JP2014019177A - Vehicular air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable defrosting to be surely performed in a short period of time even if a degree of frosting is high both on the coolant inlet side and outlet side of a heat exchanger outside a vehicle compartment in a heating operation mode.SOLUTION: When a frosting determination part determines that a degree of frosting at a coolant inlet side is higher than at the outlet side in a heating operation mode in a heat exchanger 33 outside a vehicle compartment, a high-pressure coolant is supplied to a spot that has been used as a coolant inlet in the heating operation mode of the heat exchanger 33 outside the vehicle compartment. When the frosting determination part determines that a degree of frosting at a coolant outlet side in a heating operation mode of the heat exchanger 33 outside the vehicle compartment is higher than at the inlet side, a high-pressure coolant is supplied to a spot that has been used as a coolant outlet in the heating operation mode of the heat exchanger 33 outside the vehicle compartment.

Description

  The present invention relates to a vehicle air conditioner mounted on a vehicle.

  Conventionally, for example, an air conditioner including a heat pump device is known as an air conditioner mounted in a hybrid vehicle, an electric vehicle, or the like (see, for example, Patent Documents 1 and 2).

  These vehicle heat pump devices connect an electric compressor, a vehicle exterior heat exchanger disposed outside the vehicle interior, an expansion valve, and a vehicle interior heat exchanger disposed in the vehicle interior in order by refrigerant piping. Configured. In the cooling operation mode, the vehicle interior heat exchanger acts as a heat absorber, and the vehicle exterior heat exchanger acts as a radiator. On the other hand, in the heating operation mode, the vehicle interior heat exchanger acts as a radiator and the vehicle exterior heat exchanger acts as a heat absorber.

  In the heating operation mode, frost formation occurs in the outside heat exchanger acting as a heat absorber. When the heat exchanger outside the passenger compartment is frosted, the performance as a heat absorber is lowered, so it is necessary to defrost. In Patent Documents 1 and 2, when the vehicle exterior heat exchanger is frosted in the heating operation mode, the high temperature refrigerant is supplied to the vehicle exterior heat exchanger so as to be switched to the defrost operation for increasing the surface temperature. It has become.

JP 2011-5983 A JP 2011-255735 A

  The vehicle exterior heat exchanger is provided with a refrigerant inlet and outlet. Depending on the operating condition of the air conditioner, the structure of the heat exchanger outside the passenger compartment, the position of the heat exchanger outside the passenger compartment relative to the vehicle body (how the running wind flows), etc. Thus, it is conceivable that there is a situation where frost formation is likely to occur and, on the contrary, a situation where the refrigerant inlet side is more likely to frost than the refrigerant outlet side.

  However, in the above Patent Documents 1 and 2, since the refrigerant is supplied to the same inlet of the vehicle exterior heat exchanger even in the heating operation or the defrosting operation, the refrigerant is caused to flow out from the same outlet. For example, when frosting starts from the refrigerant outlet side of the vehicle exterior heat exchanger, the high-pressure refrigerant passes through the refrigerant inlet side of the vehicle exterior heat exchanger to the refrigerant outlet side even when switching from heating operation to defrosting operation. Therefore, the temperature drops until the refrigerant reaches the frosted refrigerant outlet side. As a result, the increase in the surface temperature of the frosted portion is delayed, the defrosting time is prolonged, and the passenger comfort is deteriorated.

  The present invention has been made in view of such points, and the object of the present invention is that the degree of frost formation on the refrigerant inlet side and the refrigerant outlet side of the vehicle exterior heat exchanger is high in the heating operation mode. However, it is to enable defrosting reliably in a short time.

  In order to achieve the above object, in the present invention, the high-pressure refrigerant can be supplied from either the refrigerant inlet side or the refrigerant outlet side in the heating operation mode of the vehicle exterior heat exchanger.

1st invention includes the compressor which compresses a refrigerant | coolant, the vehicle interior heat exchanger arrange | positioned in a vehicle interior, the vehicle exterior heat exchanger arrange | positioned outside a vehicle interior, and an expansion valve, The said compression A heat pump device formed by connecting a machine, the vehicle interior heat exchanger, the expansion valve, and the vehicle exterior heat exchanger by a refrigerant pipe;
A vehicle interior air conditioning unit configured to house the vehicle interior heat exchanger and to have a blower that blows air for air conditioning in the vehicle interior heat exchanger and to generate conditioned air and supply the conditioned air to the vehicle interior; ,
An air conditioner for a vehicle comprising an air conditioning control device for controlling the heat pump device,
The air conditioning control device includes an operation mode of the heat pump device, a heating operation mode in which the vehicle interior heat exchanger is a radiator, and the vehicle exterior heat exchanger is a heat absorber, and a high pressure refrigerant in the vehicle exterior heat exchanger. And switching between a plurality of operation modes including a defrosting operation mode in which defrosting is performed and defrosting between the refrigerant inlet side and the refrigerant outlet side in the heating operation mode in the vehicle exterior heat exchanger. It has a frosting determination unit that individually obtains the degree of frost,
When the frosting determination unit determines that the refrigerant inlet side in the heating operation mode of the vehicle exterior heat exchanger has a higher degree of frost formation than the refrigerant outlet side, the air conditioning control device in the vehicle exterior heat exchanger While supplying high-pressure refrigerant to the location that was the refrigerant inlet in the heating operation mode, when the frosting determination unit has a higher degree of frost formation on the refrigerant outlet side in the heating operation mode in the vehicle exterior heat exchanger than the refrigerant inlet side When judged, the high-pressure refrigerant is supplied to the location that was the refrigerant outlet in the heating operation mode in the vehicle exterior heat exchanger.

According to this configuration, when the degree of frost formation on the refrigerant inlet side of the vehicle exterior heat exchanger is high during the heating operation mode, the frosting degree is switched to the defrost operation mode, and the refrigerant inlet at the heating operation mode in the vehicle exterior heat exchanger is On the other hand, if the degree of frost formation on the refrigerant outlet side of the vehicle exterior heat exchanger is high during the heating operation mode, it is switched to the defrost operation mode and heating in the vehicle exterior heat exchanger is performed. The high-pressure refrigerant is supplied to the location that was the refrigerant outlet in the operation mode.

  Thereby, it becomes possible to defrost by raising the surface temperature of the side where the degree of frost formation of the vehicle exterior heat exchanger is high.

According to a second invention, in the first invention,
The frosting determination unit constitutes refrigerant superheat degree calculation means for calculating the refrigerant superheat degree on the refrigerant outlet side in the vehicle exterior heat exchanger of the heat pump device, and the refrigerant calculated by the refrigerant superheat degree calculation means If the degree of superheat is 0 degree or more, it is determined that the refrigerant inlet side in the heating operation mode in the vehicle exterior heat exchanger has a higher degree of frost formation than the refrigerant outlet side, while if the refrigerant superheat degree is less than 0 degree. The refrigerant outlet side in the heating operation mode in the vehicle exterior heat exchanger is configured to determine that the degree of frost formation is higher than that of the refrigerant inlet side.

  According to this configuration, the fact that the degree of refrigerant superheating on the refrigerant outlet side of the vehicle exterior heat exchanger is 0 ° or more determines that the refrigerant is completely evaporated in the region of the refrigerant outlet side of the vehicle exterior heat exchanger. Is done. In this case, it is estimated that frost formation starts from the refrigerant inlet side of the vehicle exterior heat exchanger. Therefore, in this case, the determination of the degree of frost formation is accurately performed by determining that the degree of frost formation on the refrigerant inlet side in the heating operation mode in the vehicle exterior heat exchanger is high.

  Further, the fact that the refrigerant superheat degree on the refrigerant outlet side of the vehicle exterior heat exchanger is less than 0 degrees means that the refrigerant is not in the superheated gas state on the exit side of the vehicle exterior heat exchanger. In this case, it is estimated that frosting starts from the refrigerant outlet side of the vehicle exterior heat exchanger due to a decrease in saturation temperature caused by refrigerant pressure loss. Therefore, in this case, the determination of the degree of frost formation is accurately performed by determining that the degree of frost formation on the refrigerant outlet side in the heating operation mode in the vehicle exterior heat exchanger is high.

According to a third invention, in the first invention,
An inlet side air temperature sensor for detecting an air temperature after passing through the refrigerant inlet side in the heating operation mode in the vehicle exterior heat exchanger;
An outlet side air temperature sensor for detecting an air temperature after passing through the refrigerant outlet side in the heating operation mode in the vehicle exterior heat exchanger,
When the air temperature detected by the inlet-side air temperature sensor is lower than the air temperature detected by the outlet-side air temperature sensor, the frosting determination unit is in the heating operation mode in the vehicle exterior heat exchanger. If the refrigerant outlet side determines that the degree of frost formation is higher than the refrigerant inlet side, and the air temperature detected by the inlet side air temperature sensor is higher than the air temperature detected by the outlet side air temperature sensor, the vehicle The refrigerant inlet side in the heating operation mode in the outdoor heat exchanger is configured to determine that the degree of frost formation is higher than that of the refrigerant outlet side.

