On-vehicle air conditioner

Abstract

To suppress generation of coolant passing noise.SOLUTION: An on-vehicle air conditioner comprises: a refrigeration cycle device; a sensor for detecting a post-evaporation temperature that is a temperature at a downstream end of an evaporator in an air flowing direction in the refrigeration cycle device; a heater core and an FSV for switching between presence and absence of cooling water supply to the heater core, which are provided in a cooling water circuit of an engine cooling device; an air-conditioning case for making air-conditioning air pass through the evaporator and selectively pass through the heater core, to send the air-conditioning air into the cabin; and a controller. The controller sets a target blowout temperature of air-conditioned air, and sets a post-evaporation temperature target that is a target temperature of post-evaporation temperature from the target blowout temperature, and controls a compressor of the refrigeration cycle device on the basis of the post-evaporation temperature and the post-evaporation temperature target. In the controller, the post-evaporation temperature target is set to be lower in a certain range of the target blowout temperature in the case of satisfying predetermined conditions where the FSV is closed and coolant passing noise of the refrigeration cycle device is easy to be recognized by an occupant, as compared to cases when these conditions are not met.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an in-vehicle air conditioner, and more particularly to a control device (controller) for a compressor of a refrigeration cycle device. [Background technology]

[0002] An air conditioner is installed in a vehicle. The air conditioner includes a refrigeration cycle device. In the refrigeration cycle device, when a gas-liquid two-phase refrigerant flows through a refrigerant flow passage where a liquid refrigerant is supposed to flow, unintended vibrations may occur, resulting in refrigerant passing noise. This refrigerant passing noise is likely to occur when the amount of refrigerant discharged from the compressor is small. If passengers recognize the refrigerant passing noise as noise, there is a risk that the comfort inside the vehicle cabin will be impaired, and therefore countermeasures have been considered for some time.

[0003] Patent Document 1 discloses a vehicle air conditioner including a heat pump system and a PTC heater for assisting the heating of air blown by the heat pump system. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2021-109614 A Summary of the Invention [Problem to be solved by the invention]

[0005] An evaporator of a refrigeration cycle device and a heater core of an engine cooling device are arranged inside the air conditioning case of the air conditioner. The evaporator has a function of cooling and dehumidifying the conditioned air. The heater core has a function of heating the conditioned air by being supplied with engine cooling water. The conditioned air sent out from the blower passes through the evaporator, and then selectively passes through the heater core before being blown into the vehicle cabin.

[0006] The engine cooling device is equipped with an FSV (flow shutting valve) that switches between supplying and not supplying cooling water to the heater core. During cooling, the air conditioner is controlled to close the FSV to stop the supply of cooling water to the heater core so that the conditioned air is not heated by the heater core. The air conditioner is controlled by FSV power saving control that relatively reduces the air cooling performance of the evaporator. In other words, since the conditioned air is not heated by the heater core, it is easy to obtain conditioned air with a desired cool target blowing temperature (the target temperature of the conditioned air blown into the vehicle cabin) even if the air cooling performance of the evaporator is reduced, so the refrigeration cycle device is operated with reduced power to reduce power consumption.

[0007] In a refrigeration cycle device, a sensor detects the post-evaporator temperature, which is the temperature at the downstream end of the evaporator in the air flow direction. The air conditioner ECU (an example of a controller) controls the compressor so that the post-evaporator temperature approaches the post-evaporator temperature target (target temperature of the post-evaporator temperature). In the FSV power saving control, this post-evaporator temperature target is set relatively high, which reduces the compressor output and reduces the air cooling performance of the evaporator.

[0008] In this way, in the FSV power saving control, the compressor output is relatively low, and the amount of refrigerant discharged from the compressor is relatively small. Therefore, in the FSV power saving control, there is a problem that the refrigerant passing sound is likely to occur in the refrigeration cycle device. If the passenger recognizes the refrigerant passing sound as noise, the comfort in the vehicle cabin may be impaired.

[0009] Therefore, an object of the present invention is to provide an in-vehicle air conditioner that can suppress the generation of refrigerant passing noise during FSV power saving control (air conditioning control when the FSV is closed). [Means for solving the problem]

