Vehicle air conditioning device

Abstract

[Problem] To suppress an increase in energy consumption while keeping the concentration of carbon dioxide in a cabin within a suitable range. [Solution] A vehicle air conditioning device 1 capable of performing ventilation in the cabin comprises: a concentration detection sensor 14a for detecting the concentration of carbon dioxide in the cabin; and a control device 13 for controlling ventilation in the cabin so that the concentration of carbon dioxide in the cabin is kept within a range from a lower limit value to an upper limit value. The risk to a human body such as nausea and dizziness due to a high concentration of carbon dioxide can be avoided by performing the ventilation so that the concentration of carbon dioxide in the cabin is equal to or less than the upper limit value. Unnecessary ventilation is avoided by performing the ventilation so that the concentration of carbon dioxide in the cabin is equal to or greater than the lower limit value.

Description

Vehicle air conditioning system

[0001] The present invention relates to an air conditioning system for a vehicle.

[0002]

[0003] A vehicle air conditioner capable of ventilating a vehicle cabin is known. An increase in the concentration of carbon dioxide in the vehicle cabin can reduce comfort. For this reason, for example, Patent Document 1 discloses a technology for optimally ventilating carbon dioxide.

[0003] JP 2023-124516 A

[0004] An object of the present invention is to provide a vehicle air conditioner that can suppress an increase in energy consumption while keeping the carbon dioxide concentration in the vehicle cabin within an appropriate range.

[0005] According to one aspect of the present invention, a vehicle air conditioning system is a vehicle air conditioning system capable of ventilating the vehicle cabin, and is equipped with a concentration detection unit that detects the concentration of carbon dioxide in the vehicle cabin, and a ventilation control unit that controls the ventilation in the vehicle cabin so that the concentration of carbon dioxide in the vehicle cabin falls within a range between a lower limit value and an upper limit value.

[0006] According to the present invention, it is possible to provide a vehicle air conditioner that can suppress an increase in energy consumption while keeping the carbon dioxide concentration in the vehicle cabin within an appropriate range.

[0007] FIG. 1 is a functional block diagram showing the overall configuration of a vehicle air conditioner. FIG. 2 is an explanatory diagram showing a specific example of creating a ventilation permission area in a vehicle air conditioner. FIG. 3 is a diagram showing a specific example of performing ventilation in a vehicle air conditioner. FIG. 4 is a diagram showing an example of a flowchart showing the procedure for ventilation control processing in a vehicle air conditioner. FIG. 5 is a diagram showing an example of a flowchart showing the procedure for ventilation means selection processing in a vehicle air conditioner. FIG. 6 is a diagram showing an example of a flowchart showing the procedure for ventilation plan creation processing in a vehicle air conditioner. FIG. 7 is a diagram showing an example of a ventilation plan in a vehicle air conditioner. FIG. 8 is a diagram showing an example of a ventilation plan in a vehicle air conditioner. FIG. 9 is a diagram showing an example of a flowchart showing the procedure for ventilation plan adjustment processing in a vehicle air conditioner. FIG. 10 is a diagram showing a specific example of adjusting the ventilation plan in a vehicle air conditioner. FIG. 11 is a diagram showing an example of a flowchart showing the procedure for ventilation plan adjustment processing in a vehicle air conditioner. FIG. 12 is a diagram showing a specific example of adjusting the ventilation plan in a vehicle air conditioner. FIG. 13 is a diagram showing a specific example of adjusting the ventilation plan in a vehicle air conditioner. FIG. 14 is a diagram showing an example of a flowchart illustrating the procedure for ventilation plan adjustment processing in a vehicle air conditioner. FIG. 15 is a diagram showing a specific example when a ventilation plan is adjusted in a vehicle air conditioner. FIG. 16 is a diagram showing an example of a flowchart illustrating the procedure for ventilation plan adjustment processing in a vehicle air conditioner. FIG. 17 is a diagram showing a specific example when a ventilation plan is adjusted in a vehicle air conditioner. FIG. 18 is a diagram showing a specific example when a ventilation plan is adjusted in a vehicle air conditioner. FIG. 19 is a diagram showing an example of a flowchart illustrating the procedure for ventilation plan adjustment processing in a vehicle air conditioner. FIG. 20 is a diagram showing a specific example when a ventilation plan is adjusted in a vehicle air conditioner. FIG. 21 is a diagram showing an example of a flowchart illustrating the procedure for ventilation plan adjustment processing in a vehicle air conditioner. FIG. 22 is a diagram showing a specific example when a ventilation plan is adjusted in a vehicle air conditioner. FIG. 23 is a diagram showing an example of a flowchart illustrating the procedure for air conditioning control processing in a vehicle air conditioner. FIG. 24 is a diagram showing a specific example when pre-cooling is performed before ventilation in a vehicle air conditioner.Fig. 25 is a flowchart showing an example of a procedure for ventilation control processing in a vehicle air conditioner. Fig. 26 is a diagram showing a specific example of setting a target value for carbon dioxide concentration in a vehicle air conditioner.