  According to this configuration, when the degree of frost formation on the refrigerant inlet side in the heating operation mode in the exterior heat exchanger is high, the efficiency of heat exchange on the refrigerant inlet side is reduced, and the air temperature is lower than that on the outlet side. Get higher. On the other hand, when the degree of frost formation on the refrigerant outlet side in the heating operation mode in the vehicle exterior heat exchanger is high, the efficiency of heat exchange on the refrigerant outlet side is reduced and the air temperature is higher than that on the inlet side. By using this to determine the degree of frost formation, it is possible to accurately determine which side of the vehicle exterior heat exchanger has the higher degree of frost formation.

According to a fourth invention, in any one of the first to third inventions,
The heat pump device includes first and second vehicle interior heat exchangers arranged so as to be aligned in the flow direction of air conditioning air in the vehicle interior,
The vehicle interior air conditioning unit includes a damper that accommodates the first and second vehicle interior heat exchangers and changes an air flow rate to the first vehicle interior heat exchanger,
If the air conditioning control device determines that the vehicle exterior heat exchanger is frosted while supplying high-pressure refrigerant to the first and second vehicle interior heat exchangers, the first vehicle interior heat The damper is controlled such that the amount of air blown to the exchanger is reduced as compared with that in the heating operation mode.

  According to this configuration, high heating performance can be obtained by supplying the high-pressure refrigerant to the first and second vehicle interior heat exchangers in the heating operation mode. On the other hand, at the time of the defrosting operation mode, the heat radiation amount is reduced by reducing the amount of air blown to the first vehicle interior heat exchanger, thereby increasing the temperature of the refrigerant supplied to the vehicle exterior heat exchanger, and the defrosting time. Is shortened.

According to a fifth invention, in any one of the first to fourth inventions,
An electric air heater housed in the vehicle interior air conditioning unit;
The air conditioning control device is configured to operate the air heater during the defrosting operation mode.

  According to this configuration, it becomes possible to heat the air for air conditioning by the air heater during the defrosting operation mode. Thereby, the temperature fall of the conditioned air which blows off to a compartment is suppressed.

A sixth invention is the invention according to any one of the first to fourth inventions,
An electric air heater housed in the vehicle interior air conditioning unit;
The air conditioning control device is configured to operate the air heater during the defrosting operation mode.

  According to this configuration, since the amount of air-conditioning air blown is reduced during the defrosting operation mode, it is possible to reduce the amount of low-temperature air that is blown into the passenger compartment, and during the defrosting operation mode. Crew is less likely to feel discomfort.

  According to the first invention, the high-pressure refrigerant can be supplied to the side where the frosting degree of the outdoor heat exchanger is high, so that the refrigerant inlet side and the refrigerant outlet side of the outdoor heat exchanger in the heating operation mode Even if any degree of frost formation of these is high, it can defrost reliably in a short time.

  According to the second invention, the refrigerant superheat degree on the side serving as the refrigerant outlet of the vehicle exterior heat exchanger is obtained in the heating operation mode, and the degree of frost formation is determined based on the superheat degree. The degree of frost can be accurately determined.

  According to the third aspect, the degree of frost formation can be accurately determined by using the air temperature that has passed through the vehicle exterior heat exchanger.

  According to the fourth invention, high heating performance can be obtained by providing the first and second vehicle interior heat exchangers. And since it is made to reduce the ventilation volume to a 1st vehicle interior heat exchanger when the frost is formed in the vehicle exterior heat exchanger, the defrost time by a defrost operation mode can be shortened.

  According to the fifth invention, since the air heater is operated during the defrosting operation mode, it is possible to suppress the temperature drop of the conditioned air blown out to the passenger compartment.

  According to the sixth aspect of the invention, since the air flow rate of the air-conditioning air is reduced during the defrosting operation mode, the amount of low-temperature conditioned air blown out to the passenger compartment during the defrosting operation mode can be reduced, and the passenger feels uncomfortable. It can be hard to feel.

It is a schematic block diagram of the vehicle air conditioner concerning Embodiment 1. FIG. It is a block diagram of a vehicle air conditioner. It is the perspective view which looked at the downstream side vehicle interior heat exchanger from the air flow direction downstream. It is a front view of a vehicle exterior heat exchanger. FIG. 2 is a view corresponding to FIG. 1 when in a heating operation mode. FIG. 2 is a view corresponding to FIG. 1 in the right-side weak defrosting operation mode. FIG. 2 is a view corresponding to FIG. 1 in the right strong defrosting operation mode. FIG. 2 is a view corresponding to FIG. 1 when in a left-side weak defrosting operation mode. FIG. 2 is a view corresponding to FIG. 1 when in a left strong defrosting operation mode. FIG. 2 is a view corresponding to FIG. 1 when in a dehumidifying and heating operation mode. FIG. 2 is a view corresponding to FIG. 1 when in a cooling operation mode. It is a flowchart which shows the control procedure by an air-conditioning control apparatus. It is a flowchart which shows the control procedure when heating operation mode is selected. FIG. 3 is a view corresponding to FIG. 1 according to the second embodiment.

  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.

(Embodiment 1)
FIG. 1 is a schematic configuration diagram of a vehicle air conditioner 1 according to a first embodiment of the present invention. The vehicle on which the vehicle air conditioner 1 is mounted is an electric vehicle including a traveling storage battery and a traveling motor.

  The vehicle air conditioner 1 includes a heat pump device 20, a vehicle interior air conditioning unit 21, and an air conditioning control device 22 (shown in FIG. 2) that controls the heat pump device 20 and the vehicle interior air conditioning unit 21.

  The heat pump device 20 includes an electric compressor (compressor) 30 that compresses a refrigerant, a downstream vehicle interior heat exchanger (first vehicle heat exchanger) 31 disposed in the vehicle interior, and a downstream vehicle in the vehicle interior. An upstream side vehicle interior heat exchanger (second vehicle interior heat exchanger) 32 disposed upstream of the indoor heat exchanger 31 in the air flow direction, a vehicle exterior heat exchanger 33 disposed outside the vehicle interior, An accumulator 34, first to fourth main refrigerant pipes 41 to 44 that connect these devices 30 to 34, first and second branch pipes 45 and 46, and motor-operated valves 52 and 56 that function as expansion valves are provided. ing.

  The electric compressor 30 is a conventionally well-known vehicle-mounted one, and is driven by an electric motor. By changing the rotation speed of the electric compressor 30, the discharge amount per unit time can be changed. The electric compressor 30 is connected to the air conditioning control device 22 so as to be switched between ON and OFF and to control the rotation speed. Electric power is supplied to the electric compressor 30 from the traveling storage battery.

  As shown in FIG. 3, the downstream-side vehicle interior heat exchanger 31 includes an upper header tank 47, a lower header tank 48, and a core 49. The core 49 is formed by integrating tubes 49a and fins 49b extending in the vertical direction alternately in the left-right direction (left-right direction in FIG. 3), and the air for air-conditioning passes between the tubes 49a. ing. The flow direction of the air-conditioning air is indicated by white arrows. The tubes 49a are arranged in two rows in the air flow direction.

  The upper ends of the air flow upstream tube 49 a and the downstream tube 49 a are connected to and communicate with the upper header tank 47. Inside the upper header tank 47, a first partition portion 47a that partitions the upper header tank 47 into an upstream side and a downstream side in the air flow direction is provided. The space upstream of the first partition 47a in the air flow direction communicates with the upper end of the upstream tube 49a, and the space downstream of the first partition 47a in the air flow direction communicates with the upper end of the downstream tube 49a. doing.

  In addition, a second partition portion 47 b that partitions the upper header tank 47 in the left-right direction is provided inside the upper header tank 47. A communication hole 47e is formed on the first partition 47a on the right side of the second partition 47b.

  A refrigerant inflow port 47d is formed on the left side of the upper header tank 47 on the downstream side of the air flow, and a refrigerant outflow port 47c is formed on the upstream side of the air flow.

  Inside the lower header tank 48, similarly to the first partition portion 47 a of the upper header tank 47, a partition portion 48 a that partitions the upstream side and the downstream side in the air flow direction is provided. A space upstream of the partition portion 48a in the air flow direction communicates with the lower end of the upstream tube 49a, and a space downstream of the partition portion 48a in the air flow direction communicates with the lower end of the downstream tube 49a.

  The downstream side vehicle interior heat exchanger 31 has a total of four paths by being configured as described above. That is, the refrigerant flowing in from the inflow port 47d first flows into the space R1 on the downstream side of the first partition 47a of the upper header tank 47 in the air flow direction and on the left side of the second partition 47b. It flows downward in the tube 49a communicating with R1.

  Then, after flowing into the space S1 downstream of the partition 48a of the lower header tank 48 in the air flow direction, flowing to the right and flowing upward in the tube 49a, the first partition of the upper header tank 47 It flows into the space R2 on the downstream side in the air flow direction from 47a and on the right side of the second partition 47b.

  Next, the refrigerant in the space R2 passes through the communication hole 47e of the first partition 47a, is upstream of the first partition 47a of the upper header tank 47 in the air flow direction, and is on the right side of the second partition 47b. It flows into the space R3 and flows downward in the tube 49a communicating with the space R3.