[0010] The vehicle air conditioner according to the present invention includes a compressor for compressing a refrigerant circulating in a refrigeration cycle device, a condenser for condensing the gas-phase refrigerant compressed by the compressor, an expansion valve for expanding the liquid-phase refrigerant condensed by the condenser, an evaporator for evaporating the liquid-phase refrigerant by heat exchange between the liquid-phase refrigerant expanded by the expansion valve and conditioned air provided in a vehicle cabin, a sensor for detecting a post-evaporator temperature, which is a temperature at a downstream end of the evaporator in the air flow direction, and a refrigerant pipe connecting the compressor, the condenser, the expansion valve, and the evaporator and through which the refrigerant flows. The vehicle air conditioner also includes a heater core and an FSV (shutoff valve) for switching on and off the supply of the coolant to the heater core, which are provided in a coolant circuit for coolant circulating in an engine cooling device. The vehicle air conditioner further includes an air conditioning case that houses the evaporator and the heater core and sends the conditioned air from a blower into the vehicle cabin by passing the conditioned air through the evaporator and selectively passing the conditioned air through the heater core, and a controller that controls air conditioning operation. The controller sets a target outlet temperature that is a target temperature of the conditioned air to be blown into the vehicle cabin, sets a post-evaporator temperature target that is a target temperature of the post-evaporator temperature based on the target outlet temperature, and controls the compressor so that the post-evaporator temperature approaches the post-evaporator temperature target. When the FSV is in a closed state (when the FSV is in a closed state, the post-evaporator temperature target is set relatively high and the compressor can operate at a relatively low output) and predetermined conditions are met that make the refrigerant passing sound of the refrigeration cycle device easily noticeable to occupants in the vehicle cabin, the controller sets the post-evaporator temperature target lower within a certain range of the target blowing temperature (to increase the output of the compressor and suppress the refrigerant passing sound) compared to when this is not the case.

[0011] In the vehicle air conditioner according to the present invention, the predetermined condition may include a state in which the vehicle in which the air conditioner is mounted is stopped.

[0012] In the vehicle air conditioner according to the present invention, the predetermined condition may include a state in which a single-seat concentrated airflow is executed in which the conditioned air is blown to only one seat in the vehicle cabin or preferentially to that seat, thereby causing an output level of the blower to be relatively low. When the single-seat concentrated airflow is executed while the vehicle is stopped, the controller may set the post-evaporator temperature target lower within a certain range including a lower temperature of the target blowing temperature (and increase the output of the compressor to suppress refrigerant passing noise) compared to when the single-seat concentrated airflow is not executed. Effect of the Invention

[0013] According to the present invention, it is possible to suppress the generation of refrigerant passing noise during FSV power saving control. [Brief description of the drawings]

[0014] [Figure 1] 1 is a diagram showing a schematic configuration of an in-vehicle air conditioning device; [Diagram 2] FIG. 2 is a block diagram showing functional elements of an air conditioner ECU. [Diagram 3] 4 is a flowchart showing a process performed by an air conditioner. [Figure 4] FIG. 4 is a diagram for explaining a post-evaporator temperature target in FSV power saving control. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiment described here. The same elements in all the drawings are given the same reference numerals, and duplicated explanations will be omitted.

[0016] <General configuration of air conditioner> FIG. 1 is a diagram showing a schematic configuration of an air conditioner 10. The air conditioner 10 is mounted on a vehicle. The vehicle is, for example, an automobile equipped with a gasoline-driven engine. However, the vehicle may also be a hybrid automobile equipped with both an engine and a driving motor. The air conditioner 10 is a device that adjusts the temperature and humidity of the air taken in and blows it out into the vehicle cabin. In other words, the air conditioner 10 is a device that performs air conditioning operations such as cooling, dehumidification, and heating.

[0017] The air conditioner 10 includes a blower unit 60 that blows air, a refrigeration cycle device 30 that cools and dehumidifies the air, and a heater core 59 that heats the air. The blower unit 60 includes an air conditioning case 61 and a blower 62. The air conditioning case 61 includes an inside air intake port 71 and an outside air intake port 72. An inside / outside air switching door 73 that switches between opening and closing the inside air intake port 71 and the outside air intake port 72 is provided inside the air conditioning case 61.

[0018] The blower 62 is provided inside the air conditioning case 61. The blower 62 is an electric blower whose rotation speed can be controlled using an electric motor. The blower 62 is a centrifugal blower, and is disposed so as to blow air taken in from the intake ports 71, 72 toward the evaporator 42. The blower 62 is also called a blower.

[0019] The refrigeration cycle device 30 includes an evaporator 42. The evaporator 42 is a device for evaporating a liquid-phase refrigerant into a gas-phase refrigerant. The evaporator 42 is a heat exchanger that removes heat from the surroundings when evaporating the refrigerant. That is, the evaporator 42 is a heat exchanger for cooling and dehumidifying air during air conditioning operation. Inside the air conditioning case 61, the evaporator 42 is located upstream of the heater core 59 in the air flow direction.

[0020] The heater core 59 is a part of the engine cooling device 50. The heater core 59 heats the conditioned air by circulating high-temperature engine cooling water inside.

[0021] The air conditioning case 61 includes a defroster passage 66df, a face passage 66fc, a foot passage 66ft, and a rear seat passage 66rs. The defroster passage 66df is a passage leading to a defroster outlet 70df that blows conditioned air toward the windshield. The face passage 66fc is a passage leading to face outlets 70fc_d, 70fc_p that blow conditioned air toward the upper body including the face of the occupant. The foot passage 66ft is a passage leading to foot outlets 70ft_d, 70ft_p that blow conditioned air toward the lower body including the feet of the occupant. The rear seat passage 66rs is a passage leading to a rear seat outlet 70rs that blows conditioned air toward the rear seat.

