue the strong heating by increasing the discharge amount of the compressor 100. . Moreover, when the discharge amount of the compressor 100 is small before switching to the defrosting operation mode and weak heating is sufficient, since the discharge amount of the compressor 100 is not increased so much, wasteful consumption of energy is suppressed.

  Further, since the refrigerant is heated before switching to the defrosting operation mode, the temperature of the refrigerant discharged from the compressor 100 increases, and the temperature of the refrigerant supplied to the indoor heat exchangers 10 and 11 increases. Thereby, after switching to a defrost operation mode, it can suppress that heating capability comes to fall temporarily.

  In addition, when the amount of air blown is large and strong heating is required, the heating amount of the refrigerant heater 105 can be increased to ensure the necessary heating capacity. In addition, when the amount of blown air is small and weak heating is sufficient, the amount of heating is not increased so much that wasteful consumption of energy is suppressed.

  In addition, when the temperature of the air before passing through the indoor heat exchangers 10 and 11 is low and strong heating is required, the heating amount of the refrigerant heater 105 can be increased to ensure the heating capacity. Become. Further, when the temperature of the air before passing through the indoor heat exchangers 10 and 11 is high and weak heating is sufficient, the heating amount of the refrigerant heater 105 is not increased so much, and wasteful consumption of energy is suppressed. .

  Further, when the discharge amount of the compressor 100 is large before switching to the defrosting operation mode and strong heating is performed, it is possible to continue the strong heating by increasing the heating amount of the refrigerant heater 105. become. Further, when the discharge amount of the compressor 100 is small before switching to the defrosting operation mode and weak heating is sufficient, the heating amount of the refrigerant heater 105 is not increased so much, and wasteful consumption of energy is suppressed.

  Further, since the refrigerant heater 105 is an electric type, the amount of heating can be easily changed as intended.

  Further, since the frost formation state is estimated based on the surface temperature of the exterior heat exchanger 109, the estimation result can be obtained accurately.

  Further, since the refrigerant heater 105 is controlled so that the refrigerant on the suction side of the compressor 100 is in a superheat state, high heating capacity can be secured while preventing the compressor 100 from being damaged by liquid compression.

  In the above embodiment, the indoor fan 5 is accommodated in the same casing 3 as the upstream and downstream heat exchangers 10 and 11, but the upstream and downstream heat exchangers 10 and 11 are included in the casing 3. The indoor fan may be housed in another casing (not shown).

  Moreover, in the said embodiment, although the refrigerant | coolant heater 102 was comprised with the electric heater, it may not be restricted to this but the heater by warm water and the heater by the exhaust gas of a vehicle engine may be sufficient.

  Moreover, the vehicle air conditioner 1 according to the present invention can be mounted on a vehicle other than an electric vehicle or a hybrid vehicle.

  As described above, the vehicle air conditioner according to the present invention is suitable for, for example, an electric vehicle or a hybrid vehicle combining an engine and an electric motor.

It is a figure explaining the schematic structure of the air-conditioner for vehicles concerning an embodiment. It is sectional drawing which shows the internal structure of an indoor unit. It is a block diagram of a vehicle air conditioner. FIG. 2 is a view corresponding to FIG. 1 and showing a refrigerant flow in a low outside air heating operation mode. FIG. 2 is a view corresponding to FIG. 1 and showing a refrigerant flow in a normal heating operation mode. FIG. 2 is a view corresponding to FIG. 1 and showing a refrigerant flow in a defrosting operation mode. FIG. 2 is a view corresponding to FIG. 1 and showing a refrigerant flow in a cooling operation mode. FIG. 2A is a diagram corresponding to FIG. 2 when in the defroster mode, and FIG. 2B is a diagram corresponding to FIG. 2 when in the differential foot mode. FIG. 2A is a diagram corresponding to FIG. 2 when in the bi-level mode, and FIG. 2B is a diagram corresponding to FIG. 2 when in the heat mode. It is a flowchart which shows the control content by a control apparatus. It is a flowchart of frost formation determination and defrost control.