[0008] [Configuration of Vehicle Air Conditioner] The vehicle air conditioner of this embodiment is configured to be able to suppress an increase in energy consumption while keeping the carbon dioxide concentration in the vehicle cabin within an appropriate range.

[0009] FIG. 1 is an explanatory diagram showing an outline of a configuration example of a vehicle air conditioner 1 according to this embodiment.

[0010] The vehicle air conditioner 1 conditions the passenger compartment of an electric vehicle (EV) such as an electric vehicle or a hybrid vehicle, and also regulates the temperature of a battery and a traction motor mounted in the vehicle.

[0011] The vehicle air conditioner 1 includes a heat medium circuit 10 through which a heat medium circulates, a refrigerant circuit 11 through which a refrigerant circulates, an HVAC (Heating, Ventilation, and Air Conditioning) unit 12 that supplies air for air conditioning to the interior of the vehicle, and a control device 13 that controls the operation of the vehicle air conditioner 1 based on detection values ​​of various sensors, various requests, etc.

[0012] The heat medium circuit 10 includes a cooler core, a heater core, a motor, a battery, etc. The refrigerant circuit 11 includes a compressor, a pressure reducing device, etc. The HVAC unit 12 includes a blower 12a. The heat medium circulating through the heat medium circuit 10 exchanges heat with the refrigerant circulating through the refrigerant circuit 11, and the blower 12a blows air into the vehicle cabin via the heater core and cooler core, thereby controlling the temperature inside the vehicle cabin.

[0013] The HVAC unit 12 includes an intake unit 12b as an inside / outside air switching device. The intake unit 12b adjusts the ratio of opening and closing between an outside air intake port that introduces outside air into the vehicle cabin and an inside air intake port that introduces inside air into the vehicle cabin to a desired ratio. This allows the ratio of outside air (outside air intake) and inside air (inside air circulation) introduced into the HVAC unit 12 to be adjusted. Note that the configurations of the heat medium circuit 10 and the refrigerant circuit 11 are not limited to those of this embodiment.

[0014] The control device 13 is a microcomputer equipped with a processor, a memory, and an input / output interface.

[0015] The vehicle air conditioner 1 is equipped with sensors 14 that detect the temperatures inside and outside the vehicle cabin, as well as the temperatures and pressures of various parts of the refrigerant circuit 3. The sensors 14 include a concentration detection sensor 14a that measures the concentration of carbon dioxide in the vehicle cabin, an interior air temperature sensor 14b that measures the temperature of the air in the vehicle cabin, an outside air temperature sensor 14c that detects the outside air temperature, a blown-out temperature sensor 14d that detects the temperature of the air blown into the vehicle cabin, and a weight sensor 14e that detects the weight of each seat installed in the vehicle cabin. Data on the concentration of carbon dioxide in the vehicle cabin, data on the interior temperature, data on the outside air temperature, data on the blown-out temperature, and data on the detected weight of the occupants are input to the control device 13.

[0016] The control device 13 is connected to various devices installed in the heat medium circuit 10 and the refrigerant circuit 11, and the blower 12a and intake unit 12b of the HVAC unit 12. The control device 13 can control the air conditioning in the vehicle cabin by controlling the operation of the various devices installed in the heat medium circuit 10 and the refrigerant circuit 11, and the blower 12a and intake unit 12b of the HVAC unit 12. The control device 13 can also control the ventilation in the vehicle cabin by controlling the operation of the intake unit 12b to control the proportion of outside air introduced.

[0017] An operation unit 15 is also connected to the control device 13. By operating the operation unit 15, an occupant can switch the air conditioning on or off, adjust the temperature in the vehicle cabin, and so on. An operation signal output by operating the operation unit 15 is input to the control device 13. The control device 13 displays operation information from the operation unit on a display unit 16 such as a display, and also outputs the information via a speaker 17.

[0018] The control device 13 can also communicate with an ECU of a power window device 19 via a communication bus 18. The control device 13 can control ventilation in the vehicle cabin by controlling the opening of the vehicle windows via the power window device 19.

