Air-conditioning control device of vehicle

Abstract

To provide an air-conditioning control device of a vehicle which can suppress coolant passing noise in a coolant circulation circuit.SOLUTION: An air-conditioning control device of a vehicle is given in which: when an outside air introduction mode is taken (YES at ST1), when an estimated air conditioning load is a prescribed value or less (YES at ST4), and when outside air temperature is lower than in-cabin temperature (YES at ST6), a suction port mode is switched from the outside air introduction mode to an inside air circulation mode (ST7). Thereby, a situation where the air conditioning load is low is resolved to be capable of suppressing occurrence of coolant passing noise so as to suppress a crewman from feeling discomfort due to the coolant passing noise.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an air conditioning control device for a vehicle. In particular, the present invention relates to an improvement in the switching control of the intake mode.

Background Art

[0002] Conventionally, as disclosed in Patent Document 1, an air conditioner mounted on a vehicle controls the temperature, air volume, etc. of the conditioned air blown into the vehicle interior based on sensor values such as the outside air temperature detected by an outside air temperature sensor and the vehicle interior temperature detected by an inside air temperature sensor, and the set temperature (target temperature) in the vehicle interior.

[0003] In addition, as an intake mode, the air conditioner can switch between an internal air circulation mode in which air in the vehicle interior is taken in (air is circulated between the vehicle interior and the air conditioner) and an outside air introduction mode in which outside air is taken into the vehicle interior (the taken-in outside air is air-conditioned and supplied to the vehicle interior). Regarding the switching control of this intake mode, Patent Document 1 discloses that when it is determined that it is in the eco-run state and the outside air temperature is determined to be equal to or higher than a predetermined value, if it is in the outside air introduction mode, it switches to the internal air circulation mode, while when the outside air temperature is determined to be lower than the predetermined value, it continues the outside air introduction mode without switching to the internal air circulation mode.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when air-conditioning control is performed in the outside air introduction mode in a situation where the outside air temperature is relatively low, the temperature of the outside air (the air taken in), which is the object of air-conditioning, is low, resulting in a low air-conditioning load. Due to this, there was a possibility that the refrigerant passing sound in the refrigerant circulation circuit would increase. As an example of the cause of this refrigerant passing sound, the ratio of the liquid phase of the refrigerant in the refrigerant circulation circuit increases due to the low air-conditioning load (for example, the ratio of the liquid phase increases because the evaporation amount of the refrigerant in the evaporator is small), and the refrigerant flow becomes turbulent, etc. can be cited. In a situation where the refrigerant passing sound increases in this way, it is not preferable because there is a possibility that the occupant will feel discomfort when the refrigerant passing sound is transmitted into the vehicle interior.

[0006] The present invention has been made in view of such a point, and an object thereof is to provide an air-conditioning control device for a vehicle that can suppress the refrigerant passing sound in the refrigerant circulation circuit.

Means for Solving the Problems

[0007] The solution means of the present invention for achieving the above object is premised on an air-conditioning control device that controls an air-conditioning device mounted on a vehicle and whose suction port mode can be switched between an internal air circulation mode and an outside air introduction mode. And this air-conditioning control device is characterized by including a suction port mode switching unit that switches the suction port mode from the outside air introduction mode to the internal air circulation mode on the condition that the estimated air-conditioning load is equal to or less than a predetermined value and the outside air temperature is lower than the vehicle interior temperature when the suction port mode is in the outside air introduction mode.

[0008] Due to this specific matter, in a situation where there is a risk that the refrigerant passing sound will increase due to a low air-conditioning load, by switching the suction port mode from the outside air introduction mode to the internal air circulation mode, the situation of a low air-conditioning load is eliminated, and thereby it becomes possible to suppress the refrigerant passing sound.

Effects of the Invention

[0009] In the present invention, when in the outside air introduction mode, on the condition that the estimated air conditioning load is equal to or less than a predetermined value and the outside air temperature is lower than the vehicle interior temperature, the intake port mode is switched from the outside air introduction mode to the recirculation mode. Thereby, it becomes possible to suppress the refrigerant passage sound by eliminating the situation where the air conditioning load is low, and it is possible to suppress the passengers from feeling discomfort due to the refrigerant passage sound.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described based on the drawings.

[0012] -Configuration of the air conditioning unit- FIG. 1 is a diagram showing a schematic configuration of an air conditioning unit (air conditioner) 6 according to the present embodiment. As shown in this FIG. 1, the air conditioning unit 6 includes an air conditioning duct 7 that forms an air passage for guiding conditioned air into the vehicle interior, a centrifugal blower 61 that generates an air flow in the air conditioning duct 7, a refrigerant circulation circuit 8 for cooling the air flowing in the air conditioning duct 7, and a cooling water circuit 9 for heating the air flowing in the air conditioning duct 7, and the like.