[0022] The air outlets 70fc_d and 70ft_d are air outlets on the driver's seat side, and the air outlets 70fc_p and 70ft_p are air outlets on the passenger's seat side.

[0023] An air mix door 64 is provided inside the air conditioning case 61. The air mix door 64 is a door that adjusts the ratio of air that has passed through the evaporator 42 to flow to the heater core 59. A defroster door 68df, a face door 68fc, a foot door 68ft, and a rear seat door 68rs are provided inside the air conditioning case 61. The defroster door 68df is a door that controls the opening and closing of the defroster passage 66df. The face door 68fc is a door that controls the opening and closing of the face passage 66fc. The foot door 68ft is a door that controls the opening and closing of the foot passage 66ft. The rear seat door 68rs is a door that controls the opening and closing of the rear seat passage 66rs.

[0024] The air conditioner 10 is provided with a selection door (not shown) downstream of the face passage 66fc so that the face air outlet 70fc_d on the driver's side and the face air outlet 70fc_p on the passenger's side can be selectively opened and closed. Similarly, the air conditioner 10 is provided with a selection door (not shown) downstream of the foot passage 66ft so that the foot air outlet 70ft_d on the driver's side and the foot air outlet 70ft_p on the passenger's side can be selectively opened and closed.

[0025] The refrigeration cycle device 30 includes an evaporator 42, a compressor 34, a condenser 38, an expansion valve 36, and a refrigerant pipe 32. The compressor 34 is a device that compresses gas-phase refrigerant to a high-temperature, high-pressure state. The compressor 34 is a variable-capacity compressor that can change the compression capacity. When the compressor 34 is in a driving state, the amount of refrigerant circulating through the refrigeration cycle device 30 can be adjusted by changing the compression capacity of the compressor 34. By increasing the compression capacity of the compressor 34, the amount of refrigerant circulating through the refrigeration cycle device 30 can be increased.

[0026] The condenser 38 is a heat exchanger that exchanges heat with outdoor air. The condenser 38 is a heat exchanger that condenses the gas-phase refrigerant into a liquid-phase refrigerant by releasing heat to the outdoor air to reduce the energy of the refrigerant. A condenser fan 40 is provided facing the condenser 38. The condenser fan 40 is intended to promote heat exchange between the outdoor air and the refrigerant by supplying outdoor air around the condenser 38.

[0027] The expansion valve 36 expands the liquid-phase refrigerant flowing into the evaporator 42 to make it easier for the liquid-phase refrigerant to evaporate in the evaporator 42. The expansion valve 36 reduces the pressure of the refrigerant.

[0028] The refrigerant piping 32 connects the compressor 34, the condenser 38, the expansion valve 36, and the evaporator 42, and provides a refrigerant flow path through which the refrigerant circulates.

[0029] Fins 43 are provided at the downstream end (downstream end) of the evaporator 42 in the air flow direction. The air conditioner 10 includes a temperature sensor 45 that uses the fins 43 to detect a post-evaporator temperature, which is the temperature at the downstream end of the evaporator 42 in the air flow direction. As will be described in detail later, the air conditioner 10 also includes an air conditioner ECU 12 (see FIG. 2) and various sensors that detect the outside air temperature, the inside air temperature, the amount of solar radiation, etc.

[0030] <Engine cooling system> As shown in FIG. 1, engine cooling device 50 is a device that supplies cooling water to engine 57 mounted on a vehicle to cool engine 57, cools cooling water warmed by heat from engine 57 and the like using radiator 54, and exchanges heat between the warmed cooling water and conditioned air in heater core 59.

[0031] The engine cooling system 50 includes a water pump 56, a radiator 54, an oil cooler 53, an FSV (flow shutting valve) 58, a heater core 59, and a thermostat 55. The engine cooling system 50 also includes a coolant circuit 51 through which coolant circulates. The coolant circuit 51 includes coolant circuits 51a, 51b, and 51c.

[0032] The coolant circuit 51a includes a water pump 56, an engine 57, a radiator 54, and a thermostat 55. The coolant circuit 51a is configured to circulate the coolant to the engine 57 via the radiator 54. The coolant circuits 51b and 51c branch off at a branch point 52a downstream of the engine 57 and upstream of the radiator 54 of the coolant circuit 51a, and merge at a junction point 52b downstream of the thermostat 55 of the coolant circuit 51a and upstream of the water pump 56. That is, the coolant circuit 51b and the coolant circuit 51c are provided in parallel.

[0033] The cooling water circuit 51b is provided with an oil cooler 53. The cooling water circuit 51b is configured to merge with the cooling water circuit 51a at a junction 52b without passing through a radiator 54, and to allow the cooling water to flow through the engine 57.

[0034] The coolant circuit 51c is provided with a heater core 59 and an FSV 58. The coolant circuit 51c is configured to merge with the coolant circuit 51a at a junction 52b without passing through the radiator 54, and to allow the coolant to flow through the engine 57.