[0019] Furthermore, the control device 13 can transmit and receive data (such as estimated arrival time data, driving route data, and weather information data) to and from the ECU of a navigation device 20 installed in the vehicle via the communication bus 18. The control device 13 can also obtain necessary data (such as vehicle speed) from other ECUs (not shown) in the vehicle via the communication bus 18.

[0020] [Ventilation Control in Vehicle Air Conditioning Devices] In order to prevent risks to the occupants' bodies, it is necessary to ventilate the vehicle cabin so that the carbon dioxide concentration in the vehicle cabin falls within a predetermined range. On the other hand, if the amount of outside air introduced is increased to reduce the carbon dioxide concentration in the vehicle cabin, the air conditioning load increases in order to bring the temperature in the vehicle cabin closer to a target temperature. For example, the compressor rotation speed increases in order to bring the temperature in the vehicle cabin closer to the target temperature. An increase in the air conditioning load increases energy consumption, which affects the vehicle's mileage. Therefore, in order to reduce energy consumption while keeping the carbon dioxide concentration in the vehicle cabin within a predetermined range that does not pose a risk to the occupants' health, it is necessary to introduce outside air into the vehicle cabin at an appropriate timing. In other words, it is necessary to optimize the ventilation timing.

[0021] For this reason, the ventilation timing of the vehicle interior is controlled to optimize the ventilation timing in the vehicle air conditioner 1. Hereinafter, a specific ventilation control in the vehicle air conditioner 1 will be described.

[0022] In this embodiment, a permissible range of carbon dioxide concentration in the vehicle cabin from when the occupants board the vehicle until the vehicle arrives at the destination is defined as a ventilation permission range. Ventilation is performed so that the carbon dioxide concentration in the vehicle cabin falls within the range defined by the ventilation permission range. This prevents risk to the human body caused by the carbon dioxide concentration in the vehicle cabin exceeding an upper limit, while controlling ventilation so that the carbon dioxide concentration in the vehicle cabin is maintained at a lower limit (≒ outside air) to avoid unnecessary ventilation.

[0023] Specifically, the control device 13 includes, as its functional parts, a carbon dioxide increase rate calculation part 13a, an estimated arrival time acquisition part 13b, a target value setting part 13c, a threshold setting part 13d, and a ventilation permission area creation part 13e.

[0024] The carbon dioxide increase rate calculation unit 13a determines the change in carbon dioxide concentration after the occupant boards the vehicle based on the change in carbon dioxide concentration in the vehicle cabin detected by the concentration detection sensor 14a, and calculates the rate of increase in carbon dioxide concentration in the vehicle cabin based on the change in carbon dioxide concentration after the occupant boards the vehicle.

[0025] The estimated arrival time acquisition unit 13b acquires the estimated arrival time required for the vehicle to arrive at the destination from the time the occupant boards the vehicle, from the navigation device 20. The navigation device 20 calculates the estimated arrival time based on the route to the destination set by the occupant, traffic congestion information, and the like.

[0026] The target value setting unit 13c sets a target value for the concentration of carbon dioxide in the vehicle cabin when the vehicle arrives at the destination. For example, the target value is set to the upper limit of the concentration of carbon dioxide in the cabin.

[0027] The threshold setting unit 13d sets the carbon dioxide concentration that changes when the carbon dioxide concentration in the vehicle cabin rises from the lower limit value and reaches the target value at the scheduled arrival time based on the rate of increase calculated by the carbon dioxide increase rate calculation unit 13a as the threshold.

[0028] The ventilation permission region creating unit 13e creates a ventilation permission region that defines the allowable range of the carbon dioxide concentration in the vehicle cabin so that the allowable range of the carbon dioxide concentration in the vehicle cabin changes from a range of not less than a lower limit and not more than an upper limit to a range of not less than a threshold and not more than an upper limit depending on the running time of the vehicle. Note that the threshold is not less than the lower limit, so it can be said that in the ventilation permission region, the carbon dioxide concentration in the vehicle cabin falls within a range not less than a lower limit and not more than an upper limit.

[0029] Next, an example of creating a ventilation permission area will be described with reference to FIG.

[0030] 2 , the carbon dioxide increase rate calculation unit 13a calculates the increase rate a of the carbon dioxide concentration in the vehicle cabin based on the actual measurement value v of the change in the carbon dioxide concentration in the vehicle cabin. Then, the threshold setting unit 13d sets the threshold b based on the increase rate a calculated by the carbon dioxide increase rate calculation unit 13a, the estimated arrival time t1 acquired by the estimated arrival time acquisition unit 13b, and the target value TG set by the target value setting unit 13c. Specifically, the carbon dioxide concentration that changes at the increase rate a from the lower limit of the carbon dioxide concentration in the vehicle cabin to the target value TG at the estimated arrival time t1 is set as the threshold b.

