Air conditioner for vehicle

Abstract

To provide an air conditioner for a vehicle cabin that is able to restrict an increase in carbon dioxide concentration in the vehicle cabin while keeping air in the vehicle cabin clean.SOLUTION: An air conditioner 1 for a vehicle includes: an inside / outside air ratio adjustment unit 7 configured to adjust an inside / outside air ratio that is a ratio of inside air introduced into an air-conditioning duct 3; a blower 5 configured to generate in the air-conditioning duct 3 a flow of air toward inside of a vehicle cabin, to outside air; a filter 4 configured to remove harmful substances contained in air flowing in the air-conditioning duct 3; a harmful substance concentration detection unit 105 configured to detect a concentration of a harmful substance in each of inside and outside of the vehicle cabin; and a control unit 20 configured to control the inside / outside air ratio adjustment unit 7, based on detection information of the harmful substance concentration detection unit 105.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vehicle air conditioner that conditions the interior of a vehicle compartment. [Background technology]

[0002] As an example of a conventional vehicle air conditioner, a vehicle air conditioner described in Patent Document 1 is known. The vehicle air conditioner described in Patent Document 1 has a blower that blows air toward the interior of the vehicle cabin, and a filter that purifies or removes harmful substances contained in the air blown toward the interior of the vehicle cabin. In the vehicle air conditioner described in Patent Document 1, when the concentration of harmful substances in the inside air, which is the air inside the vehicle cabin, is equal to or lower than the concentration of harmful substances in the outside air, which is the air outside the vehicle cabin, that is, when the inside air is cleaner than the outside air, the inside / outside air mode is determined to be the inside air mode in which the inside air is blown into the vehicle cabin. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-132013 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the vehicle air conditioner described in Patent Document 1, when the inside air is cleaner than the outside air, the inside / outside air mode is determined to be the inside air mode, and it is possible to keep the inside of the vehicle interior clean or to purify the inside of the vehicle interior. However, in the inside air mode, outside air is not introduced into the vehicle interior. Therefore, ventilation in the vehicle interior becomes insufficient, and the carbon dioxide concentration in the vehicle interior increases, which may reduce the driver's attention or make the driver feel drowsy.

[0005] An object of the present invention is to provide an air conditioner for a vehicle interior that is capable of suppressing an increase in the carbon dioxide concentration in the vehicle interior while keeping the air in the vehicle interior clean. [Means for solving the problem]

[0006] According to one aspect of the present invention, there is provided an air conditioner for a vehicle, the air conditioner including an air conditioning duct that introduces air introduced from at least one of an inside air inlet that introduces inside air, which is air inside the vehicle cabin, and an outside air inlet that introduces outside air, which is air outside the vehicle cabin, into the vehicle cabin, an inside / outside air ratio adjustment unit that adjusts an inside / outside air ratio that is a ratio of the inside air and the outside air introduced into the air conditioning duct, a blower that generates an air flow toward the vehicle cabin in the air conditioning duct, a cooling / heating unit that cools or heats the air flowing in the air conditioning duct, a filter that removes harmful substances contained in the air flowing in the air conditioning duct, a harmful substance concentration detection unit that detects concentrations of harmful substances inside and outside the vehicle cabin, and a control unit that controls the inside / outside air ratio adjustment unit based on detection information from the harmful substance concentration detection unit. Effect of the Invention

[0007] According to the present invention, it is possible to provide a vehicle interior air conditioner that is capable of suppressing an increase in the carbon dioxide concentration in the vehicle interior while keeping the air in the vehicle interior clean. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic configuration diagram of a vehicle air conditioning device according to an embodiment of the present invention; [Diagram 2] 4 is a flowchart showing an example of vehicle interior environment position control executed by a control unit of the vehicle air conditioner according to the embodiment. [Diagram 3] 4 is a flowchart showing an example of vehicle interior environment position control executed by a control unit of the vehicle air conditioner according to the embodiment. [Figure 4] 4 is a flowchart showing an example of vehicle interior environment position control executed by a control unit of the vehicle air conditioner according to the embodiment. [Diagram 5] 5A to 5C are diagrams illustrating an example of the air volume of a blower and the state of an inside / outside air ratio adjustment unit (amount of inside air circulation, amount of outside air introduced). [Figure 6] 1A and 1B show an example of changes in the state of the blower air volume and inside / outside air ratio adjustment unit, in which FIG. 1A shows the state before the change, and FIG. 1B shows the state after the change. [Figure 7] 5 is a flowchart showing an example of a filter deterioration determination process executed by a control unit of the vehicle air conditioner according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. In this specification, terms such as "first", "second", ..., etc. are used simply to distinguish similar elements, etc., and are not intended to limit the elements, etc. to which they are attached.

[0010] Fig. 1 is a schematic diagram of a vehicle air conditioner according to an embodiment of the present invention. The vehicle air conditioner 1 according to the embodiment is mounted on a vehicle such as an automobile, and is configured to air-condition the vehicle interior by blowing conditioned air into the vehicle interior. As shown in Fig. 1, the vehicle air conditioner 1 according to the embodiment includes an air conditioning duct 3, a blower 5, an inside / outside air ratio adjustment unit 7, a cooling / heating unit 9, an operation setting unit 11, a notification unit 13, and a control unit 20.