[0035] The water pump 56 is configured to take in the coolant from the side opposite to the engine 57 in the coolant circuit 51a and discharge the coolant toward the engine 57. In the radiator 54, heat is exchanged between the coolant flowing through the radiator 54 and the running wind. This cools the coolant flowing through the radiator 54. The thermostat 55 is configured to change its opening degree based on the temperature of the coolant. In the oil cooler 53, heat is exchanged between the coolant flowing through the oil cooler 53 and oil used for lubricating sliding parts (not shown) of the engine 57, thereby warming the coolant and cooling the oil.

[0036] In the heater core 59, heat is exchanged between the coolant flowing therethrough and the conditioned air (conditioned air), thereby cooling the coolant and heating the conditioned air. The FSV 58 is a valve member that is opened and closed by electrical suction force. By closing the FSV 58, the flow of coolant in the coolant circuit 51c is blocked. That is, by closing the FSV 58, the flow of coolant to the heater core 59 is blocked.

[0037] <Air conditioning control unit> FIG. 2 is a functional block diagram of the air conditioner ECU 12. The air conditioner 10 is equipped with an air conditioner ECU 12 (ECU: Electronic Control Unit) as a controller. The air conditioner ECU 12 controls various devices included in the air conditioner 10. The air conditioner ECU 12 is physically a computer having a processor and memory. The air conditioner ECU 12 may be configured to include a microcontroller, for example. The memory may include at least one of a semiconductor memory (for example, a RAM, a ROM, a solid state drive, etc.) and a magnetic disk (for example, a hard disk drive, etc.). The air conditioner ECU 12 may be configured only by a computer provided exclusively for the air conditioner 10, or the functions of the air conditioner ECU 12 may be realized by a computer provided integrally for the air conditioner 10 and other devices.

[0038] The air conditioner 10 includes an occupant detection device 29, an outside air temperature sensor 20, an inside air temperature sensor 22, a solar radiation sensor 26, and a vehicle speed sensor 27. The occupant detection device 29 is a device that detects an occupant in the vehicle cabin. The occupant detection device 29 may be, for example, a sensor that detects the opening and closing of a vehicle door (referred to as a door sensor) or a seating sensor. The outside air temperature sensor 20 is a temperature sensor that detects the temperature outside the vehicle. The inside air temperature sensor 22 is a temperature sensor that detects the temperature inside the vehicle. The solar radiation sensor 26 is a sensor that detects the amount of solar radiation irradiated into the vehicle interior. The vehicle speed sensor 27 is a speed sensor that detects the traveling speed of the vehicle. These devices and sensors are electrically connected to the air conditioner ECU 12, and information detected by these devices and sensors is input to the air conditioner ECU 12. In addition, a temperature sensor 45 of an evaporator 42 (see FIG. 1) is electrically connected to the air conditioner ECU 12, and the post-evaporator temperature, which is the detection value of the temperature sensor 45, is input to the air conditioner ECU 12.

[0039] The air conditioner 10 is equipped with an operation panel that is operated by the occupant. The operation panel includes a switch for turning the air conditioning operation on and off, an execution setting button for the front seat concentrated air flow mode (S-Flow) (see FIG. 2), a setting button for the set temperature, etc., and the operation information and setting information thereof are input to the air conditioner ECU 12. The front seat concentrated air flow mode (S-Flow) is a mode that detects which seats in the vehicle cabin an occupant is sitting in, and performs air conditioning only on the seats where an occupant is present, or prioritizes the seats.

[0040] The air conditioner ECU 12 is electrically connected to and controls the air outlet servo motor 75, the blower 62, and the compressor 34. The air outlet servo motor 75 is a servo motor that opens and closes the doors of the air outlets for the conditioned air. These doors include a selective door that selectively opens and closes the air outlets for the driver's seat and the passenger seat. The air conditioner ECU 12 inputs and outputs signals that are not shown in FIG. 2 and includes functional elements that are not shown, but the description thereof will be omitted since they are not closely related to the embodiment.

[0041] The air conditioner ECU 12 has, as functional elements, a target outlet temperature (TAO) setting unit 80, a basic outlet zone setting unit 81, an outlet mode setting unit 82, a basic blower level setting unit 83, a front seat concentrated air flow mode (S-Flow) control unit 84, an outlet zone setting unit 85, a blower level setting unit 86, a compressor control unit 87, a condition determination unit 90, and an FSV power saving control unit 92.

[0042] The air conditioner ECU 12 functions as a setting unit 80 and sets a target outlet temperature (TAO), which is a target temperature of the conditioned air blown into the vehicle cabin, based on the environmental load values ​​of the outside air temperature, the inside air temperature, the amount of solar radiation (solar radiation load), and the set temperature. The air conditioner ECU 12 also functions as setting units 81, 82, and 83 and sets a basic outlet zone, an outlet mode, and a basic blower level based on the target outlet temperature (TAO).