[0031] The ventilation permission area creating unit 13e defines the area surrounded by the upper limit of the carbon dioxide concentration in the vehicle cabin of 3000 ppm, the lower limit of the carbon dioxide concentration in the vehicle cabin of 450 ppm, and the threshold value b as the ventilation permission area A.

[0032] By ventilating the vehicle cabin so that the carbon dioxide concentration falls within a range of a lower limit of 450 ppm or more and an upper limit of 3000 ppm or less, harm to the health of the occupants can be avoided.

[0033] Furthermore, by ventilating the vehicle interior so that the carbon dioxide concentration does not fall below the threshold value b, it is possible to prevent the carbon dioxide concentration from falling below the target value TG when the vehicle arrives at the destination. This eliminates the need for ventilation more than necessary, thereby avoiding unnecessary ventilation.

[0034] Furthermore, because the lower limit of 450 ppm is equivalent to the carbon dioxide concentration in the outside air, increasing the ventilation rate will not cause the carbon dioxide concentration in the vehicle cabin to fall below the lower limit of 450 ppm. In other words, increasing the ventilation rate even after the carbon dioxide concentration in the vehicle cabin has reached the lower limit of 450 ppm will result in wasted ventilation. Therefore, by not performing ventilation to maintain the lower limit of 450 ppm in the ventilation permission area A, it is possible to avoid performing more ventilation than necessary and avoid wasted ventilation.

[0035] 2, when the vehicle is driven to the destination at a rate of increase a predicted from the actual measured value v of the carbon dioxide concentration in the vehicle cabin, it is predicted that the carbon dioxide concentration in the vehicle cabin will rise to 7750 ppm. If the target value TG for the carbon dioxide concentration in the vehicle cabin upon arrival at the destination is set to an upper limit of 3000 ppm based on this predicted value, it is possible to determine that 4750 ppm of carbon dioxide, which is the difference between the predicted value 7750 ppm and the target value 3000 ppm, needs to be released into the outside air by the time the vehicle arrives at the destination.

[0036] As described above, exceeding the upper limit in the ventilation permission area A may pose a risk to the human body, potentially harming the health of the occupants. On the other hand, if ventilation is performed in the ventilation permission area A so that the concentration falls below the threshold or is maintained at the lower limit, unnecessary ventilation increases energy consumption. Therefore, it is preferable to exhaust 4750 ppm of carbon dioxide while ventilating the vehicle cabin so that the carbon dioxide concentration in the vehicle cabin falls within the range specified in the ventilation permission area A.

[0037] In this example, an upper limit value for the carbon dioxide concentration in the vehicle cabin is set to 3000 ppm, and an example of a lower limit value for the carbon dioxide concentration in the vehicle cabin is set to 450 ppm, but the upper and lower limit values ​​do not have to be limited to the values ​​shown in this embodiment.

[0038] In addition, when creating the ventilation permission area, instead of setting a threshold value, the ventilation permission area may be created using an upper limit value and a lower limit value, and ventilation may be performed so that the carbon dioxide concentration in the vehicle cabin falls within a range below the upper limit value and above the lower limit value.

[0039] FIG. 3 shows a specific example of actual ventilation.

[0040] As shown in Figure 3, to perform ventilation, first, the actual carbon dioxide concentration (CO2 concentration in the figure) is measured from the time the occupant boards the vehicle until a predetermined time (e.g., 5 minutes) has elapsed. The rate of increase in the carbon dioxide concentration in the vehicle cabin is predicted based on the measured actual value, and the carbon dioxide concentration when the vehicle arrives at the destination is predicted based on the predicted rate of increase. Then, a ventilation permission area is created in the manner described above. In addition, by calculating the difference between the carbon dioxide concentration when the vehicle arrives at the destination and a target value (in this example, the upper limit), the carbon dioxide concentration that needs to be reduced by ventilation can be identified.

[0041] Here, by keeping the carbon dioxide concentration in the vehicle cabin below the upper limit, risks to the human body, such as nausea and dizziness, caused by high carbon dioxide concentrations can be avoided.

[0042] On the other hand, when ventilation is performed, the amount of outside air introduced into the vehicle cabin increases, which increases the difference between the target outlet temperature and the actual outlet temperature when blowing air into the vehicle cabin. As a result, the air conditioning load often increases in order to reduce the temperature difference between the two.