  Then, after flowing into the space S2 upstream of the partition portion 48a of the lower header tank 48 in the air flow direction, flowing to the left side and flowing upward in the tube 49a, the first partition of the upper header tank 47 is reached. The air flows into the space R4 on the upstream side in the air flow direction with respect to the portion 47a and on the left side with respect to the second partition portion 47b, and flows out from the outlet 47c to the outside. Therefore, the downstream-side vehicle interior heat exchanger 31 is arranged in a counterflow so that the refrigerant flows from the downstream side in the air flow direction to the upstream side.

  The upstream vehicle interior heat exchanger 32 is larger in size than the downstream vehicle interior heat exchanger 31 and has the same structure as the downstream vehicle interior heat exchanger 31. As shown in FIG. 1, the upstream side vehicle interior heat exchanger 32 is provided with a first pipe portion C and a second pipe portion D connected to the header tank. Although details will be described later, when the refrigerant flows such that the refrigerant flows into the first pipe portion C of the upstream side passenger compartment heat exchanger 32 and flows out of the second pipe portion D, the upstream side passenger compartment heat exchange is performed. In some cases, the refrigerant flows into the second pipe portion D of the vessel 32 so that the refrigerant flows out from the first pipe portion C.

  The vehicle exterior heat exchanger 33 is disposed in the vicinity of the front end of the motor room in a motor room (corresponding to an engine room in an engine-driven vehicle) provided in the front part of the vehicle so that traveling wind can strike it. As shown in FIG. 4, the vehicle exterior heat exchanger 33 includes an upper header tank 57, a lower header tank 58, and a core 59. The core 59 is obtained by alternately arranging tubes 59a and fins 59b extending in the vertical direction in the left-right direction so that air for air conditioning passes between the tubes 59a.

  The upper end of the tube 59a is connected to and communicates with the upper header tank 57. The lower end of the tube 59a is connected to and communicates with the lower header tank 58.

  Inside the lower header tank 58, a left partition 58a and a right partition 58b for partitioning the inside of the lower header tank 58 in the left-right direction are provided. A left space T1, a central space T2, and a right space T3 are formed inside the lower header tank 58 by the left partition 58a and the right partition 58b.

  On the left side of the lower header tank 58, a left pipe portion A that communicates with the left space T1 is provided. Further, on the right side of the lower header tank 58, a right pipe portion B that communicates with the right space T3 is provided.

  A partition 57a for partitioning the interior of the upper header tank 57 into two in the left-right direction is provided in the center of the upper header tank 57 in the left-right direction. By the partition portion 57a, the left space W1 and the right space W2 are formed inside the upper header tank 57.

  Accordingly, in the exterior heat exchanger 33, the first to fourth paths P1 to P4 are formed in order from the left side to the right side. The first path P1 communicates with the left space T1 of the lower header tank 58 and the left space W1 of the upper header tank 57. The second path P2 communicates with the central space T2 of the lower header tank 58 and the left space W1 of the upper header tank 57. The third path P3 communicates with the central space T2 of the lower header tank 58 and the right space W2 of the upper header tank 57. The fourth path P4 communicates with the right space T3 of the lower header tank 58 and the right space W2 of the upper header tank 57.

  Although details will be described later, in the present embodiment, when the refrigerant flows such that the refrigerant flows into the left pipe portion A of the vehicle exterior heat exchanger 33 and flows out of the right tube portion B, and the vehicle exterior heat exchanger In some cases, the refrigerant flows into the right side pipe part B of 33 and flows so that the refrigerant flows out of the left side pipe part A. When the refrigerant flows into the left pipe portion A, the refrigerant flows in the order of the first path P1, the second path P2, the third path P3, and the fourth path P4. On the other hand, when the refrigerant flows into the right pipe portion B, the refrigerant flows in the order of the fourth path P4, the third path P3, the second path P2, and the first path P1.

  As shown in FIG. 1, a cooling fan 37 is provided in the vehicle. The cooling fan 37 is driven by a fan motor 38 and is configured to blow air to the exterior heat exchanger 33. The fan motor 38 is connected to the air conditioning control device 22 so as to be switched between ON and OFF and to control the rotation speed. Electric power is also supplied to the fan motor 38 from the traveling storage battery. The cooling fan 37 can also blow air to a radiator for cooling a traveling inverter or the like, for example, and can be operated other than when air conditioning is required.

  The first main refrigerant pipe 41 is a pipe that connects the discharge port of the electric compressor 30 and the refrigerant inlet 47d of the downstream side interior heat exchanger 31. The second main refrigerant pipe 42 is a pipe that connects the refrigerant outlet 47 c of the downstream side vehicle interior heat exchanger 31 and the left side pipe portion A of the vehicle exterior heat exchanger 33. The third main refrigerant pipe 43 is a pipe that connects the right pipe part B of the vehicle exterior heat exchanger 33 and the second pipe part D of the upstream vehicle interior heat exchanger 32. The fourth main refrigerant pipe 44 is a pipe that connects the first pipe portion C of the upstream-side vehicle interior heat exchanger 32 and the suction port of the electric compressor 30.

  The first branch pipe 45 branches from the middle part of the second main refrigerant pipe 42 and is connected to the fourth main refrigerant pipe 44. The second branch pipe 46 branches from the side closer to the downstream side interior heat exchanger 31 than the branch point of the first branch pipe 45 in the middle portion of the second main refrigerant pipe 42, and the fourth main refrigerant pipe 44 It is connected to the side closer to the upstream side vehicle interior heat exchanger 32 than the connection point of the one branch pipe 45.

  The accumulator 34 is disposed in the middle of the fourth main refrigerant pipe 44 closer to the suction port of the electric compressor 30 than the connection point of the first branch pipe 45.

  A first solenoid valve 50 is provided in the second main refrigerant pipe 42. The first solenoid valve 50 is located between the branch point of the second branch pipe 46 and the branch point of the first branch pipe 45 in the second main refrigerant pipe 42. The first solenoid valve 50 is controlled by the air conditioning controller 22 so as to switch between an open state in which the passage of the second main refrigerant pipe 42 is opened and a closed state in which the passage is closed.

  A bidirectional motor operated valve 52 is provided in the middle of the third main refrigerant pipe 43. The bidirectional motor operated valve 52 is controlled by the air conditioning control device 22 and can be switched between an open state in which the passage of the third main refrigerant pipe 43 is opened and a closed state in which the passage is closed, and the throttle amount is adjusted in the open state. Can be done. Therefore, the bidirectional electric valve 52 functions as an expansion valve that expands the refrigerant.

  A second electromagnetic valve 53 is provided in the fourth main refrigerant pipe 44. The second electromagnetic valve 53 is located closer to the upstream side interior heat exchanger 32 than the branching point of the first branch pipe 45 in the fourth main refrigerant pipe 44. The second electromagnetic valve 53 is controlled by the air conditioning controller 22 and is configured to switch between an open state in which the passage of the fourth main refrigerant pipe 44 is opened and a closed state in which the passage is closed.

  The first branch pipe 45 is provided with a third electromagnetic valve 54 and a check valve 55 with an orifice. The third solenoid valve 54 is located closer to the second main refrigerant pipe 42 than the check valve 55 with an orifice in the first branch pipe 45. The third solenoid valve 54 is controlled by the air conditioning controller 22 so as to switch between an open state in which the passage of the first branch pipe 45 is opened and a closed state in which the passage is closed.

  The check valve with orifice 55 incorporates an orifice that functions as a throttle. Therefore, the check valve 55 with an orifice functions as an expansion valve for expanding the refrigerant.

  If the desired defrosting performance can be satisfied, a normal check valve without an orifice (no throttle) may be used instead of the check valve 55 with an orifice. In that case, the refrigerant does not expand at the check valve portion, but the refrigerant that has passed through the vehicle exterior heat exchanger 33 is in a gas-liquid two-phase state and the saturation temperature is lowered, and accordingly the refrigerant Therefore, even if the refrigerant flows into the accumulator 34, there is no problem in terms of the pressure resistance of the accumulator 34.

  The check valve 55 with an orifice blocks the flow of the refrigerant from the fourth main refrigerant pipe 44 side to the second main refrigerant pipe 42 side of the first branch pipe 45, and from the second main refrigerant pipe 42 to the fourth main refrigerant pipe 42. The refrigerant is allowed to flow to the refrigerant pipe 44 side.

  A one-way motor operated valve 56 is provided in the middle of the second branch pipe 46. The one-way motor operated valve 56 is controlled by the air conditioning controller 22 and can be switched between an open state in which the passage of the second branch pipe 46 is opened and a closed state in which the passage is closed, and the throttle amount can be adjusted in the open state. It can be done.

  The first to third electromagnetic valves 50, 53, 54, the bidirectional electric valve 52, the check valve 55 with orifice and the one-way electric valve 56 constitute the heat pump device 20.

  The vehicle interior air conditioning unit 21 includes a casing 60 that houses the downstream side vehicle interior heat exchanger 31 and the upstream side vehicle interior heat exchanger 32, an air heater 61 that is accommodated in the casing 60, and an air mix damper (temperature). (Adjustment damper) 62, an air mix damper actuator 63 that drives the air mix damper 62, a blow mode switching damper 64, and a blower 65.

  The blower 65 is for selecting one of the air in the vehicle interior (inside air) and the air outside the vehicle interior (outside air) and blowing it into the casing 60 as air-conditioning air. The blower 65 includes a sirocco fan 65a and a blower motor 65b that rotationally drives the sirocco fan 65a. The blower motor 65b is connected to the air conditioning control device 22 so as to be switched between ON and OFF and to control the rotation speed. Power is also supplied to the blower motor 65b from the traveling storage battery.