[0011] The air conditioning duct 3 has an air passage therein through which air flows in the direction of the arrow X. An inside air inlet 31 and an outside air inlet 32 ​​are formed in a portion of the air conditioning duct 3 on the upstream side of the air flow direction X (hereinafter simply referred to as the "upstream side"). The inside air inlet 31 is an opening for introducing inside air, which is air inside the vehicle cabin, into the air conditioning duct 3, and the outside air inlet 32 ​​is an opening for introducing outside air, which is air outside the vehicle cabin, into the air conditioning duct 3.

[0012] A defroster outlet 33, a face outlet 34, and a foot outlet 35 are formed in a downstream side (hereinafter simply referred to as "downstream side") portion of the air conditioning duct 3 in the air flow direction X. These outlets are openings that open into the vehicle cabin and are openings for blowing air that has flowed through the air conditioning duct 3 into the vehicle cabin. In other words, the air conditioning duct 3 is configured to guide air (inside air) introduced from the inside air inlet 31 and / or air (outside air) introduced from the outside air inlet 32 ​​into the vehicle cabin. The defroster outlet 33 is an opening for blowing air that has flowed through the air conditioning duct 3 toward the windshield of the vehicle, the face outlet 34 is an opening for blowing air that has flowed through the air conditioning duct 3 toward the vicinity of the face of the driver or the passenger in the passenger seat, and the foot outlet 35 is an opening for blowing air that has flowed through the air conditioning duct 3 toward the feet of the driver or the passenger in the passenger seat.

[0013] The defroster outlet 33 is opened and closed by a defroster switching door 41, the face outlet 34 is opened and closed by a face switching door 42, and the foot outlet 35 is opened and closed by a foot switching door 43. In addition, the defroster switching door 41, the face switching door 42, and the foot switching door 43 are controlled by the control unit 20.

[0014] A filter 4 is disposed in the air conditioning duct 3. The filter 4 removes harmful substances (air pollutants such as PM2.5) contained in the air flowing through the air conditioning duct 3. The removal rate of harmful substances by the filter 4, i.e., the filter filtration rate, is 80% or more, and preferably 90% or more. In this embodiment, the filter 4 is disposed immediately downstream of the inside air inlet 31 and the outside air inlet 32 ​​in the air conditioning duct 3, and removes harmful substances contained in the inside air introduced from the inside air inlet 31 and / or harmful substances contained in the outside air introduced from the outside air inlet 32. The filter 4 is replaceable.

[0015] The blower 5 is disposed downstream of the filter 4 in the air conditioning duct 3. The blower 5 is configured to generate, in the air conditioning duct 3, air flows from the inside air inlet 31 and the outside air inlet 32 ​​toward the vehicle compartment. Furthermore, by operating the blower 5, inside air is introduced into the air conditioning duct 3 from the inside air inlet 31 and / or outside air is introduced into the air conditioning duct 3 from the outside air inlet 32. The blower 5 is an electric blower, and start-up, stoppage, and air volume (rotation speed) of the blower 5 are controlled by the control unit 20.

[0016] The inside / outside air ratio adjustment unit 7 is configured to be able to adjust the inside / outside air ratio, which is the ratio between the inside air and the outside air introduced into the air conditioning duct 3. The inside / outside air ratio adjustment unit 7 includes an inside / outside air switching door 71. The inside / outside air switching door 71 is configured to be able to rotate around a first rotation shaft 72 between a first rotation position shown by a solid line in the figure for closing the inside air inlet 31 and a second rotation position shown by a dashed line in the figure for closing the outside air inlet 32. In this embodiment, the inside / outside air ratio adjustment unit 7 is configured to adjust the passing cross-sectional area of ​​the inside air at the inside air inlet 31 and the passing cross-sectional area of ​​the outside air at the outside air inlet 32 ​​by the rotating position of the inside / outside air switching door 71, thereby adjusting the inside / outside air ratio.

[0017] When the inside / outside air switching door 71 is in the first rotation position (solid line), the inside air inlet 31 is closed and only outside air is introduced into the air conditioning duct 3. In other words, the ratio of inside air to outside air introduced into the air conditioning duct 3 (inside / outside air ratio) is 0:100. In this case, the vehicle air conditioner 1 operates in an outside air introduction mode that introduces outside air.

[0018] When the inside / outside air switching door 71 is in the second rotation position (broken line), the outside air inlet 32 ​​is closed and only inside air is introduced into the air conditioning duct 3. In other words, the ratio of inside air to outside air introduced into the air conditioning duct 3 (inside / outside air ratio) is 100:0. In this case, the vehicle air conditioner 1 operates in an inside air circulation mode in which the inside air is circulated.

[0019] When the inside / outside air switching door 71 is in an intermediate rotation position between the first rotation position and the second rotation position, the ratio of inside air to outside air introduced into the air conditioning duct 3 (inside / outside air ratio) is determined according to the rotation position of the inside / outside air switching door 71.

[0020] The inside / outside air ratio adjusting unit 7, specifically, the rotation position of the inside / outside air switching door 71 of the inside / outside air ratio adjusting unit 7, can be controlled by the control unit 20. The inside / outside air ratio can also be considered as the ratio between the amount of inside air circulating and the amount of outside air introduced in the vehicle air conditioner 1.

[0021] The cooling / heating unit 9 is configured to cool or heat the air flowing through the air conditioning duct 3. The cooling / heating unit 9 includes an evaporator 91 and a heater core 93.