[0043] Furthermore, even if the ratio of outside air introduction is set to 100%, the carbon dioxide concentration in the vehicle cabin will not fall below the lower limit, i.e., the carbon dioxide concentration of the outside air. Therefore, if the vehicle cabin is ventilated so that the carbon dioxide concentration in the vehicle cabin maintains the lower limit, ventilation will be performed even though the carbon dioxide concentration will not fall. In this case, the ventilation time (i.e., the time for introducing outside air) will be increased more than necessary, resulting in an increase in the operating time of the vehicle air conditioner 1 with a high air conditioning load. Therefore, the energy consumption of the vehicle air conditioner 1 will increase.

[0044] Therefore, as shown in Figure 3, by performing ventilation so that the carbon dioxide concentration inside the vehicle cabin falls within the range specified by the ventilation permission area, it is possible to keep the carbon dioxide concentration inside the vehicle cabin within an appropriate range that does not harm the health of the occupants, while avoiding unnecessary ventilation, thereby reducing the introduction of more outside air than necessary and suppressing an increase in energy consumption.

[0045] <Ventilation Control Process> FIG. 4 is a flowchart showing an example of the procedure of ventilation control process by the control device 13.

[0046] 4, the control device 13 determines whether or not it is possible to predict the destination of the vehicle (S1). Specifically, it determines whether or not it is possible to predict the vehicle's travel route and travel time based on data from the navigation device 20 and past travel data held by the navigation device 20. The past travel data is, for example, an accumulation of data on regular travel such as commuting to work or school.

[0047] When the control device 13 determines that it is possible to predict the destination (S1: Yes), it measures the rate of increase of the carbon dioxide concentration (CO2 concentration in the figure) in the vehicle cabin based on the actual measured value of the carbon dioxide concentration in the vehicle cabin detected by the concentration detection sensor 14a (S2).

[0048] Next, the control device 13 predicts the increase in the concentration of carbon dioxide in the vehicle cabin when the vehicle arrives at the destination (S3). Specifically, the control device 13 predicts the increase in the concentration of carbon dioxide in the vehicle cabin when the vehicle arrives at the destination based on the estimated arrival time to the destination predicted in step S1 and the increase rate predicted from the increase rate of the concentration of carbon dioxide in the vehicle cabin measured in step S2.

[0049] Next, the control device 13 creates a ventilation permission area based on the estimated arrival time to the destination predicted in step S1, the rate of increase predicted from the rate of increase of carbon dioxide concentration in the vehicle cabin measured in step S2, the upper and lower limits of the carbon dioxide concentration in the vehicle cabin, an arbitrarily set target value for the carbon dioxide concentration in the vehicle cabin, and a threshold value set from these (S4).

[0050] Next, the control device 13 executes processing for executing an optimal ventilation mode in which ventilation is performed so that the carbon dioxide concentration in the vehicle cabin falls within the ventilation permission range created in step S4 according to the driving time (S5). Note that, since the ventilation amount and ventilation time differ depending on the ventilation method, the control device 13 selects the ventilation method and ventilation time so that the carbon dioxide concentration in the vehicle cabin falls within the ventilation permission range. Note that the control device 13 may suggest the ventilation method to the occupant.

[0051] On the other hand, when the control device 13 determines that it is not possible to predict the destination (S1: No), it measures the rate of increase in the carbon dioxide concentration in the vehicle cabin based on the actual measured value of the carbon dioxide concentration in the vehicle cabin detected by the concentration detection sensor 14a (S6).

[0052] Next, the control device 13 determines whether or not there is a possibility that the concentration of carbon dioxide in the vehicle cabin will exceed the upper limit (S7). If it is determined that there is no possibility that the concentration of carbon dioxide in the vehicle cabin will exceed the upper limit (S7: No), the control device 13 repeats the determination of step S7. On the other hand, if there is a possibility that the concentration of carbon dioxide in the vehicle cabin will exceed the upper limit (S7: Yes), the control device 13 performs ventilation of the vehicle cabin (S8).

[0053] Next, the control device 13 determines whether the concentration of carbon dioxide in the vehicle cabin is at the lower limit (S9). If it is determined that the concentration of carbon dioxide in the vehicle cabin is not at the lower limit (S9: No), the control device 13 repeats the determination of step S9. That is, ventilation is continued. If the control device 13 determines that the concentration of carbon dioxide in the vehicle cabin is at the lower limit (S9: Yes), the control device 13 returns to step S7.

[0054] <Ventilation means> Examples of ventilation means include increasing the amount of outside air introduced, opening windows, and opening and closing doors. Each ventilation means has the following characteristics.