  The casing 60 is disposed inside an instrument panel (not shown) in the vehicle interior. The casing 60 is formed with a defroster outlet 60a, a vent outlet 60b, and a heat outlet 60c. These air outlets 60a to 60c are opened and closed by the air outlet mode switching damper 64, respectively. Although not shown, the blow mode switching damper 64 is operated by an actuator connected to the air conditioning control device 22. Examples of the blowing mode include a defroster mode in which conditioned air flows to the defroster outlet 60a, a vent mode in which conditioned air flows to the vent outlet 60b, a heat mode in which conditioned air flows to the heat outlet 60c, a defroster outlet 60a, and a heat blower These include a differential / heat mode in which conditioned air flows to the outlet 60c, a bi-level mode in which conditioned air flows to the vent outlet 60b and the heat outlet 60c.

  The entire amount of the air-conditioning air introduced into the casing 60 passes through the upstream-side vehicle interior heat exchanger 32.

  The air mix damper 62 is accommodated between the upstream side passenger compartment heat exchanger 32 and the downstream side passenger compartment heat exchanger 31 in the casing 60. The air mix damper 62 passes through the upstream vehicle interior heat exchanger 32 by changing the amount of air passing through the downstream vehicle interior heat exchanger 31 among the air that has passed through the upstream vehicle interior heat exchanger 32. This is for adjusting the temperature of the blown air by determining the mixing ratio of the air that has passed through and the air that has passed through the downstream side interior heat exchanger 31.

  The air heater 61 is accommodated on the downstream side of the downstream-side vehicle interior heat exchanger 31 in the casing 60. The air heater 61 can be configured by a PTC heater using a PTC element that generates heat by flowing an electric current, for example. The air heater 61 is connected to the air-conditioning control device 22 so that the ON / OFF switching and the heat generation amount (power supply amount) are controlled. The air heater 61 is also supplied with power from the traveling storage battery.

  Further, the vehicle air conditioner 1 includes an outdoor air temperature sensor 70, an upstream vehicle interior heat exchanger temperature detection sensor 73, a downstream vehicle interior heat exchanger temperature detection sensor 74, a blown air temperature sensor 75, and a left surface. A temperature sensor 83 and a right surface temperature sensor 84 are provided. These sensors 70, 73 to 75, 83, 84 are connected to the air conditioning control device 22.

  The outside air temperature sensor 70 is arranged on the upstream side in the air flow direction with respect to the vehicle exterior heat exchanger 33, and detects the temperature of the external air (outside air temperature TG) before flowing into the vehicle exterior heat exchanger 33. belongs to.

  The blown air temperature sensor 75 is for detecting the temperature of the blown air blown from the casing 60, and is disposed at a predetermined location in the passenger compartment.

  The left surface temperature sensor 83 is for detecting the left surface temperature of the vehicle exterior heat exchanger 33.

  The right surface temperature sensor 84 is for detecting the surface temperature on the right side of the vehicle exterior heat exchanger 33.

  The heat pump device 20 passed through the left side air temperature sensor (exit side air temperature sensor) 81 for detecting the air temperature after passing through the left side of the vehicle exterior heat exchanger 33 and the right side of the vehicle exterior heat exchanger 33. A right-side air temperature sensor (inlet side air temperature sensor) 82 for detecting a later air temperature. The left-side air temperature sensor 81 is displaced downstream in the air flow direction of the vehicle exterior heat exchanger 33 and to the left of the center in the left-right direction of the vehicle exterior heat exchanger 33. The right air temperature sensor 82 is displaced downstream in the air flow direction of the vehicle exterior heat exchanger 33 and to the right of the center in the left-right direction of the vehicle exterior heat exchanger 33. The left air temperature sensor 81 and the right air temperature sensor 82 are connected to the air conditioning control device 22.

  For example, the air conditioning control device 22 sets the operation mode of the heat pump device 20 based on information such as the temperature set by the occupant, the outside air temperature, the vehicle interior temperature, the amount of solar radiation, and the like. Set. Then, the heat pump device 20 is controlled so as to be in the set operation mode, and further, the blower 65 is controlled so as to become the set air volume, and the air mix damper actuator 63 is set so that the air mix damper 62 becomes the set opening degree. It is to be controlled, and is constituted by a known central processing unit, ROM, RAM and the like. Moreover, the electric compressor 30 and the fan motor 38 are controlled according to the load of air conditioning, and the air heater 61 is also controlled as needed.

  In the main routine, the air conditioning control device 22 switches the operation mode of the heat pump device 20, the air volume of the blower 65, the opening of the air mix damper 62, the switching of the blowing mode, The blower motor 65b is controlled. For example, the fan motor 38 basically operates while the electric compressor 30 is in operation, but cooling of the traveling inverter or the like is required even when the electric compressor 30 is stopped. In such a case, it works.

  The operation mode of the heat pump device 20 is a heating operation mode, a right weak defrost operation mode, a right strong defrost operation mode, a left weak defrost operation mode, a left strong defrost operation mode, a dehumidification heating operation mode, and a cooling operation mode. There are types.

  First, the heating operation mode shown in FIG. 5 will be described. The heating operation mode is an operation mode that is selected, for example, when the outside air temperature is lower than 0 ° C. (during extremely low outside air). In the heating operation mode, the downstream vehicle interior heat exchanger 31 and the upstream vehicle interior heat exchanger 32 are used as radiators, and the vehicle exterior heat exchanger 33 is operated as a heat absorber.

  That is, the first solenoid valve 50 and the second solenoid valve 53 are closed. The third solenoid valve 54 is opened. The two-way electric valve 52 is opened so that the refrigerant can be expanded. The one-way motor operated valve 56 is opened.

  When the electric compressor 30 is operated in this state, the high-pressure refrigerant discharged from the electric compressor 30 flows through the first main refrigerant pipe 41 and flows from the inlet 47d of the downstream vehicle interior heat exchanger 31 to the downstream vehicle interior heat exchanger. 31 flows into the downstream-side vehicle interior heat exchanger 31. The refrigerant that has circulated through the downstream-side vehicle interior heat exchanger 31 flows from the second main refrigerant pipe 42 into the second branch pipe 46 through the outlet 47c, passes through the one-way motor-operated valve 56, and passes through the upstream-side vehicle interior heat exchanger. 32 flows from the first pipe portion C into the upstream vehicle interior heat exchanger 32 and circulates through the upstream vehicle interior heat exchanger 32.

  That is, in the heating operation mode, since the high-temperature refrigerant flows into the downstream-side vehicle interior heat exchanger 31 and the upstream-side vehicle interior heat exchanger 32, the air-conditioning air is supplied from the downstream-side vehicle interior heat exchanger 31 and the upstream-side heat exchanger 31. It will be heated by both the vehicle interior heat exchangers 32, and thus a high heating capacity is obtained.

  Further, in the heating operation mode, the refrigerant that has flowed into the downstream-side vehicle interior heat exchanger 31 flows from the downstream side in the air flow direction to the upstream side, so the flow of the refrigerant in the downstream-side vehicle interior heat exchanger 31 is an opposing flow. On the other hand, since the refrigerant flowing into the upstream side vehicle interior heat exchanger 32 flows in the air flow direction, the flow of the refrigerant in the upstream side vehicle interior heat exchanger 32 becomes a parallel flow.

  The refrigerant that has circulated through the upstream side vehicle interior heat exchanger 32 passes through the third main refrigerant pipe 43 through the second pipe portion D, and reaches the bidirectional electric valve 52. Since the bidirectional electric valve 52 is throttled, the refrigerant expands by passing through the bidirectional electric valve 52. The expanded refrigerant flows into the vehicle exterior heat exchanger 33 from the right pipe portion B.

  The refrigerant flowing into the exterior heat exchanger 33 flows in the order of the fourth path P4, the third path P3, the second path P2, and the first path P1 while exchanging heat with the external air, and then flows out from the left pipe portion A.

  In the heating operation mode, the refrigerant inlet side of the vehicle exterior heat exchanger 33 is on the right side, and the refrigerant outlet side is on the left side. Depending on the operating state of the heat pump device 20 and the like, the refrigerant superheat degree on the refrigerant outlet side of the outdoor heat exchanger 33 may be 0 degrees or more. In this case, since it is considered that the refrigerant is completely evaporated in the refrigerant outlet side region of the vehicle exterior heat exchanger 33, frost formation often starts from the refrigerant inlet side (right side) of the vehicle exterior heat exchanger 33.

  On the other hand, the refrigerant superheat degree on the refrigerant outlet side of the exterior heat exchanger 33 may be less than 0 degrees. In this case, the refrigerant is not in a superheated gas state on the refrigerant outlet side of the vehicle exterior heat exchanger 33, and from the refrigerant outlet side (left side) of the vehicle exterior heat exchanger 33 due to a decrease in saturation temperature caused by refrigerant pressure loss. Fretting often begins.

  Therefore, in this embodiment, in the heating operation mode, frost formation starts from the right side that is the refrigerant inlet side of the vehicle exterior heat exchanger 33 and from the left side that is the refrigerant outlet side of the vehicle exterior heat exchanger 33. Sometimes it starts. In addition to these, it is also assumed that frosting starts almost simultaneously over the entire lateral direction of the vehicle exterior heat exchanger 33.