[0022] The evaporator 91 is disposed downstream of the blower 5 in the air conditioning duct 3. The evaporator 91, together with a compressor, a condenser, an expansion valve, and the like (not shown), is disposed in a refrigerant circulation path through which a refrigerant circulates, thereby constituting a refrigerant circuit (refrigeration cycle). The evaporator 91 is configured to cool the air flowing in the air conditioning duct 3 by exchanging heat between the refrigerant flowing inside the evaporator 91 and the air flowing in the air conditioning duct 3. In other words, the evaporator 91 functions as a cooler that cools the air flowing in the air conditioning duct 3.

[0023] The heater core 93 is disposed downstream of the evaporator 91 in the air conditioning duct 3. Although not particularly limited, in this embodiment, the heater core 93 is disposed in a heat medium circulation path in which a heat medium such as water circulates together with a heat medium heating device not shown. The heater core 93 is configured to heat the air flowing in the air conditioning duct 3 by exchanging heat between the heat medium flowing inside (i.e., the heat medium heated by the heat medium heating device) and the air flowing in the air conditioning duct 3. In other words, the heater core 93 functions as a heater that heats the air flowing in the air conditioning duct 3.

[0024] Here, an air mix door 95 is disposed between the evaporator 91 and the heater core 93. The air mix door 95 is configured to adjust the ratio between the flow rate (air volume) of air passing through the heater core 93 and the flow rate (air volume) of air bypassing the heater core 93. Specifically, in this embodiment, the air mix door 95 is configured to be rotatable around a second rotating shaft 96, and rotates between a third rotation position indicated by a solid line in the figure and a fourth rotation position indicated by a dashed line in the figure.

[0025] When the air mix door 95 is in the third rotation position (solid line), the air that has passed through the evaporator 91 passes through the heater core 93. Therefore, the air heated by the heater core 93 flows to the defroster outlet 33, the face outlet 34, and the foot outlet 35. Therefore, the temperature of the conditioned air blown into the vehicle cabin is the highest. When the air mix door 95 is in the fourth rotation position (broken line), the air that has passed through the evaporator 91 flows to the defroster outlet 33, the face outlet 34, and the foot outlet 35 without passing through the heater core 93. Therefore, the temperature of the conditioned air blown into the vehicle cabin is the lowest. The rotation position of the air mix door 95 is appropriately adjusted between the third rotation position and the fourth rotation position, thereby adjusting the temperature of the conditioned air blown into the vehicle cabin. The rotation position of the air mix door 95 is controlled by the control unit 20.

[0026] The operation setting unit 11 is provided in the vehicle cabin. The operation setting unit 11 is operated by an occupant (mainly the driver) in the vehicle cabin to turn the vehicle air conditioner 1 on / off and to perform various settings. When the vehicle air conditioner 1 is turned on, the vehicle cabin temperature (target temperature), the air volume of the conditioned air (air volume of the blower 5), the air outlet of the conditioned air, and the like are set by the operation setting unit 11, and these setting information are output from the operation setting unit 11 to the control unit 20.

[0027] The notification unit 13 is provided in the vehicle cabin, similar to the operation setting unit 11. Based on a command from the control unit 20, the notification unit 13 issues a predetermined notification to the occupants in the vehicle cabin by display and / or sound.

[0028] Setting information is input to the control unit 20 from the operation setting unit 11. The vehicle air conditioner 1 also includes various detection units, and detection information from the various detection units is input to the control unit 20. The various detection units include an interior air temperature detection unit 101 that detects the temperature inside the vehicle cabin, an exterior air temperature detection unit 102 that detects the temperature outside the vehicle cabin, an occupant number detection unit 103 that detects the number of occupants in the vehicle cabin, a carbon dioxide (CO2) concentration detection unit 104 that detects the concentration of carbon dioxide (CO2) inside the vehicle cabin, and a harmful substance concentration detection unit 105 that detects the concentrations of harmful substances inside and outside the vehicle cabin.

[0029] Each of the above detection units may be configured with an appropriate sensor. That is, the inside air temperature detection unit 101 may be a first ambient temperature sensor provided inside the vehicle cabin. The outside air temperature detection unit 102 may be a second ambient temperature sensor provided outside the vehicle cabin. The number of occupants detection unit 103 may be configured with a plurality of seating sensors each provided at each seat inside the vehicle cabin. The CO2 concentration detection unit 104 may be a CO2 concentration sensor provided inside the vehicle cabin (particularly near the driver's seat). The harmful substance concentration detection unit 105 may be configured with a first harmful substance concentration sensor provided inside the vehicle cabin and a second harmful substance concentration sensor provided outside the vehicle cabin.

[0030] Here, the occupant number detection unit 103 may be composed of an imaging unit that images the interior of the vehicle cabin, and a processing unit that counts the number of occupants from the captured image by image processing. In this embodiment, the hazardous substance concentration detection unit 105 is composed of one hazardous substance concentration sensor that functions as the first hazardous substance concentration sensor and the second hazardous substance concentration sensor, and this one hazardous substance concentration sensor has a first intake and exhaust pipe 105a that draws in outside air, passes it through the sensor unit, and then discharges it, as shown in Fig. 1, and a second intake and exhaust pipe 105b that draws in inside air, passes it through the sensor unit, and then discharges it.

[0031] The control unit 20 executes air conditioning control mainly based on the setting information input from the operation setting unit 11, the detection information from the inside air temperature detection unit 101, and the detection information from the outside air temperature detection unit 102. As a result, conditioned air according to the settings in the operation setting unit 11 is blown into the vehicle cabin.