[0055] When selecting an increase in the amount of outside air introduced, the amount of outside air introduced must be at least greater than the increase in carbon dioxide in the vehicle cabin. Increasing the amount of outside air introduced, such as introducing 100% outside air, increases the air conditioning load but can reduce the carbon dioxide concentration in a short period of time. On the other hand, decreasing the amount of outside air introduced can suppress the increase in air conditioning load but lengthens the ventilation time. Furthermore, reducing the amount of outside air introduced can reduce the temperature change when switching to a ventilation mode that performs ventilation, thereby preventing a decrease in passenger comfort. The temperature change when switching to a ventilation mode can also be varied by changing the fan rotation speed.

[0056] When opening the windows is selected, the rate at which the carbon dioxide concentration decreases varies depending on factors such as the window opening area and the vehicle speed, but while driving, it is possible to reduce the carbon dioxide concentration more quickly than when the HVAC unit 12 is operating with 100% outside air intake. On the other hand, because the air supplied to the vehicle cabin does not pass through the HVAC unit 12, if there is a large temperature difference between the air conditioning set temperature and the outside air temperature, it is expected that passenger comfort will decrease and the air conditioning load will increase.

[0057] Door opening and closing is a ventilation method that is assumed when picking up or dropping off passengers in a taxi, etc. Door opening and closing is done when passengers get in and out, and is characterized by ventilation with a larger opening area than opening a window. Because the vehicle is stopped, passengers move from outside the vehicle to inside the vehicle, depending on the direction of the outside air, so a large amount of ventilation can be expected.

[0058] <Ventilation Means Selection Process> Fig. 5 is a flowchart showing the ventilation means selection process by the control device 13. The control device 13 can execute this process to select ventilation means when performing ventilation in step S5 of the ventilation control process in Fig. 4.

[0059] 5, the control device 13 determines whether the target blow-out temperature is higher than the outside air temperature (S1). That is, by determining whether the outside air temperature is higher than the target blow-out temperature, it determines whether heating operation or cooling operation is being performed. Note that if the target blow-out temperature and the outside air temperature are the same, the process may branch to either step S2 or step S7.

[0060] If the target blowout temperature is higher than the outside air temperature (S1: Yes), i.e., in the case of heating operation, it is determined whether the outside air temperature is higher than the inside air temperature (S2). If the outside air temperature is lower than the inside air temperature (S2: No), the control device 13 sets the permissible range a of the ventilation means. Specifically, as the permissible range of the ventilation means, the permissible range of outside air introduction is set to 0% to 100%, and the permissible range of ventilation by opening a window is set to 0% (S3).

[0061] If the outside air temperature is higher than the inside air temperature (S2: No), the control device 13 determines whether or not there is a window opening restriction (S4). If the control device 13 determines that there is a window opening restriction (S4: Yes), the control device 13 sets an allowable range b of the ventilation means. Specifically, the allowable range for introducing outside air is set to 0% to 100%, and if opening the window does not allow rain or snow to enter the vehicle cabin, the allowable range for ventilation by opening the window is set to 0% to 5% even in bad weather, and if the air quality is poor, the allowable range for ventilation by opening the window is set to 0% (S5).

[0062] If the control device 13 determines that there is no restriction on window opening (S4: No), the control device 13 sets the permissible range c of the ventilation means. Specifically, the permissible range for introducing outside air is set to 0% to 100%, and the permissible range for ventilation by opening the windows is set to 0% to 100% (S6).

[0063] If the target blowout temperature is lower than the outside air temperature (S1: No), i.e., in the case of cooling operation, it is determined whether the outside air temperature is higher than the inside air temperature (S7). If the outside air temperature is higher than the inside air temperature (S7: Yes), the control device 13 sets the permissible range a of the ventilation means. Specifically, as the permissible range of the ventilation means, the permissible range of outside air introduction is set to 0% to 100%, and the permissible range of ventilation by opening a window is set to 0% (S8).

[0064] If the outside air temperature is higher than the inside air temperature (S7: No), the control device 13 determines whether or not there is a window opening restriction (S9). If the control device 13 determines that there is a window opening restriction (S9: Yes), the control device 13 sets an allowable range b of the ventilation means. Specifically, the allowable range for introducing outside air is set to 0% to 100%, and if opening the window does not allow rain or snow to enter the vehicle cabin, the allowable range for ventilation by opening the window is set to 0% to 5% even in bad weather, and if the air quality is poor, the allowable range for ventilation by opening the window is set to 0% (S10).

[0065] If the control device 13 determines that there is no restriction on window opening (S9: No), the control device 13 sets the permissible range c of the ventilation means. Specifically, the permissible range for introducing outside air is set to 0% to 100%, and the permissible range for ventilation by opening the windows is set to 0% to 100% (S11).