[0043] The blowing zone is an area in the vehicle cabin from which conditioned air is blown out, and includes, for example, the driver's seat, the passenger seat, and all seats (all seats including the rear seats). The blowing mode indicates the outlet from which the conditioned air is blown out, and includes face mode (mode in which conditioned air is blown out toward the occupant's face), bi-level mode (mode in which conditioned air is blown out toward both the occupant's face and feet), foot mode (mode in which conditioned air is blown out toward the occupant's feet), foot / defroster mode, etc. The blower level is the output level of the blower 62.

[0044] In addition, "basic" in the setting units 81, 83 means the basic state in which the front seat concentrated air flow mode (S-Flow) is not being executed (when the front seat concentrated air flow mode execution setting button is off), and the setting units 81, 83 set the blowing zone and blower level when the front seat concentrated air flow mode is not being executed.

[0045] When an occupant turns on the execution setting button for the front seat concentrated airflow mode (S-Flow), the air conditioner ECU 12 functions as the control unit 84. When the occupant detection device 29 detects that an occupant is present only in the driver's seat or the passenger seat, the control unit 84 executes one-seat concentrated airflow in which conditioned air is blown only to the seat in which the occupant is present, or preferentially to that seat. When the occupant detection device 29 detects that an occupant is present only in the front seats (driver's seat and passenger seat), the control unit 84 executes two-seat concentrated airflow in which conditioned air is blown only to the front seat in which the occupant is present, or preferentially to that seat. In other cases, the control unit 84 executes all-seat airflow in which conditioned air is blown to all seats including the rear seats.

[0046] The control unit 84 determines the control (control information) of the blowing zone and the blower level based on the target blowing temperature and the air blowing mode (one-seat concentrated air blowing, two-seat concentrated air blowing, or all-seat concentrated air blowing). The air conditioner ECU 12 functions as setting units 85, 86 and sets the blowing zone and the blower level based on the control information. For example, in the case of one-seat concentrated air blowing, the selected door of the air outlet is controlled so that the conditioned air is blown only to the driver's seat or the passenger seat where an occupant is present, and the blower level is set relatively low. In the case of two-seat concentrated air blowing, the rear seat door 68rs (see FIG. 1) is closed so that the conditioned air is blown only to the front seats where an occupant is present, and the blower level is set lower than in the case of all-seat concentrated air blowing.

[0047] The air conditioner ECU 12 functions as the control unit 87 and sets a post-evaporator temperature target (a post-evaporator temperature target when not in FSV power saving control) based on the target blowing temperature. The post-evaporator temperature target is a target temperature of the post-evaporator temperature (the temperature at the downstream end of the evaporator 42 in the air flow direction). The post-evaporator temperature target may be set taking into consideration the blower level. The control unit 87 controls the compressor 34 so that the post-evaporator temperature approaches the post-evaporator temperature target.

[0048] When the FSV power saving control unit 92 determines that the FSV 58 (see FIG. 1) is in the closed state, it sets the target temperature after the evaporator when the air conditioner 10 operates in the power saving mode (when the FSV power saving control is executed). An FSV open / close signal indicating the open / close state of the FSV 58 is input to the FSV power saving control unit 92. The condition determination unit 90 determines whether a predetermined condition under which the refrigerant passage sound of the refrigeration cycle device 30 is likely to be recognized by the vehicle occupants is satisfied. The detected value (vehicle speed) of the vehicle speed sensor 27 is input to the condition determination unit 90. The FSV power saving control unit 92 and the condition determination unit 90 will be described in detail later.

[0049] <FSV Power Saving Control> During cooling operation, the air conditioner 10 controls to close the FSV 58 to stop the supply of cooling water to the heater core 59 so that the conditioned air cannot be heated by the heater core 59. At this time, as shown in FIG. 1, the air mix door 64 is configured to cover the front of the heater core 59 so that the conditioned air does not pass through the heater core 59. Then, the air conditioner 10 is controlled by the FSV power saving control that relatively reduces the air cooling performance of the evaporator 42. That is, since the conditioned air cannot be heated by the heater core 59, even if the air cooling performance of the evaporator 42 is reduced, it is easy to obtain the conditioned air at the desired cold target blow-out temperature (the target temperature of the conditioned air blown into the vehicle interior). Therefore, the refrigeration cycle device 39 operates in the power saving mode to reduce the power consumption.

[0050] For example, when the target blow-out temperature is 10° C., if the FSV 58 is opened to allow engine coolant to flow through the heater core 59, the surroundings of the heater core 59 will become warm (for example, to about 40° C.), so in order to obtain the target blow-out temperature (10° C.), it is necessary to make the cooling performance of the evaporator 42 relatively high (the post-evaporator temperature target will be lowered, for example, the post-evaporator temperature target will be set to 2° C.). On the other hand, if the FSV 58 is closed to stop the supply of engine coolant to the heater core 59, the surroundings of the heater core 59 will not be warmed (for example, to about 20° C.), so in order to obtain the target blow-out temperature (10° C.), it is possible to make the cooling performance of the evaporator 42 relatively low (the post-evaporator temperature target will be higher, for example, the post-evaporator temperature target will be set to 5° C.). In this way, when the FSV 58 is closed, FSV power saving control can be performed to reduce the air cooling performance of the evaporator 42 (to increase the post-evaporator temperature target). Note that the temperature values ​​given here are examples to facilitate understanding.