[0032] Furthermore, in this embodiment, the control unit 20 is configured to perform vehicle interior environment maintenance control that suppresses an increase in the CO2 concentration in the vehicle interior while keeping the air in the vehicle interior clean, thereby maintaining a good environment in the vehicle interior. Specifically, the control unit 20 controls the blower 5 and the inside / outside air ratio adjustment unit 7 so that the concentration of harmful substances in the vehicle interior is equal to or lower than a first threshold value, and the concentration of CO2 in the vehicle interior is equal to or lower than a second threshold value. The first threshold value may be set according to the type of harmful substance. Although not particularly limited, when the harmful substance is fine particulate matter such as PM2.5, the first threshold value is, for example, 15.4 [μg / m 3 The second threshold may be set to, for example, 1100 ppm.

[0033] Furthermore, in this embodiment, the control unit 20 judges the deterioration of the filter 4, and if it determines that the filter 4 is deteriorated, it is configured to notify the occupants in the vehicle cabin via the alarm unit 13 to encourage them to clean or replace the filter 4.

[0034] The "vehicle interior environment maintenance control" and "processing for determining deterioration of the filter 4" executed by the control unit 20 will be described below.

[0035] [In-vehicle environment maintenance control] 2 to 4 are flowcharts showing an example of the vehicle interior environment maintenance control.

[0036] In step S1, the control unit 20 determines the number of occupants in the vehicle cabin based on the detection information from the occupant number detection unit 103.

[0037] In step S2, the control unit 20 calculates the required ventilation amount (=amount of outside air introduced) for the vehicle compartment based on the number of occupants in the vehicle compartment grasped in step S1, using the following formula. Required ventilation volume [m 3 / h] = ventilation volume per person [m 3 / h] x number of crew members Here, the ventilation volume per person is set based on the CO2 production of an adult.

[0038] In step S3, the control unit 20 checks the current air volume of the blower 5. The control unit 20 can check the current air volume of the blower 5 by calculating the air volume of the blower 5 based on the current rotation speed of the blower 5.

[0039] In step S4, the control unit 20 sets an inside / outside air ratio (i.e., the ratio of inside air to outside air introduced into the air conditioning duct 3) based on the required ventilation volume calculated in step S2 and the current air volume of the blower 5 confirmed in step S3. Specifically, the control unit 20 sets an inside / outside air ratio that provides an amount of outside air introduced equivalent to the required ventilation volume of the vehicle compartment according to the number of occupants under the current air volume of the blower 5. As a result, the inside / outside air ratio adjustment unit 7 (the rotation position of the inside / outside air switching door 71) is controlled to achieve the set inside / outside air ratio, and outside air is introduced into the air conditioning duct 3 in an amount equivalent to the required ventilation volume calculated in step S2.

[0040] For example, if the required ventilation volume calculated in step S2 is 100 [m 3 / h], and the air volume of the blower confirmed in step S3 is 200 [m 3 / h], the control unit 20 sets the inside / outside air ratio to 50:50 and controls the inside / outside air ratio adjustment unit 7 (the rotation position of the inside / outside air switching door 71) in order to introduce an amount of outside air equivalent to the required ventilation volume into the air conditioning duct 3. As a result, as shown in FIG. 3 / h] and 100[m 3 / h] of outside air is introduced into the air conditioning duct 3.

[0041] Returning to FIG. 2, in step S5, the control unit 20 determines whether the concentration of harmful substances in the vehicle cabin, i.e., the concentration of harmful substances in the inside air (hereinafter referred to as "vehicle cabin harmful substance concentration"), is equal to or higher than a first threshold value based on the detection information from the harmful substance concentration detection unit 105. As described above, when the harmful substances are fine particulate matter such as PM2.5, the first threshold value is, for example, 15.4 [μg / m 3If the concentration of harmful substances in the vehicle interior is less than the first threshold (step S5; NO), the control unit 20 proceeds to step S6. On the other hand, if the concentration of harmful substances in the vehicle interior is equal to or greater than the first threshold (step S5; YES), the control unit 20 proceeds to the process of step S7.

[0042] In step S6, the control unit 20 executes the normal mode (see FIG. 4). Then, when the control unit 20 executes the normal mode, the process proceeds to step S10.

[0043] In step S7, the control unit 20 determines whether the concentration of harmful substances outside the vehicle cabin, i.e., the concentration of harmful substances in the outside air (hereinafter referred to as "external harmful substance concentration"), is equal to or greater than a first threshold value based on the detection information from the harmful substance concentration detection unit 105. If the external harmful substance concentration is less than the first threshold value (step S7; NO), the control unit 20 proceeds to step S8. On the other hand, if the external harmful substance concentration is equal to or greater than the first threshold value (step S7; YES), the control unit 20 proceeds to processing in step S9.

[0044] In step S8, the control unit 20 increases the ratio of outside air. Here, the ratio of outside air is maximized. Specifically, the control unit 20 sets the inside / outside air ratio to 0:100, and sets the inside / outside air switching door 71 of the inside / outside air ratio adjustment unit 7 to the first rotation position. This allows the maximum amount of outside air to be introduced under the current blowing volume of the blower 5. Then, when the control unit 20 has increased the ratio of outside air (maximized the ratio of outside air), the process returns to step S5.

[0045] When the concentration of harmful substances in the vehicle interior is equal to or higher than the first threshold value and the concentration of harmful substances outside the vehicle interior is lower than the first threshold value, for example, there is a possibility that an occupant in the vehicle interior has smoked a cigarette. Therefore, the control unit 20 maximizes the ratio of outside air (amount of outside air introduced) in order to quickly eliminate the state in which the concentration of harmful substances in the vehicle interior is equal to or higher than the first threshold value.