[0066] As described above, by selecting the ventilation means, ventilation can be performed taking into consideration the ventilation efficiency and the comfort of the occupants.

[0067] <Ventilation Plan Creation Process> FIG. 6 is a flowchart of the ventilation plan creation process executed by the control device 13.

[0068] As shown in FIG. 6 , the control device 13 calculates the ventilation rate from the time the occupants board the vehicle until the vehicle arrives at the destination based on a preset ventilation rate (S1). The minimum ventilation rate is calculated as the ventilation rate. The ventilation rate is determined by subtracting the lower limit of the carbon dioxide concentration in the vehicle cabin from the upper limit of the carbon dioxide concentration in the vehicle cabin. This predetermined ventilation rate is set as the upper limit of the carbon dioxide concentration to be reduced by ventilating the vehicle cabin. That is, the ventilation rate in each ventilation is fixed at a constant ventilation rate. The ventilation rate is then calculated based on the carbon dioxide amount calculated from the difference between the carbon dioxide concentration in the vehicle cabin at the time the vehicle arrives at the destination and the target value, and the carbon dioxide amount that can be reduced by one ventilation. The minimum ventilation rate is determined by performing the ventilations calculated by the above calculation plus one ventilation to compensate for the remaining carbon dioxide concentration that was not fully discharged by this ventilation.

[0069] Next, the control device 13 creates a ventilation plan so that the concentration of carbon dioxide in the vehicle cabin falls within the ventilation permission range and ventilation is performed the number of times calculated in step S1 (S2).

[0070] 7 shows a specific example of a ventilation plan in which the carbon dioxide concentration to be reduced by each ventilation is set as the difference between an upper limit and a lower limit. In this example, the upper limit is set as the target value. Similarly to FIG. 2, an example is also shown in which a ventilation permission area is created using an increase rate a and a threshold value b.

[0071] For example, the difference between the upper limit of 3000 ppm and the lower limit of 450 ppm is 2550 ppm, and the carbon dioxide concentration at the time the vehicle reaches its destination is 7750 ppm, so the increase in carbon dioxide concentration from the upper limit of 3000 ppm at the time the vehicle reaches its destination is 4750 ppm.

[0072] In this case, the amount of carbon dioxide that needs to be released to the outside air is calculated based on the increase in carbon dioxide concentration when the vehicle reaches its destination. The amount of carbon dioxide that can be released in one ventilation is also predicted. The control device 13 stores data regarding the amount of carbon dioxide released per unit time for each ventilation mode and data regarding the time it takes for the carbon dioxide concentration to decrease from the upper limit to the lower limit. The amount of carbon dioxide that can be released in one ventilation can be predicted by multiplying the amount of carbon dioxide released per unit time by the time it takes for the carbon dioxide concentration to decrease from the upper limit to the lower limit. The ventilation rate can then be calculated based on the amount of carbon dioxide that needs to be released to the outside air and the amount of carbon dioxide that can be released in one ventilation. In this example, if a full ventilation is performed once to reduce the carbon dioxide concentration in the vehicle cabin from the upper limit to the lower limit, and then another ventilation is performed to ventilate the remaining 2,200 ppm, it is possible to ventilate 4,750 ppm. Therefore, a total of two ventilations, including the remaining ventilation, can be determined as the minimum ventilation rate. Therefore, the calculated ventilation rate based on the ventilation volume per ventilation is two.

[0073] 8 shows a specific example of a ventilation plan in which the carbon dioxide concentration to be reduced by one ventilation is set to a fixed value less than the difference between the upper and lower limits. In this example, the upper limit is set as the target value. Similarly to FIG. 2, an example is also shown in which a ventilation permission area is created using an increase rate a and a threshold value b.

[0074] As shown in Figure 8, for example, the carbon dioxide concentration reduced by 2300 ppm per ventilation is 7750 ppm when the vehicle reaches its destination, and the increase in carbon dioxide concentration from the upper limit of 3000 ppm when the vehicle reaches its destination is 4750 ppm.

[0075] In this case, the amount of carbon dioxide that needs to be released to the outside air is calculated based on the increase in carbon dioxide concentration at the time the vehicle arrives at its destination. The amount of carbon dioxide that can be released in one ventilation session is also predicted. The control device 13 stores data related to the amount of carbon dioxide released per unit time for each ventilation mode. The amount of carbon dioxide that can be released in one ventilation session can be predicted by multiplying the amount of carbon dioxide released per unit time by the time required for one ventilation session. The ventilation rate can then be calculated based on the amount of carbon dioxide that needs to be released to the outside air and the amount of carbon dioxide that can be released in one ventilation session. In this example, if two fixed ventilation sessions are performed to reduce the carbon dioxide concentration in the vehicle cabin by 2,300 ppm per session, and then one ventilation session is performed to ventilate the remaining 150 ppm, it is possible to ventilate 4,750 ppm. Therefore, a total of three ventilation sessions, including the remaining ventilation, can be determined as the minimum ventilation rate. Therefore, the calculated ventilation rate based on the ventilation volume per session is three.