[0013] The most upstream side (windward side) of the air conditioning duct 7 is a part that constitutes an intake port switching box (inside / outside air switching box), and has an inside air intake port 71 for taking in vehicle interior air (inside air) and an outside air intake port 72 for taking in outside air (outside air).

[0014] Furthermore, an inside / outside air switching door 73 is rotatably attached inside the inside air inlet 71 and the outside air inlet 72. This inside / outside air switching door 73 is driven by an actuator 73a (see FIG. 2) such as a servo motor to switch the inlet mode between the inside air circulation mode and the outside air introduction mode.

[0015] Also, the most downstream side (downwind side) of the air conditioning duct 7 is a part that constitutes an outlet switching box, and has a defroster (DEF) opening 74, a face (FACE) opening 75, and a foot (FOOT) opening 76.

[0016] The DEF opening 74 blows conditioned air toward the inner surface of the front windshield FW of the vehicle. Also, the FACE opening 75 blows conditioned air toward the heads and chests of the passengers. Further, the FOOT opening 76 blows conditioned air toward the feet of the passengers.

[0017] And, inside each of the openings 74, 75, 76, outlet switching doors 77, 78 are rotatably attached. These outlet switching doors 77, 78 are respectively driven by actuators 77a, 78a (see FIG. 2) such as servo motors to switch the outlet mode to any one of the face (FACE) mode, the bi-level (B / L) mode, the foot (FOOT) mode, the foot defrost (F / D) mode, and the defroster (DEF) mode.

[0018] The centrifugal blower 61 has a blower 62 rotatably housed in a scroll case integrally formed with the air conditioning duct 7, and a blower motor 63 that rotationally drives the blower 62. The blower motor 63 has its blower air volume (rotation speed of the blower 62) controlled based on a blower terminal voltage applied via a blower drive circuit 63a (see FIG. 2).

[0019] The refrigerant circulation circuit 8 is composed of a compressor 81, a condenser (condenser) 82 into which the refrigerant discharged from the discharge port of the compressor 81 flows, a receiver 83 that separates the condensed and liquefied refrigerant and allows only the liquid refrigerant to flow downstream, an expansion valve 84 that decompresses and expands the liquid refrigerant, an evaporator (evaporator) 85 that evaporates and vaporizes the decompressed and expanded refrigerant, and a refrigerant pipe 86 that connects these in a loop. The evaporator 85 is disposed throughout the entire length of a part of the air passage in the longitudinal direction. The compressor 81 compresses and discharges the inhaled refrigerant and is configured as an electric compressor driven by an electric motor 87. It may also be configured as a mechanical compressor driven by receiving the driving force of the engine EG. When the power associated with the operation of the electric motor 87 is transmitted to the compressor 81, the refrigerant circulates in the refrigerant circulation circuit 8, and air is cooled as the refrigerant evaporates and vaporizes in the evaporator 85.

[0020] The cooling water circuit 9 is a circuit that circulates the cooling water heated in the water jacket of the engine EG by a water pump 93 and has a heater core 91. Engine cooling water flows through the heater core 91, and this engine cooling water is used as a heat source for heating to heat the air. In addition to the heater core 91, the cooling water circuit 9 is provided with a radiator for releasing the heat of the engine cooling water to the atmosphere and a thermostat (both not shown) for switching the circulation path of the cooling water. Since these configurations are well-known, the description here is omitted. The heater core 91 is disposed in a part of the air passage on the downstream side of the evaporator 85 (for example, in the lower half of the passage in a part of the longitudinal direction of the air passage). An air mix door 92 is rotatably attached upstream of the heater core 91. The air mix door 92 is driven by an actuator 92a such as a servo motor (see FIG. 2) and adjusts the temperature of the air blown into the passenger compartment by changing the ratio of the amount of air passing through the heater core 91 to the amount of air bypassing (circulating around) the heater core 91 according to its stop position between the MAX·COOL position where all the air is bypassed from the heater core 91 and the MAX·HOT position where all the air passes through the heater core 91.

[0021] As shown in FIG. 2, the air conditioner ECU (air conditioning control device) 200 is a generally known ECU (Electronic Control Unit) and includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a backup RAM, and the like.

[0022] As shown in FIG. 2, switch signals from various switches on the air conditioner operation panel 400 provided on the front surface of the vehicle interior (instrument panel) and sensor signals from various sensors are input to the air conditioner ECU 200.