[0046] In step S9, the control unit 20 executes an air volume increase mode for increasing the air volume of the blower 5 (see FIG. 3). Then, after executing the air volume increase mode, the control unit 20 proceeds to the process of step S10.

[0047] In step S10, the control unit 20 determines whether the concentration of CO2 in the vehicle cabin, i.e., the CO2 concentration in the inside air (hereinafter referred to as "vehicle cabin CO2 concentration"), is equal to or higher than the second threshold value based on the detection information of the CO2 concentration detection unit 104. As described above, the second threshold value is set to, for example, 1100 ppm. If the vehicle cabin CO2 concentration is equal to or higher than the second threshold value (step S10; YES), the control unit 20 proceeds to step S11. On the other hand, if the vehicle cabin CO2 concentration is lower than the second threshold value (step S10; NO), the control unit 20 proceeds to the process of step S12.

[0048] In step S11, the control unit 20 increases the ratio of outside air. In other words, the control unit 20 changes the inside / outside air ratio so as to increase the ratio of outside air (so as to decrease the ratio of inside air). Then, when the ratio of outside air is increased, the control unit 20 returns to the processing of step S5.

[0049] For example, if the currently set inside / outside air ratio is 50:50, the control unit 20 increases the outside air ratio by α to change the inside / outside air ratio to 50-α:50+α. The control unit 20 also controls the inside / outside air ratio adjustment unit 7 (the rotation position of the inside / outside air switching door 71) so as to achieve the changed inside / outside air ratio. This increases the amount of outside air introduced, thereby decreasing the CO2 concentration in the vehicle cabin. Here, the increase in the outside air ratio (change in the inside / outside air ratio) α may be a constant value, or may be set to a larger value as the difference between the CO2 concentration in the vehicle cabin and the second threshold value increases.

[0050] In step S12, the control unit 20 reduces the ratio of outside air. In other words, the control unit 20 changes the inside / outside air ratio so as to reduce the ratio of outside air (so as to increase the ratio of inside air). For example, if the currently set inside / outside air ratio is 50:50, the control unit 20 reduces the ratio of outside air by β, changes the inside / outside air ratio to 50+β:50-β, and controls the inside / outside air ratio adjustment unit 7 (the rotation position of the inside / outside air switching door 71) to achieve the changed inside / outside air ratio. Then, after reducing the ratio of outside air, the control unit 20 returns to the processing of step S5.

[0051] FIG. 3 is a flowchart showing an example of the process of the air volume increase mode executed in step S9 of FIG.

[0052] In step S91, the control unit 20 determines whether the airflow increase mode is being executed, i.e., whether the airflow of the blower 5 is being increased. If the airflow increase mode is being executed, the control unit 20 proceeds to step S92 and continues the airflow increase mode. On the other hand, if the airflow increase mode is not being executed, the control unit 20 proceeds to the process of step S93.

[0053] In step S93, the control unit 20 issues a notification via the notification unit 13 to the occupants in the vehicle compartment urging them not to open the vehicle compartment windows.

[0054] In step S94, the control unit 20 stores the air volume (rotation speed) of the blower 5.

[0055] In step S95, the control unit 20 increases the rotation speed of the blower 5 to increase the air volume of the blower 5. Here, the increase in the air volume (rotation speed) of the blower 5 may be a constant value, or may be set to a value that increases as the difference between the concentration of harmful substances outside the vehicle cabin and the first threshold value increases. As an example, when the concentration of harmful substances outside the vehicle cabin is 10 times or more the first threshold value, the control unit 20 can increase the air volume of the blower 5 to more than twice the current air volume.

[0056] In step S96, the control unit 20 resets the inside / outside air ratio based on the air volume of the blower 5 increased in step S95 and the required ventilation volume calculated in step S2 of Fig. 2. Specifically, the control unit 20 resets the inside / outside air ratio such that the amount of outside air introduced corresponds to the required ventilation volume calculated in step S2 of Fig. 2 under the increased air volume of the blower 5. As a result, the inside / outside air ratio adjustment unit 7 (the rotation position of the inside / outside air switching door 71) is controlled to achieve the reset inside / outside air ratio, the amount of inside air circulation increases, and outside air is introduced into the air conditioning duct 3 in an amount corresponding to the required ventilation volume calculated in step S2.

[0057] For example, if the required ventilation volume calculated in step S2 of Figure 2 is 100 [m 3 / h], and the current air volume of the blower 5 in Figure 2 is 200 [m 3 / h], and the current inside / outside air ratio is 50:50, and the concentration of harmful substances outside the vehicle is 200 [μg / m 3 ], the control unit 20 first increases the air volume of the blower 5 to 400 [m 3 Next, the control unit 20 changes the inside / outside air ratio to the required ventilation volume (100 [m 3 1. The controller 20 resets the indoor / outdoor air ratio to 75:25, which is an indoor / outdoor air ratio that provides an outdoor air introduction amount equivalent to the indoor / outdoor air ratio ([1 / h]), and controls the indoor / outdoor air ratio adjustment unit 7 (the rotational position of the indoor / outdoor air switching door 71) based on the reset indoor / outdoor air ratio. In other words, the controller 20 controls the blower 5 to increase the air volume, and controls the indoor / outdoor air ratio adjustment unit 7 to decrease the ratio of outdoor air in accordance with the increased air volume of the blower 5 (conversely, to increase the ratio of indoor air). Furthermore, in this embodiment, the controller 20 controls the indoor / outdoor air ratio adjustment unit 7 so that the outdoor air introduction amount is maintained before and after the increase in the air volume of the blower 5.