1 Vehicle air conditioner 3 Casing 3a Intake box (introduction ratio changing part)
5 Indoor Fan 10 Upstream Car Interior Heat Exchanger 11 Downstream Car Interior Heat Exchanger 100 Compressor 101 Pressure Reducing Valve 105 Refrigerant Heater 105a Heating Wire (Heating Element)
106 Four-way valve (mode switching valve)
109 Outside heat exchanger 109a Outdoor fan 109c Refrigerant pressure sensor 109d Surface temperature detection sensor 110 Bypass piping 111 Bypass valve (open / close valve)
115 Outside humidity sensor (humidity information acquisition unit)
116 Car interior humidity sensor (humidity information acquisition unit)
121 Inside air temperature sensor (temperature detector)
125 Blowing state detection unit 126 Compressor discharge state detection unit A Control device R Air flow path

Claims (22)

A compressor for compressing the refrigerant;
An outdoor heat exchanger disposed outside the vehicle;
A pressure reducing valve for reducing the pressure of the refrigerant;
A vehicle interior heat exchanger disposed in the vehicle interior;
A cooling mode in which the refrigerant discharged from the compressor flows in the order of the vehicle exterior heat exchanger, the pressure reducing valve, and the vehicle interior heat exchanger, and the refrigerant discharged from the compressor in the vehicle interior heat exchanger, the pressure reducing valve, and the In a vehicle air conditioner having a heat pump in which a mode switching valve that switches to a heating mode that flows in the order of the heat exchanger outside the vehicle is connected by piping,
A bypass pipe for connecting the discharge side of the compressor and the vehicle exterior heat exchanger, and supplying refrigerant discharged from the compressor to the vehicle exterior heat exchanger;
An on-off valve for opening and closing the passage of the bypass pipe;
A refrigerant heater that is provided between the vehicle interior heat exchanger and the suction side of the compressor and that heats the refrigerant sucked into the compressor;
A frosting state estimating unit for estimating whether or not the vehicle exterior heat exchanger is in a frosting state;
A controller for controlling the on-off valve and the refrigerant heater based on the estimation result by the frost formation state estimation unit,
When the frosting state estimating unit estimates that the vehicle exterior heat exchanger is in a frosted state, the control device opens the on-off valve and sets the refrigerant heater to a heated state. The vehicle is configured to be in a normal operation mode in which the on-off valve is closed when the frost operation mode is set and the vehicle exterior heat exchanger is estimated to be in a non-frosting state. Air conditioner. In the vehicle air conditioner according to claim 1,
The compressor is configured as a variable displacement type that can change the discharge rate per unit time.
The control device is configured to increase the discharge amount of the compressor before switching to the defrosting operation mode. In the vehicle air conditioner according to claim 2,
An indoor fan that blows air for air conditioning to the vehicle interior heat exchanger;
A blower state detector for detecting the blower state of the indoor fan,
The control device is configured to increase the discharge amount of the compressor when the air blowing state detection unit detects that the air blowing amount of the indoor fan is larger than a predetermined amount, compared to a case where the air blowing amount is less than the predetermined amount. An air conditioner for a vehicle. In the vehicle air conditioner according to claim 2,
It has a temperature detector that detects the temperature of the air before passing through the vehicle interior heat exchanger,
When the temperature detecting unit detects that the temperature of the air before passing through the vehicle interior heat exchanger is lower than a predetermined temperature, the control device increases the discharge amount of the compressor as compared with a case where the temperature is higher than the predetermined temperature. It is comprised so that it may make it. The vehicle air conditioner characterized by the above-mentioned. In the vehicle air conditioner according to claim 2,
It has a discharge state detector that detects the discharge state of the compressor,
When the control unit detects that the discharge amount of the compressor before switching to the defrosting operation mode is greater than a predetermined amount, the control unit detects the discharge amount of the compressor as compared with a case where the discharge amount is less than the predetermined amount. A vehicle air conditioner configured to increase. In the vehicle air conditioner according to claim 1,
The control device is configured to bring the refrigerant heater into a heated state before switching to the defrosting operation mode. The vehicle air conditioner according to claim 6,
An indoor fan that blows air for air conditioning to the vehicle interior heat exchanger;
A blower state detector for detecting the blower state of the indoor fan,
The control device is configured to increase the amount of heating by the refrigerant heater as compared to a case where the amount of air blown by the indoor fan is greater than a predetermined amount by the air blowing state detection unit, as compared to a case where the amount is less than the predetermined amount. An air conditioner for a vehicle. The vehicle air conditioner according to claim 6,
It has a temperature detector that detects the temperature of the air before passing through the vehicle interior heat exchanger,