  The refrigerant circulated through the exterior heat exchanger 33 flows into the second branch pipe 45, passes through the third solenoid valve 54 and the check valve 55 with an orifice, passes through the fourth main refrigerant pipe 44, and passes through the accumulator 34. It is sucked into the electric compressor 30.

  Next, the right side weak defrosting operation mode shown in FIG. 6 will be described. In the right-side weak defrosting operation mode, the degree of frost formation on the right side of the vehicle exterior heat exchanger 33 is set to the left as in the case where frost formation starts from the right side that is the refrigerant inlet side of the vehicle exterior heat exchanger 33 in the heating operation mode. This is the operation mode selected when the value is higher than. A method for selecting the operation mode will be described later.

  The right-side weak defrosting operation mode is different from the heating operation mode in that the opening and closing states of the other first to third electromagnetic valves 50, 53, 54 and the one-way motor operated valve 56 are different only in the opening degree of the two-way motor operated valve 52. It is the same as the heating operation mode. The opening degree of the bidirectional electric valve 52 is set larger than the opening degree in the heating operation mode so that the refrigerant passing through the bidirectional electric valve 52 is not expanded.

  Further, the air mix damper actuator 63 of the vehicle interior air conditioning unit 21 is actuated so that the air mix damper 62 is opened and closed so that the air conditioning air flows through the downstream vehicle interior heat exchanger 31.

  In the right-side weak defrosting operation mode, the high-pressure refrigerant that has circulated through the downstream-side vehicle interior heat exchanger 31 and the upstream-side vehicle interior heat exchanger 32 does not expand and passes through the right-side pipe portion B of the vehicle exterior heat exchanger 33 to the outside of the vehicle interior. It flows into the heat exchanger 33. At this time, since the air-conditioning air is being blown into the downstream-side vehicle interior heat exchanger 31, the vehicle is compared with a state where the downstream-side vehicle interior heat exchanger 31 is not blown (right-side strong defrosting operation mode described later). Although the temperature of the refrigerant flowing into the outdoor heat exchanger 33 is lowered, the temperature is high enough to perform defrosting.

  The refrigerant flowing into the exterior heat exchanger 33 flows in the order of the fourth path P4, the third path P3, the second path P2, and the first path P1, and then flows out from the left pipe portion A. When the high-pressure refrigerant flows in from the right side of the vehicle exterior heat exchanger 33, the surface temperature on the right side of the vehicle exterior heat exchanger 33 becomes higher than that on the left side. Therefore, defrosting on the right side of the vehicle exterior heat exchanger 33 is performed quickly.

  Next, the right strong defrosting operation mode shown in FIG. 7 will be described. In the right strong defrosting operation mode, the frosting degree on the right side of the vehicle exterior heat exchanger 33 is set to the left side as in the case where frost formation starts from the right side which is the refrigerant inlet side of the vehicle exterior heat exchanger 33 in the heating operation mode. This is an operation mode that is selected when the amount of frost formation is large compared to.

  In the right-side strong defrosting operation mode, the open / close states of the first to third solenoid valves 50, 53, 54, the bidirectional electric valve 52, and the one-way electric valve 56 are set to be the same as those in the right-side weak defrosting operation mode.

  Further, the air mix damper actuator 63 of the vehicle interior air conditioning unit 21 is operated so that the air mix damper 62 is opened or closed so that air for air conditioning does not flow through the downstream vehicle interior heat exchanger 31.

  In the right-side strong defrosting operation mode, the high-pressure refrigerant that has circulated through the downstream side interior heat exchanger 31 and the upstream side interior heat exchanger 32 does not expand and passes through the right side pipe portion B of the exterior heat exchanger 33 to the outside of the interior of the compartment. It flows into the heat exchanger 33. At this time, since the air-conditioning air is not blown to the downstream-side vehicle interior heat exchanger 31, the temperature of the refrigerant flowing into the vehicle exterior heat exchanger 33 is higher than in the right-side strong defrosting operation mode.

  The refrigerant that has flowed into the exterior heat exchanger 33 flows in the order of the fourth path P4, the third path P3, the second path P2, and the first path P1 and then flows out of the left pipe portion A. Therefore, the exterior heat exchanger 33 The surface temperature on the right side of is higher than that on the left side. The defrosting on the right side of the outside heat exchanger 33 is performed earlier than in the right weak defrosting operation mode.

  Next, the left weak defrosting operation mode shown in FIG. 8 will be described. In the left-side weak defrosting operation mode, the frosting degree on the left side of the vehicle exterior heat exchanger 33 is the right side as in the case where frosting starts from the left side which is the refrigerant outlet side of the vehicle exterior heat exchanger 33 in the heating operation mode. This is the operation mode selected when the value is higher than.

  In the left weak defrosting operation mode, the first electromagnetic valve 50 and the second electromagnetic valve 53 are opened. The third electromagnetic valve 54 is closed. The two-way electric valve 52 is opened so that the refrigerant can be expanded. The one-way motor operated valve 56 is closed.

  Further, the air mix damper actuator 63 of the vehicle interior air conditioning unit 21 is actuated so that the air mix damper 62 is opened and closed so that the air conditioning air flows through the downstream vehicle interior heat exchanger 31.

  In the left weak defrosting operation mode, the high-pressure refrigerant discharged from the electric compressor 30 flows through the first main refrigerant pipe 41 and flows into the downstream vehicle interior heat exchanger 31 from the inlet 47d of the downstream vehicle interior heat exchanger 31. Then, it circulates in the downstream-side vehicle interior heat exchanger 31. The refrigerant circulated through the downstream-side vehicle interior heat exchanger 31 flows into the second main refrigerant pipe 42 through the outlet 47c, and flows into the vehicle exterior heat exchanger 33 from the left pipe portion A through the first electromagnetic valve 50. .

  The refrigerant flowing into the exterior heat exchanger 33 flows in the order of the first pass P1, the second pass P2, the third pass P3, and the fourth pass P4 while exchanging heat with the external air, and then flows out from the right pipe portion B.

  In this way, the high-pressure refrigerant that has circulated only through the downstream side interior heat exchanger 31 flows into the left side of the exterior heat exchanger 33 without expanding. At this time, since the air-conditioning air is being blown into the downstream-side vehicle interior heat exchanger 31, the vehicle is compared with a state where the downstream-side vehicle interior heat exchanger 31 is not blown (left-side strong defrosting operation mode described later). Although the temperature of the refrigerant flowing into the outdoor heat exchanger 33 is lowered, the temperature is high enough to perform defrosting.

  When the high-pressure refrigerant flows in from the left side of the vehicle exterior heat exchanger 33, the surface temperature on the left side of the vehicle exterior heat exchanger 33 becomes higher than that on the right side. Therefore, the defrosting on the left side of the vehicle exterior heat exchanger 33 is performed quickly.

  Next, the left strong defrosting operation mode shown in FIG. 9 will be described. In the left strong defrosting operation mode, the degree of frost formation on the left side of the vehicle exterior heat exchanger 33 is on the right side as in the case where frost formation starts from the left side which is the refrigerant inlet side of the vehicle exterior heat exchanger 33 in the heating operation mode. This is an operation mode that is selected when the amount of frost formation is large compared to.

  In the left strong defrosting operation mode, the open / close states of the first to third electromagnetic valves 50, 53, 54, the bidirectional motor operated valve 52, and the one-way motor operated valve 56 are made the same as in the left weak defrosting operation mode.

  Further, the air mix damper actuator 63 of the vehicle interior air conditioning unit 21 is operated so that the air mix damper 62 is opened or closed so that air for air conditioning does not flow through the downstream vehicle interior heat exchanger 31.

  In the left strong defrosting operation mode, the high-pressure refrigerant that has circulated only through the downstream-side vehicle interior heat exchanger 31 does not expand but flows into the vehicle exterior heat exchanger 33 via the left pipe portion A of the vehicle exterior heat exchanger 33. At this time, since the air-conditioning air is not blown to the downstream side vehicle interior heat exchanger 31, the temperature of the refrigerant flowing into the vehicle exterior heat exchanger 33 is higher than that in the left strong defrosting operation mode.

  The refrigerant that has flowed into the vehicle exterior heat exchanger 33 flows in the order of the first pass P1, the second pass P2, the third pass P3, and the fourth pass P4 and flows out of the right pipe portion B. The surface temperature on the left side becomes higher than that on the right side. The defrosting on the left side of the outside heat exchanger 33 is performed earlier than in the left weak defrosting operation mode.

  Next, the dehumidifying and heating operation mode shown in FIG. 10 will be described. The dehumidifying and heating operation mode is an operation mode selected when, for example, the outside air temperature is 0 ° C. or higher and 25 ° C. or lower. In the dehumidifying and heating operation mode, the downstream-side vehicle interior heat exchanger 31 is used as a radiator, and the upstream-side vehicle interior heat exchanger 32 and the vehicle exterior heat exchanger 33 are operated as heat absorbers.

  That is, the first solenoid valve 50 and the second solenoid valve 53 are closed. The third solenoid valve 54 is opened. The bidirectional motor operated valve 52 is opened so as not to be throttled. The one-way motor-operated valve 56 is opened and throttled to such an extent that the refrigerant can be expanded.