[0058] For the sake of convenience, the filter filtration rate is set to 80% or more, and the concentration of harmful substances in the vehicle interior is set to 0 [μg / m 3 By increasing the air volume of the blower 5 and resetting the inside / outside air ratio as described above, the amount of outside air introduced (100 [m 3 / h]), the concentration of harmful substances in the air that passes through the filter, i.e., the air blown into the vehicle cabin, is 20 [μg / m 3 ] to 10[μg / m 3 ]. In addition, the amount of internal air circulation, that is, the amount of internal air that passes through the filter 4 per unit time, is increased. Here, the amount of internal air circulation is reduced by three times (100 [m 3 / h]→300[m 3 / h]. Therefore, harmful substances are effectively removed from the air inside the vehicle cabin by the filter 4. Furthermore, because the ratio of outside air is decreasing (the ratio of inside air is increasing), the increase in the load for heating and / or cooling the air flowing through the air conditioning duct 3 is also suppressed.

[0059] In other words, by increasing the air volume of the blower 5 and resetting the inside / outside air ratio as described above, the control unit 20 introduces an amount of outside air capable of suppressing an increase in the CO2 concentration inside the vehicle cabin, while increasing the ratio of inside air and the amount of inside air circulation, thereby preventing the concentration of harmful substances inside the vehicle cabin from exceeding the first threshold value, and the CO2 concentration inside the vehicle cabin from exceeding the second threshold value, without significantly changing the cooling and heating capacity of the vehicle air conditioning unit 1.

[0060] FIG. 4 is a flowchart showing an example of the normal mode process executed in step S6 of FIG.

[0061] In step S61, the control unit 20 determines whether or not the normal mode is being executed. If the normal mode is being executed, the control unit 20 proceeds to step S62 and continues the normal mode. On the other hand, if the normal mode is not being executed (in other words, if the air volume increase mode is being executed), the control unit 20 proceeds to the process of step S63.

[0062] In step S63, the control unit 20 cancels the above-mentioned notification (see step S93 in FIG. 3) urging the driver not to open the vehicle interior window.

[0063] In step S64, the control unit 20 returns the air volume (rotation speed) of the blower 5 to the air volume (rotation speed) stored in step S94 of FIG.

[0064] In step S65, the control unit 20 resets the inside / outside air ratio based on the air volume of the blower 5 returned in step S63 and the required ventilation volume calculated in step S2 of FIG.

[0065] [Filter 4 deterioration judgment process] 7 is a flowchart showing an example of a deterioration determination process for the filter 4. This flowchart is repeatedly executed at a predetermined cycle while the vehicle air conditioner 1 is in operation.

[0066] In step S31, the control unit 20 grasps the hazardous substance concentration inside the vehicle compartment and the hazardous substance concentration outside the vehicle compartment based on the detection information from the hazardous substance concentration detection unit 105.

[0067] In step S32, the control unit 20 judges whether or not the difference between the concentration of harmful substances outside the vehicle compartment and the concentration of harmful substances inside the vehicle compartment (hereinafter simply referred to as the "difference between the two concentrations") is equal to or greater than a predetermined value. Although not particularly limited, the predetermined value is 10 [μg / m 3 ]. If the difference between the two concentrations is equal to or greater than the predetermined value, the control unit 20 proceeds to the process of step S33. On the other hand, if the difference between the two concentrations is less than the predetermined value, the control unit 20 ends this flow. If the difference between the two concentrations is less than the predetermined value, it is possible that a window in the vehicle compartment is open, that a door is open, or that the door has just been opened, which is not suitable for performing the deterioration determination of the filter 4 in this embodiment. Therefore, if the difference between the two concentrations is less than the predetermined value, the control unit 20 ends this flow.

[0068] In step S33, the control unit 20 confirms the current air volume of the blower 5 and the current inside / outside air ratio.

[0069] In step S34, the control unit 20 calculates the amount of inside air (inside air circulation amount) and the amount of outside air (outside air introduction amount) introduced into the air conditioning duct 3 based on the current air volume of the blower 5 and the current inside / outside air ratio.

[0070] In step S35, the control unit 20 calculates the amount of harmful substances contained in the inside air (hereinafter referred to as the "amount of harmful substances in the inside air") based on the amount of circulating inside air and the concentration of harmful substances in the vehicle cabin, and calculates the amount of harmful substances contained in the outside air (hereinafter referred to as the "amount of harmful substances in the outside air") based on the amount of outside air introduced and the concentration of harmful substances outside the vehicle cabin.

[0071] In step S36, the control unit 20 calculates the concentration of harmful substances in the air introduced into the air conditioning duct 3 before it passes through the filter, using the following formula. Concentration of harmful substances before passing through the filter = (amount of harmful substances in inside air + amount of harmful substances in outside air) / (amount of recirculated inside air + amount of introduced outside air)

[0072] In step S37, the control unit 20 regards the harmful substance concentration in the vehicle cabin as the harmful substance concentration after passing through the filter, and calculates the filter efficiency for harmful substances based on the harmful substance concentration before passing through the filter and the harmful substance concentration after passing through the filter calculated in step S36.