When the temperature detecting unit detects that the temperature of the air before passing through the vehicle interior heat exchanger is lower than a predetermined temperature, the controller detects the heating amount by the refrigerant heater as compared with a case where the temperature is equal to or higher than the predetermined temperature. The vehicle air conditioner is characterized by being configured to increase the amount. The vehicle air conditioner according to claim 6,
It has a discharge state detector that detects the discharge state of the compressor,
When the discharge state detection unit detects that the discharge amount of the compressor before switching to the defrosting operation mode is greater than a predetermined amount, the control device heats the refrigerant heater as compared with a case where the discharge amount is less than the predetermined amount. A vehicle air conditioner configured to increase the amount. In the vehicle air conditioner according to claim 2,
The control device is configured to put the refrigerant heater in a heated state before switching to the defrosting operation mode, and to increase the heating amount of the refrigerant heater when the discharge amount of the compressor is increased. A vehicle air conditioner. The vehicle air conditioner according to any one of claims 7 to 10,
The refrigerant heater includes a heating element,
The control device is configured to change at least one of a temperature of the heating element and a heat generation time of the heating element. The vehicle air conditioner according to any one of claims 1 to 11,
The frost formation state estimation unit is provided with a temperature sensor that detects the surface temperature of the heat exchanger outside the passenger compartment. The vehicle air conditioner according to claim 12,
The frost formation state estimation unit is configured to estimate that the vehicle exterior heat exchanger is in a frost formation state when the degree of decrease in the surface temperature of the vehicle exterior heat exchanger is equal to or greater than a predetermined value. Air conditioner. In the vehicle air conditioner according to any one of claims 1 to 13,
The frost formation state estimation unit includes a refrigerant pressure sensor that detects a pressure of the refrigerant flowing through the vehicle exterior heat exchanger, and when the degree of decrease in the refrigerant pressure detected by the refrigerant pressure sensor is equal to or greater than a predetermined value, A vehicle air conditioner configured to estimate that the heat exchanger outside the passenger compartment is in a frosted state. In the vehicle air conditioner according to any one of claims 1 to 14,
It has a casing that houses the vehicle interior heat exchanger,
The casing is provided with an air flow path in which the vehicle interior heat exchanger is disposed, and an introduction ratio changing unit that changes an introduction ratio of the air in the vehicle interior and the air flow path of the air outside the vehicle interior,
The control apparatus is configured to control the introduction ratio changing unit so that the introduction ratio of air in the passenger compartment increases in the defrosting operation mode. In the vehicle air conditioner according to any one of claims 1 to 14,
A humidity information acquisition unit that acquires humidity information inside or outside the vehicle;
A casing that houses the vehicle interior heat exchanger,
The casing is provided with an air flow path in which the vehicle interior heat exchanger is disposed, and an introduction ratio changing unit that changes an introduction ratio of the air in the vehicle interior and the air flow path of the air outside the vehicle interior,
The control device controls the introduction ratio changing unit based on the humidity information acquired by the humidity information acquisition unit, so that the humidity in the vehicle interior is reduced to reduce the introduction ratio of the air inside the vehicle interior and the air outside the vehicle interior. A vehicle air conditioner characterized in that it is set. The vehicle air conditioner according to any one of claims 1 to 16,
The control device is configured to control the refrigerant heater so that the refrigerant on the suction side of the compressor is in a superheat state. The vehicle air conditioner according to any one of claims 1 to 17,
The control device is configured to put the refrigerant heater in a non-heated state before switching from the defrosting operation mode to the normal operation mode. The vehicle air conditioner according to any one of claims 1 to 18,
It has an outdoor fan for sending air to the outdoor heat exchanger,
The control device is configured to stop the outdoor fan during the defrosting operation mode. The vehicle air conditioner according to claim 19,
The control device is configured to operate the outdoor fan after switching from the defrosting operation mode to the normal operation mode. In the vehicle air conditioner according to any one of claims 1 to 20,
The control device sets the refrigerant heater to a non-heated state for a predetermined time before the end of the operation in the defrosting operation mode. In the vehicle air conditioner according to any one of claims 1 to 21,
It has a temperature detector that detects the temperature of the conditioned air supplied to the passenger compartment,
The control device is configured to interrupt the defrosting operation and set to a normal operation mode when the temperature of the conditioned air becomes equal to or lower than a predetermined temperature during the defrosting operation mode. .

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