  When the electric compressor 30 is operated in this state, the high-pressure refrigerant discharged from the electric compressor 30 flows through the first main refrigerant pipe 41 and flows from the inlet 47d of the downstream vehicle interior heat exchanger 31 to the downstream vehicle interior heat exchanger. 31 flows into the downstream-side vehicle interior heat exchanger 31. The refrigerant that has circulated through the downstream side vehicle interior heat exchanger 31 flows into the second branch pipe 46 from the second main refrigerant pipe 42 through the outlet 47c, and expands by passing through the one-way electric valve 56. The expanded refrigerant flows from the first pipe portion C of the upstream side vehicle interior heat exchanger 32 into the upstream side vehicle interior heat exchanger 32 and circulates through the upstream side vehicle interior heat exchanger 32.

  The refrigerant that has circulated through the upstream side vehicle interior heat exchanger 32 passes through the third main refrigerant pipe 43 through the second pipe portion D, and reaches the bidirectional electric valve 52. Since the two-way electric valve 52 is not throttled, the refrigerant passes as it is and flows into the vehicle exterior heat exchanger 33 from the right pipe portion B. The refrigerant flowing into the exterior heat exchanger 33 flows out of the left pipe portion A, flows into the second branch pipe 45, passes through the third solenoid valve 54 and the check valve 55 with an orifice, and enters the fourth main refrigerant pipe. 44, and is sucked into the electric compressor 30 through the accumulator 34.

  Next, the cooling operation mode shown in FIG. 11 will be described. The cooling operation mode is an operation mode selected when, for example, the outside air temperature is 25 ° C. or higher. In the cooling operation mode, the upstream-side vehicle interior heat exchanger 32 is used as a heat absorber, and the downstream-side vehicle interior heat exchanger 31 and the vehicle interior heat exchanger 33 are operated as radiators.

  That is, the first electromagnetic valve 50 and the second electromagnetic valve 53 are opened. The third electromagnetic valve 54 is closed. The two-way motor operated valve 52 is opened and throttled to such an extent that the refrigerant can be expanded. The one-way motor operated valve 56 is closed.

  When the electric compressor 30 is operated in this state, the high-pressure refrigerant discharged from the electric compressor 30 flows through the first main refrigerant pipe 41 and flows from the inlet 47d of the downstream vehicle interior heat exchanger 31 to the downstream vehicle interior heat exchanger. 31 flows into the downstream-side vehicle interior heat exchanger 31. The refrigerant that has circulated through the downstream-side vehicle interior heat exchanger 31 flows into the second main refrigerant pipe 42 through the outlet 47c, and flows into the vehicle interior heat exchanger 33 from the left side pipe portion A. The refrigerant that has flowed into the vehicle exterior heat exchanger 33 flows out of the right pipe portion B, passes through the third main refrigerant pipe 43, and expands by passing through the bidirectional electric valve 52. The expanded refrigerant flows from the second pipe portion D of the upstream vehicle interior heat exchanger 32 into the upstream vehicle interior heat exchanger 32 and circulates through the upstream vehicle interior heat exchanger 32.

  The refrigerant that has circulated through the upstream side vehicle interior heat exchanger 32 passes through the first pipe portion C, passes through the fourth main refrigerant pipe 44, and is sucked into the electric compressor 30 through the accumulator 34.

  As shown in FIG. 2, the air conditioning control device 22 determines whether or not frost has adhered to the exterior heat exchanger 33 and the degree of frost formation on the left side or the right side of the exterior heat exchanger 33. It has the frosting determination part 22a which determines whether it is high.

  The method for determining whether or not frost has adhered to the exterior heat exchanger 33 in the frost formation determination unit 22a is as follows. A determination is made based on the outside air temperature TG detected by the outside air temperature sensor 70 and the surface temperature of the vehicle exterior heat exchanger 33 detected by the left surface temperature sensor 83. For example, the outside air temperature TG and the vehicle exterior heat exchanger 33 When the difference from the surface temperature is 10 ° C. or less, it is determined that frost is formed, and when there is a difference larger than 10 ° C., it is determined that frost is not formed. At this time, the determination may be made using the surface temperature of the vehicle exterior heat exchanger 33 detected by the right surface temperature sensor 84. The method for determining frost formation is not limited to the method described above.

  Moreover, in the frost formation determination part 22a, the method of determining which frost formation degree of the left side or the right side of the exterior heat exchanger 33 is high is as follows. After determining that the vehicle exterior heat exchanger 33 is frosted as described above, the temperature detected by the left air temperature sensor 81 and the temperature detected by the right air temperature sensor 82 are compared.

  When the air temperature detected by the left air temperature sensor 81 is lower than the air temperature detected by the right air temperature sensor 82, it is determined that the right side has a higher degree of frost formation than the left side. When the air temperature detected by the left air temperature sensor 81 is higher than the air temperature detected by the right air temperature sensor 82, it is determined that the left side has a higher degree of frost formation than the right side.

  Next, a control procedure by the air conditioning control device 22 will be described based on FIG. FIG. 12 shows the main routine. In step SA1 after the start, the outside air temperature TG detected by the outside air temperature sensor 70 is read. In step SA2 following step SA1, it is determined whether the outside air temperature TG is lower than 0 ° C, 0 ° C or higher and 25 ° C or lower, or higher than 25 ° C.

  If it is determined in step SA2 that the outside air temperature TG is lower than 0 ° C., the process proceeds to step SA3, the heat pump device 20 is switched to the heating operation mode, and the process proceeds to the end of the main routine. In the heating operation mode, the heat mode is mainly selected as the blowing mode of the vehicle interior air conditioning unit 21. Further, the air mix damper 62 is operated so that the temperature of the blown air becomes the target temperature.

  When it is determined in step SA2 that the outside air temperature TG is 0 ° C. or more and 25 ° C. or less, the process proceeds to step SA4, the heat pump device 20 is switched to the dehumidifying / heating operation mode, and the process proceeds to the end of the main routine. If it is determined in step SA2 that the outside air temperature TG is higher than 25 ° C., the process proceeds to step SA5, the heat pump device 20 is switched to the cooling operation mode, and the process proceeds to the end of the main routine.

  In step SA3, the subroutine control at the time of heating operation mode selection shown in FIG. 13 is performed.

  Next, subroutine control when the heating operation mode is selected will be described. In step SB1 after the start, the heating operation is continued. In step SB2 following step SB1, it is determined whether or not the vehicle exterior heat exchanger 33 is frosted. This step SB2 is performed by the frost determination unit 22a of the air conditioning control device 22, and the value when the temperature detected by the left air temperature sensor 81 or the right air temperature sensor 82 is subtracted from the outside air temperature TG is more than 20. If the value is large, it is determined that frost formation has occurred, and the process proceeds to step SB3. On the other hand, when the value is 20 or less, it is determined that frost is not formed, and the process returns to step SB1 to continue the heating operation.

  In step SB3, the degree of frost formation is determined to determine which of the left side and the right side of the exterior heat exchanger 33 has a higher degree of frost formation. This step SB3 is performed by the frost determination unit 22a of the air conditioning control device 22. First, the temperature detected by the left air temperature sensor 81 is compared with the temperature detected by the right air temperature sensor 82. When the air temperature detected by the left air temperature sensor 81 is lower than the air temperature detected by the right air temperature sensor 82, the right side of the vehicle exterior heat exchanger 33 has a higher degree of frost formation than the left side. judge. On the other hand, when the air temperature detected by the left air temperature sensor 81 is higher than the air temperature detected by the right air temperature sensor 82, the left side of the vehicle exterior heat exchanger 33 has a higher degree of frost formation than the right side. judge.

  For example, even when no frost is formed on the right side of the vehicle exterior heat exchanger 33, it is determined that the degree of frost formation on the right side is low. Is determined to be low.

  If it is determined in step SB3 that the right side has a higher degree of frost formation than the left side, the process proceeds to step SB4. In step SB4, the voltage (Vb) of the blower motor 65b is captured. By taking in the voltage (Vb) of the blower motor 65b, the amount of blown air can be obtained indirectly.

  Then, it progresses to step SB5 and it is determined whether the voltage (Vb) of the ventilation motor 65b is higher than V1. The determination reference value V1 is a value by which it can be determined whether or not the passenger desires strong heating. That is, when strong heating is desired, the air-conditioning control device 22 controls the voltage (Vb) of the blower motor 65b to be higher than V1 in order to obtain a large air volume. Is controlled by the air conditioning controller 22 so that the voltage (Vb) of the blower motor 65b is equal to or lower than V1.

  And when it determines with YES by step SB5 and the voltage (Vb) of the ventilation motor 65b is higher than V1, it progresses to step SB6, the right weak defrosting operation mode is selected, and the heat pump apparatus 20 and vehicle interior air conditioning unit 21 is controlled by the air conditioning controller 22 so as to be in the right-side weak defrosting operation mode.

  In this right-side weak defrosting operation mode, since the high-pressure refrigerant flows from the right side of the vehicle exterior heat exchanger 33, the surface temperature on the right side of the vehicle exterior heat exchanger 33 rises compared to the left side, The right side of the vehicle exterior heat exchanger 33 can be defrosted early and reliably. In addition, the left side of the vehicle exterior heat exchanger 33 is also defrosted.