[0073] In step S38, the control unit 20 determines whether the filter efficiency calculated in step S37 is less than the judgment threshold. Although not particularly limited, the judgment threshold may be, for example, 60%, preferably 70%. If the calculated filter efficiency is equal to or greater than the judgment threshold, the control unit 20 ends this flow. On the other hand, if the calculated filter efficiency is less than the judgment threshold, the control unit 20 proceeds to the process of step S39.

[0074] In step S39, the control unit 20 determines that the filter 4 has deteriorated.

[0075] In step S40, the control unit 20 issues a notification to the passengers (particularly the driver) in the vehicle compartment via the notification unit 13 to urge them to replace or clean the filter 4.

[0076] As described above, in the vehicle air conditioner 1 according to the embodiment, the control unit 20 is configured to control the inside / outside air ratio adjustment unit 7 based on the detection information of the harmful substance concentration detection unit 105. Therefore, the amount of inside air circulation and the amount of outside air introduction can be appropriately adjusted according to the concentration of harmful substances outside the vehicle cabin and the concentration of harmful substances inside the vehicle cabin while maintaining the air volume of the blower 5. Therefore, according to the vehicle air conditioner 1 according to the embodiment, it is possible to keep the air in the vehicle cabin clean and suppress an increase in the carbon dioxide concentration in the vehicle cabin without significantly changing the cooling / heating capacity of the vehicle air conditioner 1.

[0077] Specifically, in this embodiment, when the concentration of harmful substances inside the vehicle cabin is equal to or higher than the first threshold value and the concentration of harmful substances outside the vehicle cabin is less than the first threshold value, the control unit 20 controls the inside / outside air ratio adjustment unit 7 to increase the ratio of outside air. More specifically, the control unit 20 controls the inside / outside air ratio adjustment unit 7 to maximize the ratio of outside air. Therefore, it is possible to quickly reduce the concentration of harmful substances inside the vehicle cabin by using outside air with a low concentration of harmful substances, and also to suppress an increase in the carbon dioxide concentration inside the vehicle cabin.

[0078] Furthermore, the control unit 20 controls the blower 5 and the inside / outside air ratio adjustment unit 7 based on the detection information of the harmful substance concentration detection unit 105 and the detection information of the CO2 concentration detection unit 104. Therefore, the amount of inside air circulation and the amount of outside air introduction can be appropriately adjusted according to the concentration of harmful substances outside the vehicle cabin, the concentration of harmful substances inside the vehicle cabin, and the CO2 concentration inside the vehicle cabin.

[0079] Specifically, in this embodiment, when the concentration of harmful substances in the vehicle cabin is equal to or higher than the first threshold and the concentration of harmful substances outside the vehicle cabin is equal to or higher than the first threshold, the control unit 20 controls the blower 5 to increase the air volume, and controls the inside / outside air ratio adjustment unit 7 to decrease the ratio of outside air according to the increased air volume of the blower 5. More specifically, the control unit 20 controls the blower 5 to increase the air volume, and controls the inside / outside air ratio adjustment unit 7 to maintain the amount of outside air introduced before and after the increase in the air volume of the blower 5. Then, when the concentration of carbon dioxide in the vehicle cabin is less than the second threshold, the control unit 20 controls the inside / outside air ratio adjustment unit to further decrease the ratio of outside air. Also, when the concentration of carbon dioxide in the vehicle cabin is equal to or higher than the second threshold, the control unit 20 controls the inside / outside air ratio adjustment unit to increase the ratio of outside air. This makes it possible to effectively remove harmful substances contained in the inside air by the filter 4 by increasing the amount of inside air circulation while minimizing the amount of outside air containing a high concentration of harmful substances, and to suppress an increase in the heating and / or cooling load by increasing the ratio of inside air. Therefore, according to the vehicle air conditioner 1 according to the embodiment, it is possible to keep the air in the vehicle cabin clean and suppress an increase in the carbon dioxide concentration in the vehicle cabin without significantly changing the cooling / heating capacity of the vehicle air conditioner 1.

[0080] In this embodiment, the hazardous substance concentration detection unit 105 that detects the concentrations of hazardous substances inside and outside the vehicle cabin is composed of one hazardous substance concentration sensor, so that the hazardous substance concentration detection unit 105 can be disposed at a desired position without increasing the size of the vehicle air conditioner 1.

[0081] The control unit 20 judges whether the filter 4 has deteriorated based on the concentration of harmful substances in the vehicle cabin, the concentration of harmful substances outside the vehicle cabin, the air volume of the blower 5, and the inside / outside air ratio. Specifically, in this embodiment, the control unit 20 calculates the concentration of harmful substances in the air before passing through the filter 4 based on the concentration of harmful substances in the vehicle cabin, the concentration of harmful substances outside the vehicle cabin, the air volume of the blower 5, and the inside / outside air ratio, calculates the filter efficiency for harmful substances based on the calculated concentration of harmful substances in the air before passing through the filter 4 and the concentration of harmful substances in the vehicle cabin, and judges that the filter 4 has deteriorated when the calculated filter efficiency is less than a judgment threshold. Therefore, according to the vehicle air conditioner 1 according to the embodiment, it is possible to judge the deterioration of the filter 4 not only during internal air circulation but also during introduction of outside air.

[0082] Moreover, the vehicle air conditioner 1 according to the embodiment includes a notification unit 13 that, when the control unit 20 determines that the filter 4 is deteriorated, prompts an occupant in the vehicle cabin to clean or replace the filter 4. This can prevent the filter 4 in a deteriorated state from being continuously used.