[0051] In the FSV power saving control, the post-evaporator temperature target is set relatively high, which reduces the compressor output and reduces the air cooling performance of the evaporator. Therefore, in the FSV power saving control, there is a problem that refrigerant passing noise is likely to occur in the refrigeration cycle device. If the occupants recognize the refrigerant passing noise as noise, the comfort in the vehicle cabin may be impaired. Therefore, in this embodiment, as described later, control that takes the refrigerant passing noise into consideration is added to the FSV power saving control.

[0052] <Mechanism of refrigerant passing noise> Here, the mechanism by which the refrigerant passing sound occurs will be described with reference to Fig. 1. In the refrigeration cycle device 30, the compressor 34 is likely to be controlled to a low compression capacity during execution of FSV power saving control. In other words, the compressor 34 is likely to be driven in a state where the refrigerant discharge capacity is low.

[0053] When the amount of refrigerant circulating in the refrigeration cycle apparatus 30 is small and the cooling load is low, the refrigerant flowing through the evaporator 42 has difficulty obtaining heat required for evaporation from the conditioned air. When the refrigerant flowing through the evaporator 42 does not evaporate completely and some of the refrigerant becomes liquid, the liquid refrigerant tends to accumulate inside the evaporator 42 and inside the low-pressure piping on the suction side of the compressor 34 in the refrigerant piping 32. That is, the proportion of the refrigerant present in the gas phase in the refrigeration cycle apparatus 30 decreases, and the proportion of the refrigerant present in the liquid phase increases.

[0054] In the refrigeration cycle device 30, the compression capacity of the compressor 34 is small and the ratio of gas-phase refrigerant is reduced, so that the refrigerant discharge capacity of the compressor 34, which compresses the gas-phase refrigerant, is very low. For this reason, the amount of refrigerant discharged from the compressor 34 may be smaller than the amount of refrigerant passing through the expansion valve 36. In this state, some of the gas-phase refrigerant passes through the condenser 38 before being condensed in the condenser 38, and flows into the expansion valve 36 in a gas-liquid two-phase state. That is, it becomes difficult to achieve subcooling (subcooling becomes small). The gas-liquid two-phase refrigerant is forced to flow through the expansion valve 36, where the liquid-phase refrigerant should flow, that is, the refrigerant containing bubbles flows, and vibrations occur when the refrigerant passes through. The vibrations generated at this time are transmitted from the expansion valve 36 to the evaporator 42, causing the evaporator 42 to vibrate. The vibration of the evaporator 42 generates radiated sound that is radiated from the evaporator 42 to the inside of the air-conditioning case 61. In this specification, the sound generated due to the passage of the refrigerant is referred to as refrigerant passage sound.

[0055] The refrigerant passing noise generated in the evaporator 42 resonates from inside the air conditioning case 61 to each of the passages 66df, 66fc, 66ft, and 66rs, and when it is transmitted into the vehicle cabin through each of the air outlets, the refrigerant passing noise becomes easily noticeable to the occupants.

[0056] <FSV power saving control that takes into account refrigerant passing noise> Therefore, in this embodiment, FSV power saving control that suppresses the refrigerant passing sound is performed. Specifically, the air conditioner ECU 12 sets a post-evaporator temperature target, which is a target temperature of the post-evaporator temperature, based on the target blowing temperature (see FIG. 4). At this time, the air conditioner ECU 12 functions as an FSV power saving control unit 92, and when the FSV 58 is in a closed state and a predetermined condition is satisfied under which the refrigerant passing sound of the refrigeration cycle device 30 is easily recognized by passengers in the vehicle interior, sets the post-evaporator temperature target lower within a certain range of the target blowing temperature as shown by the solid lines in FIGS. 4(B) and (C) compared with the other cases. As a result, the output of the compressor 34 is increased to suppress the refrigerant passing sound. The compressor control unit 87 (see FIG. 2) controls the compressor 34 so that the post-evaporator temperature target set by the FSV power saving control unit 92 and the actual post-evaporator temperature approach each other. This post-evaporator temperature target may be adjusted by the blower level.

[0057] The predetermined condition is a condition under which background noise, which is a sound other than the refrigerant passing sound generated by the refrigeration cycle device 30, is reduced. For example, the predetermined condition is a state in which the vehicle is stopped. When the vehicle speed detected by the vehicle speed sensor 27 is zero and the vehicle is stopped, it can be estimated that the background noise is low. For example, the predetermined condition is a state in which the one-seat concentrated airflow or the two-seat concentrated airflow of the front seat concentrated airflow mode (S-Flow) is being executed. When the one-seat concentrated airflow or the two-seat concentrated airflow is being executed, the output level (blower level) of the blower is low, so it can be estimated that the background noise is low. Note that when the blower level is low, the post-evaporator temperature target is likely to be set high (the output of the compressor 34 is likely to be low), so that the refrigerant passing sound is likely to be generated. That is, when the one-seat concentrated airflow or the two-seat concentrated airflow is executed, the refrigerant passing sound is likely to be generated, so it is expected that the refrigerant passing sound will be suppressed. A condition determination unit 90 (see FIG. 2) determines whether or not this predetermined condition is satisfied, and sends the determination result to an FSV power saving control unit 92.