  Moreover, since the ventilation to the downstream vehicle interior heat exchanger 31 is continued in the right-side weak defrosting operation mode, the deterioration of the heating performance is minimized.

  In step SB7 following step SB6, the air heater 61 is turned on to heat the air-conditioning air. Thereby, the temperature of the conditioned air blown out to the passenger compartment can be increased.

  In step SB8 following step SB7, the voltage (Vb) of the blower motor 65b is decreased by 0.5V. Thereby, the quantity of the conditioned air which blows off into the passenger compartment decreases. The degree of decrease in the voltage (Vb) of the blower motor 65b is not limited to 0.5V, and can be set arbitrarily.

  Subsequently, it progresses to step SB9, and it is determined whether the defrosting of the vehicle exterior heat exchanger 33 was completed. As the defrosting determination in step SB9, for example, using a timer, it is determined that the defrosting is completed when a predetermined time (for example, 1 minute) has elapsed since the start of the right weak defrosting operation mode. Alternatively, the determination may be made based on the difference between the outside air temperature TG and the air temperature that has passed through the vehicle exterior heat exchanger 33.

  When it is determined as YES in Step SB9 and the defrosting of the vehicle exterior heat exchanger 33 is completed, the process proceeds to the end, and when it is determined as NO and the defrosting of the vehicle exterior heat exchanger 33 is not completed. In step SB6, the right weak defrosting operation mode is continued.

  When it is determined NO in step SB5 and the voltage (Vb) of the blower motor 65b is V1 or less, the process proceeds to step SB10 to select the right strong defrosting operation mode, and the heat pump device 20 and the vehicle interior air conditioning unit 21 are It is controlled by the air conditioning control device 22 so as to be in the right strong defrosting operation mode.

  In this right-side strong defrosting operation mode, air is not sent to the downstream-side vehicle interior heat exchanger 31, that is, the amount of air blown to the downstream-side vehicle interior heat exchanger 31 is lower than that in the heating operation mode. As a result, the temperature of the high-pressure refrigerant flowing from the right side of the vehicle exterior heat exchanger 33 becomes higher than that in the right-side weak defrosting operation mode, so that the right side of the vehicle exterior heat exchanger 33 can be moved more quickly and reliably. It becomes possible to defrost.

  Next, the process proceeds to step SB11, where it is determined whether or not the defrosting of the vehicle exterior heat exchanger 33 is completed. If the defrosting of the vehicle exterior heat exchanger 33 is completed, the process proceeds to the end, and the defrosting is completed. If not, the process returns to step SB10 and the right strong defrosting operation mode is continued.

  When it is determined in step SB3 that the left side has a higher degree of frost formation than the right side, the process proceeds to step SB12. In step SB12, the voltage (Vb) of the blower motor 65b is taken in the same manner as in step SB4.

  Thereafter, the process proceeds to step SB13, and the same determination as in step SB5 is performed. When it is determined YES in step SB13 and the voltage (Vb) of the blower motor 65b is higher than V1, the process proceeds to step SB14 to select the left weak defrosting operation mode, and the heat pump device 20 and the vehicle interior air conditioning unit 21 are It is controlled by the air conditioning control device 22 so as to be in the left-side weak defrosting operation mode.

  In this left-side weak defrosting operation mode, since the high-pressure refrigerant flows from the left side of the vehicle exterior heat exchanger 33, the surface temperature on the left side of the vehicle exterior heat exchanger 33 rises compared to the right side, It becomes possible to defrost the left side of the exterior heat exchanger 33 early and reliably. In addition, the right side of the vehicle exterior heat exchanger 33 is also defrosted.

  Moreover, since the ventilation to the downstream side vehicle interior heat exchanger 31 is continued in the left-side weak defrosting operation mode, the deterioration of the heating performance is minimized.

  In step SB15 following step SB14, the air heater 61 is turned on to heat the air-conditioning air. In step SB16 following step SB15, the voltage (Vb) of the blower motor 65b is decreased by 0.5V. The degree of decrease in the voltage (Vb) of the blower motor 65b is not limited to 0.5V, and can be set arbitrarily.

  Next, the process proceeds to step SB17, where the same determination as in step SB9 is performed. When the defrosting of the vehicle exterior heat exchanger 33 is completed, the process proceeds to the end, and the defrosting of the vehicle exterior heat exchanger 33 is not completed. In that case, the process returns to step SB14 and the left weak defrosting operation mode is continued.

  When it is determined NO in step SB13 and the voltage (Vb) of the blower motor 65b is equal to or lower than V1, the process proceeds to step SB18 to select the left strong defrosting operation mode, and the heat pump device 20 and the vehicle interior air conditioning unit 21 are It is controlled by the air conditioning control device 22 so as to be in the left side strong defrosting operation mode.

  In the left strong defrosting operation mode, the air is not sent to the downstream side interior heat exchanger 31, that is, the amount of air blown to the downstream side interior heat exchanger 31 is lower than that in the heating operation mode. As a result, the temperature of the high-pressure refrigerant flowing from the left side of the vehicle exterior heat exchanger 33 becomes higher than that in the left-side weak defrosting operation mode, so that the left side of the vehicle exterior heat exchanger 33 can be made even earlier and more reliably. It becomes possible to defrost.

  And it progresses to step SB19, the same determination as step SB11 is performed, and when defrosting of the vehicle exterior heat exchanger 33 is completed, it progresses to an end and defrosting of the vehicle exterior heat exchanger 33 is completed. If not, the process returns to step SB18 and the left strong defrosting operation mode is continued.

  As described above, according to the vehicle air conditioner 1 according to the first embodiment, when the degree of frost formation on the right side that is the refrigerant inlet side of the vehicle exterior heat exchanger 33 is high in the heating operation mode, Switch to defrosting operation mode or right-side strong defrosting operation mode. And a high pressure refrigerant | coolant is supplied to the location (right side pipe part B) which was a refrigerant | coolant inlet_port | entrance at the time of the heating operation mode in the vehicle exterior heat exchanger 33. FIG.

  On the other hand, when the degree of frost formation on the left side, which is the refrigerant outlet side of the outdoor heat exchanger 33 in the heating operation mode, is high, the mode is switched to the left weak defrosting operation mode or the left strong defrosting operation mode. And a high pressure refrigerant | coolant is supplied to the location (left side pipe part A) which was a refrigerant | coolant exit at the time of the heating operation mode in the exterior heat exchanger 33. FIG.

  Thus, since the high-pressure refrigerant can be supplied to the side where the degree of frost formation of the vehicle exterior heat exchanger 33 is high, either the refrigerant inlet side or the refrigerant outlet side of the vehicle exterior heat exchanger 33 in the heating operation mode. Even if the degree of frost formation is high, defrosting can be performed reliably in a short time.

  In addition, when the degree of frost formation on the refrigerant inlet side in the heating operation mode in the exterior heat exchanger 33 is high, the efficiency of heat exchange on the inlet side is reduced and the air temperature is higher than that on the outlet side. On the other hand, when the degree of frost formation on the refrigerant outlet side in the heating operation mode in the exterior heat exchanger 33 is high, the efficiency of heat exchange on the outlet side is reduced and the air temperature is higher than that on the inlet side. In this embodiment, a left air temperature sensor 81 and a right air temperature sensor 82 are provided to detect the air temperature after passing through the left side of the vehicle exterior heat exchanger 33 and the air temperature passing through the right side, and Since the degree of frost formation is determined, it is possible to accurately determine which side of the vehicle exterior heat exchanger 33 has the higher degree of frost formation.

  In the heating operation mode, high heating performance can be obtained by supplying high-pressure refrigerant to the downstream side and upstream side vehicle interior heat exchangers 31 and 32. On the other hand, in the right strong defrosting operation mode or the left strong defrosting operation mode, the amount of heat released is reduced by reducing the amount of air blown to the downstream side interior heat exchanger 31. Thereby, the temperature of the refrigerant | coolant supplied to the vehicle exterior heat exchanger 33 can be raised, and defrost time can be shortened further.

  In addition, air conditioning air is heated by the air heater 61 during the right weak defrosting operation mode or the left weak defrosting operation mode. Thereby, the temperature fall of the conditioned air which blows off to a vehicle interior can be suppressed.

In addition, since the amount of air-conditioning air blown in the right-side weak defrosting operation mode or the left-side weak defrosting operation mode is reduced, the amount of low-temperature air that blows out into the passenger compartment can be reduced. The passenger is less likely to feel uncomfortable during the defrosting operation mode.
(Embodiment 2)
FIG. 14 is a schematic configuration diagram of the vehicle air conditioner 1 according to the second embodiment of the present invention. The second embodiment is the same as the first embodiment except that the determination method in the frosting determination unit 22a is different from that of the first embodiment. Hereinafter, a different part from Embodiment 1 is demonstrated in detail.

  The heat pump device 20 is provided with a low-pressure side refrigerant pressure detection sensor 85 and an outlet-side temperature sensor 86. The low-pressure side refrigerant pressure detection sensor 85 is for detecting the refrigerant pressure on the low-pressure side of the heat pump device 20, and is located on the side of the second main refrigerant pipe 42 close to the outdoor heat exchanger 33. The low-pressure side refrigerant pressure detection sensor 85 detects the refrigerant pressure in the vicinity of the left pipe portion A.