[0023] Various switches provided on the air conditioner operation panel 400 include an AUTO switch for automatically controlling the air conditioning unit 6, an A / C switch for forcibly operating the compressor 81, a suction port changeover switch for switching the suction port mode, a temperature setting switch for setting the temperature inside the vehicle to a desired temperature, an air volume changeover switch for setting the air volume of the blower 62 in manual mode, and an air outlet changeover switch for switching the air outlet mode.

[0024] In addition, various sensors connected to the air conditioner ECU 200 include an inside air temperature sensor 110 for detecting the temperature inside the vehicle, an outside air temperature sensor 111 for detecting the outside air temperature, and a solar radiation sensor 112 for detecting the amount of solar radiation irradiated into the vehicle interior.

[0025] The electric motor (electric motor for the compressor 81) 87, the actuators 73a, 77a, 78a, 92a, and the blower drive circuit 63a are connected to the air conditioner ECU 200, and these are controlled in response to the air conditioning requirements inside the vehicle.

[0026] As a feature of this embodiment, the air conditioner ECU 200 includes a suction port mode switching unit 210 as a functional unit realized by a control program. This suction port mode switching unit 210 is a functional unit that controls the drive of the actuator 73a that operates the inside / outside air switching door 73. And, as a function of this suction port mode switching unit 210, when the suction port mode is the outside air introduction mode, the air conditioning load estimated is below a predetermined value, and the outside air temperature is lower than the vehicle interior temperature, the suction port mode is switched from the outside air introduction mode to the recirculated air mode. This will be specifically described below.

[0027] As described above, when air conditioning control is performed in the outside air introduction mode in a situation where the outside air temperature is relatively low, the temperature of the outside air (the air taken in), which is the object of air conditioning, is low, so the air conditioning load is low, and as a result, there was a possibility that the refrigerant passage sound would increase in the refrigerant circulation circuit. In a situation where the refrigerant passage sound increases in this way, it is not preferable because there is a possibility that the occupant will feel discomfort when the refrigerant passage sound is transmitted into the vehicle interior.

[0028] This embodiment has been made in view of such a point, and by the switching control of the suction port mode by the suction port mode switching unit 210, the refrigerant passage sound in the refrigerant circulation circuit 8 is suppressed, and thereby, it is possible to suppress the situation where the occupant feels discomfort due to the refrigerant passage sound.

[0029] In order to exhibit such a function, information on the current suction port mode, information for estimating the air conditioning load, information on the outside air temperature, and information on the vehicle interior temperature are respectively input to the suction port mode switching unit 210, and based on these information, the necessity of switching the suction port mode (when in the outside air introduction mode, the necessity of switching to the recirculated air mode) is determined.

[0030] As information on the current intake port mode, there is a control signal (intake port mode control signal) output from the air conditioner ECU 200 to the actuator 73a. That is, the intake port mode switching unit 210 can determine whether the current intake port mode is the outside air introduction mode by recognizing this control signal. Also, the information on the current intake port mode may be obtained by detecting the rotation position of the inside / outside air switching door 73.

[0031] As information for estimating the air conditioning load, for example, the current vehicle interior temperature and the vehicle interior set temperature (target temperature), etc. are mentioned. That is, the intake port mode switching unit 210 obtains the air conditioning load amount based on, for example, the deviation between the current vehicle interior temperature and the vehicle interior set temperature. For this reason, the lower the temperature of the air taken into the air conditioning duct 7, the lower the value obtained as this air conditioning load amount.

[0032] The information on the outside air temperature is the value of the outside air temperature detected by the outside air temperature sensor 111.

[0033] The information on the vehicle interior temperature is the value of the vehicle interior temperature detected by the inside air temperature sensor 110.

[0034] Based on the above-mentioned various information, when all of the following conditions (1) to (3) are satisfied, the intake port mode switching unit 210 outputs a control signal to the actuator 73a so as to switch the intake port mode from the outside air introduction mode to the inside air circulation mode. (1) The current intake port mode is the outside air introduction mode. (2) The estimated air conditioning load (air conditioning load amount) is equal to or less than a predetermined value (predetermined low load amount). (3) The outside air temperature is lower than the vehicle interior temperature. In this way, in a situation where there is a risk that the refrigerant passage sound increases due to a low air conditioning load, by switching the intake port mode from the outside air introduction mode to the inside air circulation mode, the situation of a low air conditioning load is eliminated, thereby enabling suppression of the refrigerant passage sound.

[0035] - Suction Port Mode Switching Control - Next, the suction port mode switching control according to this embodiment will be described. FIG. 3 is a flowchart showing the procedure of this suction port mode switching control.