[0058] The FSV power saving control unit 92 grasps the open / closed state of the FSV 58 from the FSV open / close signal. Regarding the FSV open / close signal, the air conditioner ECU 12 transmits a request to close the FSV 58 when performing cooling to the engine ECU, and the engine ECU receives this request and decides whether or not to close the FSV 58 while taking into consideration the state of the engine 57, etc., and controls the FSV 58. The engine ECU then transmits an FSV open / close signal (a signal indicating the open / closed state of the FSV 58) to the air conditioner ECU 12.

[0059] A specific embodiment will now be described. Fig. 3 is a flowchart showing processing by the air conditioner 10. In step S10, the air conditioner ECU 12 checks whether the FSV 58 is in a closed state. If the FSV 58 is not in a closed state (is in an open state) (step S10: No), in step S22, the air conditioner ECU 12 sets a post-evaporator temperature target for normal control that is not FSV power saving control. On the other hand, if the FSV 58 is in a closed state (step S10: Yes), the process proceeds to step S12 and subsequent steps, and the air conditioner ECU 12 performs FSV power saving control.

[0060] In step S12, the air conditioner ECU 12 functions as the condition determination unit 90 and checks whether the vehicle is stopped based on the vehicle speed sensor 27. If the vehicle is moving (step S12: No), in step S20, the air conditioner ECU 12 (FSV power saving control unit 92) sets the post-evaporator temperature target based on the normal setting of the FSV power saving control. Figure 4(A) is an image diagram showing the post-evaporator temperature target in the normal setting of the FSV power saving control. As shown in Figure 4(A), the higher the target blown air temperature, the higher the post-evaporator temperature target is.

[0061] On the other hand, if the vehicle is stopped in step S12 (step S12: Yes), the air conditioner ECU 12 proceeds to step S14. In step S14, the air conditioner ECU 12 functions as a condition determination unit 90 and checks whether the single-seat concentrated airflow in the front seat concentrated airflow mode (S-Flow) is being executed, based on information from the airflow zone setting unit 85 (see FIG. 2).

[0062] If step S14 is No (single-seat concentrated airflow is not being performed), that is, if the vehicle is stopped but single-seat concentrated airflow is not being performed, in step S18, the air conditioner ECU 12 (FSV power saving control unit 92) sets the post-evaporator temperature target based on the A2 setting of the FSV power saving control. FIG. 4(B) is a diagram showing the post-evaporator temperature target in the A2 setting of the FSV power saving control. As shown in FIG. 4, in the A2 setting (FIG. 4(B)), the post-evaporator temperature target is set lower in the range (certain range) of the target blowing temperature C3 or higher compared to the normal setting (FIG. 4(A)). When the vehicle is stopped, background noise is low and the refrigerant passing sound is easily noticeable, so the post-evaporator temperature target is lowered by one step in this way to suppress the refrigerant passing sound.

[0063] On the other hand, if step S14 is Yes (if single-seat concentrated airflow is being performed), that is, if the vehicle is stopped and single-seat concentrated airflow is being performed, in step S16, the air conditioner ECU 12 (FSV power saving control unit 92) sets the post-EVA temperature target based on the A1 setting of the FSV power saving control. FIG. 4(C) is a diagram showing the post-EVA temperature target in the A1 setting of the FSV power saving control. As shown in FIG. 4, in the A1 setting (FIG. 4(C)), the post-EVA temperature target is set lower in a certain range (temperature C2 or higher) including a lower temperature (temperature C2 or higher and lower than temperature C3) of the target blowing temperature than in the A2 setting (FIG. 4(B)). When the vehicle is stopped and single-seat concentrated airflow is being performed, the background noise is very low and the refrigerant passing sound is particularly noticeable, so by further lowering the post-EVA temperature target in this manner, the refrigerant passing sound is suppressed.

[0064] According to the embodiment described above, the generation of refrigerant passing noise can be suppressed in the FSV power saving control (air conditioning control when the FSV is closed). Such FSV power saving control increases the air conditioning load a little, increases the heat absorption of the evaporator 42, increases the refrigerant circulation flow rate, and slightly increases the power of the compressor 34. In addition, the temperature and pressure of the refrigerant near the inlet of the condenser 38 increase, and the amount of heat released by the condenser 38 increases a little. Subcooling is easily achieved, and the refrigerant passing noise can be improved. Note that subcooling is the difference between the saturation temperature of the refrigerant in the condenser 38 and the actual temperature of the refrigerant exiting the condenser 38. In other words, the subcooling is the number of degrees the refrigerant has dropped from the saturation temperature. "Easy to achieve subcooling" means that the subcooling is easily increased, and by easily achieving subcooling, the amount of gas-phase refrigerant at the outlet of the condenser 38 is reduced. According to this embodiment, it is possible to achieve both the refrigerant passing noise and the FSV power saving control (practical fuel consumption).