[0083] Although the embodiment of the present invention has been described above, the present invention is not limited to the above-mentioned embodiment, and it goes without saying that further modifications are possible based on the technical concept of the present invention.

[0084] For example, the control unit 20 may be configured to control the inside / outside air ratio adjustment unit 7 so that when the concentration of harmful substances outside the vehicle cabin is less than a first threshold, outside air equivalent to the required ventilation volume for the vehicle cabin based on the number of occupants is introduced into the air conditioning duct 3, and when the concentration of harmful substances outside the vehicle cabin is equal to or greater than the first threshold, control the blower 5 to increase the airflow compared to when the concentration of harmful substances outside the vehicle cabin is less than the first threshold, and control the inside / outside air ratio adjustment unit 7 so that outside air equivalent to the required ventilation volume is introduced into the air conditioning duct 3 at the increased airflow of the blower 5.

[0085] In addition, the control unit 20 may calculate the concentration of harmful substances in the air before it passes through the filter 4 as described above, and determine that the filter 4 is deteriorated if the time-integrated value obtained by multiplying the calculated concentration of harmful substances in the air before it passes through the filter 4 by the air volume of the blower 5 exceeds a judgment threshold for the integrated value. [Explanation of symbols]

[0086] 1...vehicle air conditioning device, 3...air conditioning duct, 4...filter, 5...blower, 7...inside / outside air ratio adjustment section, 9...cooling / heating section, 11...operation setting section, 13...alarm section, 20...control section, 31...inside air inlet, 32...outside air inlet, 71...inside / outside air switching door, 91...evaporator (cooler), 93...heater core (heater), 95...air mix door, 101...inside air temperature detection section, 102...outside air temperature detection section, 103...occupant number detection section, 104...carbon dioxide concentration detection section, 105...harmful substance concentration detection section

Claims

1. an air conditioning duct that introduces air introduced from at least one of an inside air inlet that introduces inside air, which is air inside the vehicle cabin, and an outside air inlet that introduces outside air, which is air outside the vehicle cabin, into the vehicle cabin; an indoor / outdoor air ratio adjustment unit that adjusts an indoor / outdoor air ratio, which is a ratio between the indoor air and the outdoor air introduced into the air conditioning duct; a blower that generates an air flow toward the vehicle interior in the air conditioning duct; A cooling / heating unit that cools or heats air flowing through the air conditioning duct; a filter for removing harmful substances contained in the air flowing through the air conditioning duct; a hazardous substance concentration detection unit that detects concentrations of hazardous substances inside and outside the vehicle compartment; a control unit that controls the inside / outside air ratio adjustment unit based on detection information from the hazardous substance concentration detection unit; 13. A vehicle air conditioning system comprising:

2. 2. The vehicle air conditioning system according to claim 1, wherein the control unit controls the inside / outside air ratio adjustment unit to increase the ratio of the outside air when a concentration of harmful substances inside the vehicle cabin is equal to or greater than a first threshold value and a concentration of harmful substances outside the vehicle cabin is less than the first threshold value.

3. The vehicle further includes a carbon dioxide concentration detection unit that detects a concentration of carbon dioxide in the vehicle cabin. The vehicle air conditioner according to claim 1 , wherein the control unit controls the blower and the inside / outside air ratio adjustment unit based on detection information from the hazardous substance concentration detection unit and detection information from the carbon dioxide concentration detection unit.

4. 4. The vehicle air conditioning system according to claim 3, wherein the control unit controls the blower to increase an air volume when a concentration of harmful substances inside the vehicle cabin is equal to or higher than the first threshold and a concentration of harmful substances outside the vehicle cabin is equal to or higher than the first threshold, and controls the inside / outside air ratio adjustment unit to decrease a ratio of the outside air in accordance with the increased air volume of the blower, and thereafter, when a concentration of carbon dioxide in the vehicle cabin is less than a second threshold, controls the inside / outside air ratio adjustment unit to further decrease the ratio of the outside air.

5. 4. The vehicle air conditioning system according to claim 3, wherein the control unit controls the blower to increase an air volume when a concentration of harmful substances inside the vehicle cabin is equal to or higher than the first threshold value and a concentration of harmful substances outside the vehicle cabin is equal to or higher than the first threshold value, and controls the inside / outside air ratio adjustment unit to decrease a ratio of the outside air in accordance with the increased air volume of the blower, and thereafter controls the inside / outside air ratio control unit to increase the ratio of the outside air when a concentration of carbon dioxide in the vehicle cabin is equal to or higher than a second threshold value.

6. The vehicle air conditioning device according to any one of claims 1 to 5, wherein the control unit determines whether the filter has deteriorated based on a concentration of harmful substances inside the vehicle cabin, a concentration of harmful substances outside the vehicle cabin, an air volume of the blower, and the inside / outside air ratio.

7. 7. The vehicle air conditioning system of claim 6, wherein the control unit calculates a concentration of harmful substances in the air before passing through the filter based on the concentration of harmful substances inside the vehicle cabin, the concentration of harmful substances outside the vehicle cabin, the air volume of the blower, and the inside / outside air ratio, calculates a filter efficiency for the harmful substances based on the calculated concentration of harmful substances in the air before passing through the filter and the concentration of harmful substances in the vehicle cabin, and determines that the filter is deteriorated if the calculated filter efficiency is less than a judgment threshold.

8. 7. The vehicle air conditioner according to claim 6, further comprising a notification unit that issues a notification to encourage cleaning or replacement of the filter when the control unit determines that the filter is deteriorated.

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