[0036] First, in step ST1, it is determined whether the current suction port mode is the outside air introduction mode. If the current suction port mode is the internal air circulation mode and a NO determination is made in step ST1, the process proceeds to step ST2. Assuming that an increase in the refrigerant passage sound due to a low air conditioning load does not occur, the internal air circulation mode is continued and the process returns as it is.

[0037] On the other hand, if the current suction port mode is the outside air introduction mode and a YES determination is made in step ST1, the process proceeds to step ST3 to obtain the air conditioning load amount. As this air conditioning load amount acquisition operation, as described above, it is calculated based on the outside air temperature, etc. (in this case, the outside air temperature corresponds to the temperature of the air taken into the air conditioning duct 7 since it is in the outside air introduction mode).

[0038] After obtaining the air conditioning load amount, the process proceeds to step ST4 to determine whether the air conditioning load amount is equal to or less than a predetermined low load amount (in the present invention, it is determined whether the estimated air conditioning load is equal to or less than a predetermined value). This predetermined low load amount has been determined in advance by experiments and simulations as a load amount at which the above-mentioned refrigerant passage sound may increase.

[0039] If the air conditioning load amount exceeds the predetermined low load amount and a NO determination is made in step ST4, the process proceeds to step ST5. Assuming that an increase in the refrigerant passage sound due to a low air conditioning load does not occur, the outside air introduction mode is continued and the process returns as it is.

[0040] On the other hand, when the air conditioning load is equal to or less than a predetermined low load and a YES determination is made in step ST4, the process proceeds to step ST6 to determine whether the outside air temperature is lower than the vehicle interior temperature. If the outside air temperature is equal to or higher than the vehicle interior temperature and a NO determination is made in step ST6, it is assumed that switching the intake mode from the outside air introduction mode to the recirculation mode cannot eliminate the situation of low air conditioning load, so the process proceeds to step ST5 to continue the outside air introduction mode and returns as it is.

[0041] And when the outside air temperature is lower than the vehicle interior temperature and a YES determination is made in step ST6, the process proceeds to step ST7 to switch the intake mode from the outside air introduction mode to the recirculation mode. That is, the air taken into the air conditioning duct 7 is switched from the cold outside air to the warm vehicle interior air. As a result, the situation of low air conditioning load is eliminated, the evaporation amount of the refrigerant in the evaporator 85 is increased to reduce the proportion of the liquid phase, and the refrigerant passage sound is suppressed.

[0042] - Effects of the Embodiment - As described above, in this embodiment, when in the outside air introduction mode, the air conditioning load (the air conditioning load amount) estimated is equal to or less than a predetermined value (the predetermined low load amount), and the outside air temperature is lower than the vehicle interior temperature. Under these conditions, the intake mode is switched from the outside air introduction mode to the recirculation mode. As a result, it becomes possible to suppress the refrigerant passage sound by eliminating the situation of low air conditioning load, and it is possible to suppress the discomfort felt by the passengers due to the refrigerant passage sound.

[0043] - Other Embodiments - Note that the present invention is not limited to the above embodiment, and all modifications and applications included in the scope of the claims and the scope equivalent thereto are possible.

[0044] For example, in the above embodiment, the air conditioning load amount was obtained based on the outside air temperature and the like. The present invention is not limited to this, and means for acquiring or estimating the ratio of the liquid phase of the refrigerant in the refrigerant circulation circuit 8 may be provided, and the air conditioning load amount may be obtained based on this ratio of the liquid phase (the larger the ratio of the liquid phase, the lower the value of the air conditioning load amount obtained).

Industrial Applicability

[0045] The present invention is applicable to an air conditioner in which the suction port mode of the air conditioner mounted on a vehicle can be switched between an internal air circulation mode and an outside air introduction mode.

Explanation of Signs

[0046] 6…Air conditioning unit (air conditioner) 71…Internal air suction port 72…Outside air suction port 73…Inside / outside air switching door 73a…Actuator 110…Internal air temperature sensor 111…Outside air temperature sensor 200…Air conditioner ECU (air conditioning control device) 210…Suction port mode switching unit

Claims

【Claim 1】 In an air-conditioning control device that controls an air-conditioning device mounted on a vehicle and whose intake port mode can be switched between an internal air circulation mode and an outside air introduction mode, an intake port mode switching unit is provided that switches the intake port mode from the outside air introduction mode to the internal air circulation mode on the condition that the estimated air-conditioning load when the intake port mode is the outside air introduction mode is equal to or less than a predetermined value and the outside air temperature is lower than the vehicle interior temperature. The air-conditioning control device for a vehicle is characterized by this.

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