[0065] In the embodiment described above, the post-EVA temperature target is set using two conditions, that is, the vehicle is stopped and one-seat concentrated airflow. However, the post-EVA temperature target may be set using any one of the conditions, that is, the vehicle is stopped, one-seat concentrated airflow, or two-seat concentrated airflow. In other words, when any one of the conditions, that is, the vehicle is stopped, one-seat concentrated airflow, or two-seat concentrated airflow, is satisfied, the post-EVA temperature target may be set lower within a certain range of the target blowing temperature (for example, above a predetermined temperature) compared to the normal setting of the FSV power saving control (FIG. 4(A)). [Explanation of symbols]

[0066] 10 air conditioning device, 12 controller (air conditioning ECU), 20 outside air temperature sensor, 22 inside air temperature sensor, 26 solar radiation sensor, 27 vehicle speed sensor, 29 occupant detection device, 30 refrigeration cycle device, 32 refrigerant piping, 34 compressor, 36 expansion valve, 38 condenser, 40 condenser fan, 42 evaporator, 43 fin, 45 temperature sensor, 50 engine cooling device, 51, 51a, 51b, 51c cooling water circuit, 52a branch point, 52b junction point, 53 oil cooler, 54 radiator, 55 thermostat, 56 water pump, 57 engine, 58 FSV (shutoff valve), 59 heater core, 60 blower unit, 61 air conditioning case, 62 blower, 64 air mix door, 66df defroster passage, 66fc Face aisle, 66ft foot aisle, 66rs rear seat aisle, 68df defroster door, 68fc face door, 68ft foot door, 66rs rear seat door, 70df defroster outlet, 70fc_d face outlet (driver's side), 70fc_p face outlet (passenger's side), 70ft_d foot outlet (driver's side), 70ft_p foot outlet (passenger's side), 70rs rear seat outlet, 71 inside air intake, 72 outside air intake, 73 inside / outside air switching door, 75 outlet servo motor, 80 target outlet temperature setting section, 81 basic outlet zone setting section, 82 outlet mode setting section, 83 basic blower level setting section, 84 front seat concentrated air flow mode control section, 85 outlet zone setting section, 86 blower level setting section, 87 Compressor control unit (Eva post-temperature target setting unit), 90 condition judgment unit, 92 FSV power saving control unit.

Claims

1. A compressor that compresses a refrigerant circulating in the refrigeration cycle device; a condenser for condensing the gas phase refrigerant compressed by the compressor; an expansion valve for expanding the liquid phase refrigerant condensed in the condenser; an evaporator that evaporates the liquid-phase refrigerant by exchanging heat between the liquid-phase refrigerant expanded by the expansion valve and conditioned air provided to the vehicle interior; a sensor for detecting a post-evaporator temperature, which is a temperature at a downstream end of the evaporator in an air flow direction; a refrigerant pipe connecting the compressor, the condenser, the expansion valve, and the evaporator, through which a refrigerant flows; a heater core and an FSV that switches between supplying and not supplying the cooling water to the heater core, the FSV being provided in a cooling water circuit for circulating the cooling water through the engine cooling device; an air conditioning case that accommodates the evaporator and the heater core therein and sends the conditioned air from a blower into a vehicle compartment by passing the conditioned air through the evaporator and selectively passing the conditioned air through the heater core; A controller that controls the air conditioning operation, The controller: A target blowing temperature is set, which is a target temperature of the conditioned air blown into the vehicle compartment; A post-evaporator temperature target, which is a target temperature of the post-evaporator temperature, is set based on the target blowing temperature. Controlling the compressor so that the after-evaporator temperature approaches the after-evaporator temperature target; When the FSV is in a closed state and a predetermined condition is satisfied under which a refrigerant passing sound of the refrigeration cycle device is easily recognized by an occupant in the vehicle interior, the post-evaporator temperature target is set lower within a certain range of the target blow-out temperature than when the predetermined condition is not satisfied. An in-vehicle air conditioning system comprising:

2. The vehicle air conditioner according to claim 1, The predetermined condition includes a stopped state of a vehicle equipped with the air conditioning device. An in-vehicle air conditioning system comprising:

3. 3. The vehicle air conditioner according to claim 2, The predetermined condition is: a state in which the output level of the blower is relatively low due to one-seat concentrated blowing being performed in which the conditioned air is blown only to one seat in the vehicle cabin or preferentially to that seat, The controller, when the vehicle is stopped, When the single-seat concentrated air blowing is in an execution state, the post-evaporator temperature target is set lower within a certain range including a lower temperature of the target blowing temperature, compared to when the single-seat concentrated air blowing is not in an execution state. An in-vehicle air conditioning system comprising:

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