  The outlet-side temperature sensor 86 is for detecting the temperature of the refrigerant flowing through the refrigerant outlet-side pipe in the heating operation mode in the vehicle exterior heat exchanger 33, and similarly to the low-pressure side refrigerant pressure detection sensor 81, The second main refrigerant pipe 42 is located on the side close to the vehicle exterior heat exchanger 33. The outlet side temperature sensor 86 detects the refrigerant pressure in the vicinity of the left pipe portion A.

  The low-pressure side refrigerant pressure detection sensor 85 and the outlet-side temperature sensor 86 are connected to the air conditioning control device 22.

  In the frosting determination unit 22a, whether or not frost is attached to the vehicle exterior heat exchanger 33 is determined in the same manner as in the first embodiment, on the left side or right side of the vehicle exterior heat exchanger 33. A method for determining whether the degree of frost formation is high is as follows.

  That is, the frost determination unit 22a constitutes a refrigerant superheat degree calculation means for calculating the refrigerant superheat degree based on the pressure detected by the low pressure side refrigerant pressure detection sensor 85 and the temperature detected by the outlet side temperature sensor 86. . If the calculated refrigerant superheat degree is equal to or greater than 0 degrees, the frost formation determination unit 22a determines that the refrigerant inlet side in the heating operation mode in the vehicle exterior heat exchanger 33 has a higher degree of frost formation than the outlet side. On the other hand, if the calculated degree of refrigerant superheat is less than 0 degree, it is determined that the refrigerant outlet side in the heating operation mode in the exterior heat exchanger 33 has a higher degree of frost formation than the inlet side.

  If the degree of refrigerant superheating on the refrigerant outlet side of the vehicle exterior heat exchanger 33 is 0 degree or more, it is determined that the refrigerant has completely evaporated in the region of the refrigerant outlet side of the vehicle exterior heat exchanger 33. In this case, it is estimated that frosting starts from the refrigerant inlet side of the vehicle exterior heat exchanger 33. Therefore, in this case, the determination of the degree of frost formation is accurately performed by determining that the degree of frost formation on the refrigerant inlet side in the heating operation mode in the exterior heat exchanger 33 is high.

  Further, the fact that the degree of refrigerant superheating on the refrigerant outlet side of the vehicle exterior heat exchanger 33 is less than 0 degrees means that the refrigerant is not in the superheated gas state on the exit side of the vehicle exterior heat exchanger 33. In this case, it is estimated that frosting starts from the refrigerant outlet side of the vehicle exterior heat exchanger 33 due to a decrease in saturation temperature caused by refrigerant pressure loss. Therefore, in this case, the determination of the degree of frost formation is accurately performed by determining that the degree of frost formation on the refrigerant outlet side in the heating operation mode in the exterior heat exchanger 33 is high.

  Therefore, the vehicular air conditioner 1 according to the second embodiment can achieve the same effects as those of the first embodiment.

  Further, since the degree of refrigerant superheating on the side (right side) serving as the refrigerant outlet of the vehicle exterior heat exchanger 33 in the heating operation mode is obtained and the degree of frost formation is determined based on the degree of superheat, the degree of frost formation Can be accurately determined.

  Moreover, in the said embodiment, although switching to the dehumidification heating operation mode is enabled as an operation mode of the heat pump apparatus 20, it is not restricted to this, You may eliminate dehumidification heating operation mode.

  Moreover, although the said embodiment demonstrated the case where the vehicle air conditioner 1 was mounted in an electric vehicle, it is not restricted to this, For example, the vehicle air conditioner 1 is mounted in the hybrid vehicle provided with the engine and the motor for driving | running | working. It is also possible.

  As described above, the vehicle air conditioner according to the present invention can be mounted on, for example, an electric vehicle or a hybrid vehicle.

DESCRIPTION OF SYMBOLS 1 Vehicle air conditioner 20 Heat pump apparatus 21 Car interior air conditioning unit 22 Air conditioning control apparatus 22a Frosting judgment part 30 Electric compressor (compressor)
31 Downstream passenger compartment heat exchanger (first passenger compartment heat exchanger)
32 Upstream vehicle interior heat exchanger (second vehicle interior heat exchanger)
33 Outside heat exchangers 41 to 44 First to fourth main refrigerant pipes 61 Air heater 62 Air mix damper 65 Blower 81 Left side air temperature sensor (outlet side air temperature sensor)
82 Right side air temperature sensor (inlet side air temperature sensor)
85 Low pressure side refrigerant pressure detection sensor 86 Outlet side temperature sensor

Claims (6)

A compressor that compresses the refrigerant; a vehicle interior heat exchanger disposed in the vehicle interior; a vehicle exterior heat exchanger disposed outside the vehicle interior; and an expansion valve; and the compressor, the vehicle interior heat A heat pump device in which the exchanger, the expansion valve, and the exterior heat exchanger are connected by a refrigerant pipe;
A vehicle interior air conditioning unit configured to house the vehicle interior heat exchanger and to have a blower that blows air for air conditioning in the vehicle interior heat exchanger and to generate conditioned air and supply the conditioned air to the vehicle interior; ,
An air conditioner for a vehicle comprising an air conditioning control device for controlling the heat pump device,
The air conditioning control device includes an operation mode of the heat pump device, a heating operation mode in which the vehicle interior heat exchanger is a radiator, and the vehicle exterior heat exchanger is a heat absorber, and a high pressure refrigerant in the vehicle exterior heat exchanger. And switching between a plurality of operation modes including a defrosting operation mode in which defrosting is performed and defrosting between the refrigerant inlet side and the refrigerant outlet side in the heating operation mode in the vehicle exterior heat exchanger. It has a frosting determination unit that individually obtains the degree of frost,
When the frosting determination unit determines that the refrigerant inlet side in the heating operation mode of the vehicle exterior heat exchanger has a higher degree of frost formation than the refrigerant outlet side, the air conditioning control device in the vehicle exterior heat exchanger While supplying high-pressure refrigerant to the location that was the refrigerant inlet in the heating operation mode, when the frosting determination unit has a higher degree of frost formation on the refrigerant outlet side in the heating operation mode in the vehicle exterior heat exchanger than the refrigerant inlet side When judged, the vehicle air conditioner is configured to supply high-pressure refrigerant to a location that was a refrigerant outlet in the heating operation mode in the vehicle exterior heat exchanger. In the vehicle air conditioner according to claim 1,
The frosting determination unit constitutes refrigerant superheat degree calculation means for calculating the refrigerant superheat degree on the refrigerant outlet side in the vehicle exterior heat exchanger of the heat pump device, and the refrigerant calculated by the refrigerant superheat degree calculation means If the degree of superheat is 0 degree or more, it is determined that the refrigerant inlet side in the heating operation mode in the vehicle exterior heat exchanger has a higher degree of frost formation than the refrigerant outlet side, while if the refrigerant superheat degree is less than 0 degree. A vehicle air conditioner configured to determine that the refrigerant outlet side in the heating operation mode in the vehicle exterior heat exchanger has a higher degree of frost formation than the refrigerant inlet side. In the vehicle air conditioner according to claim 1,
An inlet side air temperature sensor for detecting an air temperature after passing through the refrigerant inlet side in the heating operation mode in the vehicle exterior heat exchanger;
An outlet side air temperature sensor for detecting an air temperature after passing through the refrigerant outlet side in the heating operation mode in the vehicle exterior heat exchanger,
When the air temperature detected by the inlet-side air temperature sensor is lower than the air temperature detected by the outlet-side air temperature sensor, the frosting determination unit is in the heating operation mode in the vehicle exterior heat exchanger. If the refrigerant outlet side determines that the degree of frost formation is higher than the refrigerant inlet side, and the air temperature detected by the inlet side air temperature sensor is higher than the air temperature detected by the outlet side air temperature sensor, the vehicle A vehicle air conditioner configured to determine that the refrigerant inlet side in the heating operation mode of the outdoor heat exchanger has a higher degree of frost formation than the refrigerant outlet side. In the vehicle air conditioner according to any one of claims 1 to 3,
The heat pump device includes first and second vehicle interior heat exchangers arranged so as to be aligned in the flow direction of air conditioning air in the vehicle interior,
The vehicle interior air conditioning unit includes a damper that accommodates the first and second vehicle interior heat exchangers and changes an air flow rate to the first vehicle interior heat exchanger,
If the air conditioning control device determines that the vehicle exterior heat exchanger is frosted while supplying high-pressure refrigerant to the first and second vehicle interior heat exchangers, the first vehicle interior heat An air conditioner for a vehicle, wherein the damper is controlled so that the amount of air blown to the exchanger is reduced as compared with that in the heating operation mode. In the vehicle air conditioner according to any one of claims 1 to 4,
An electric air heater housed in the vehicle interior air conditioning unit;
The vehicle air conditioner is configured to operate the air heater in the defrosting operation mode. In the vehicle air conditioner according to any one of claims 1 to 4,
The vehicle air conditioner is characterized in that the air conditioning control device controls the vehicle interior air conditioning unit so that an air blowing amount of the air conditioning air in the defrosting operation mode is lower than an air blowing amount in the heating operation mode.

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