[0076] As described above, the carbon dioxide concentration in the vehicle cabin can be kept within an acceptable range with the minimum necessary ventilation frequency, thereby suppressing an increase in energy consumption.

[0077] <Ventilation plan adjustment process> After creating the ventilation plan as described above, the control device 13 adjusts the ventilation plan so that it is an appropriate ventilation plan depending on the vehicle driving environment. Specific examples of ventilation plan adjustment processes by the control device 13 will be described below. Note that, although multiple ventilation plan adjustment processes will be described, only one process may be executed, or multiple processes may be executed in combination.

[0078] <Specific Example 1 of Ventilation Plan Adjustment Processing> FIG. 9 is a flowchart of ventilation plan adjustment processing executed by the control device 13.

[0079] As shown in Fig. 9, the control device 13 creates a ventilation plan (S1). For example, the control device 13 creates a ventilation plan based on a single ventilation volume from when the occupants board the vehicle until the vehicle arrives at the destination (see Figs. 6 to 8).

[0080] Next, the control device 13 predicts changes in the outside air temperature along the travel route (S2) based on, for example, travel route information and weather information acquired from the navigation device 20, weather information acquired through mutual communication with oncoming vehicles, and the like.

[0081] Next, the control device 13 adjusts the ventilation plan based on the result of the prediction in step S2 (S3). Specifically, the ventilation plan is adjusted so that the ventilation volume increases when the outside air temperature approaches the target temperature in the vehicle cabin.

[0082] Fig. 10 shows a specific example of adjusting the ventilation plan based on a predicted change in outdoor air temperature. Note that Fig. 10 shows an example when cooling operation is in progress. In addition, an example of creating a ventilation permission area using the rate of increase a and threshold b, similar to Fig. 2, will be described.

[0083] As shown in FIG. 10(a), for example, a ventilation plan is created based on the ventilation volume per one time from when the passengers board until the vehicle arrives at the destination (see FIGS. 6 to 8).

[0084] Next, as shown in Figure 10(b), based on the driving route information to the destination and weather information, changes in outside temperature along the route to the destination are predicted. For example, for sections (1) to (5) on the driving route, changes in outside temperature are predicted as follows: Driving near water: Low outside temperature Urban and suburban areas: Temperatures in urban areas are higher than those in suburban areas Effect of altitude: The higher the altitude, the lower the outside temperature Effect of solar radiation: The outside temperature in sunny areas is higher than that in shaded areas

[0085] As shown in FIG. 10(b), for example, assume that the driving route to the destination acquired from the driving route information consists of the following sections (1) to (5): (1): Driving from shade to sunshine (2): Approaching a waterside on the driving route (3): Driving along the waterside (4): Driving through an urban area (5): Driving toward a destination on high ground

[0086] In this case, it can be predicted that the outside temperature will rise in section (1), drop halfway through section (2), rise halfway through section (3), drop halfway through section (4), and drop halfway through section (5).

[0087] As shown in Fig. 10(c), an arbitrary threshold value (for example, set to an approximate median value of the outside air temperature change) is set at which the outside air temperature approaches the target temperature inside the vehicle cabin. Then, when the outside air temperature exceeds the threshold value and approaches the target temperature, the ventilation plan shown in Fig. 10(a) is adjusted so that the amount of outside air introduced increases. This reduces the air conditioning load.

[0088] In section (4), the outside air temperature exceeds the threshold and does not approach the target temperature. However, if ventilation is not performed, the carbon dioxide concentration in the vehicle cabin will exceed the upper limit. Therefore, ventilation is performed at a lower volume than in sections (2) and (3) so that the carbon dioxide concentration in the vehicle cabin does not exceed the upper limit.

[0089] As described above, by creating the ventilation plan shown in Figure 10(a) and predicting the change in outside temperature shown in Figure 10(b), and then adjusting the ventilation plan as shown in Figure 10(c) based on the predicted change in outside temperature, it is possible to suppress an increase in energy consumption.

[0090] The increase in energy consumption can be effectively suppressed by increasing the ventilation volume when the outside temperature is below a threshold and decreasing the ventilation volume when the outside temperature is above the threshold. In particular, when the outside temperature is below a threshold, ventilation that reduces the carbon dioxide concentration in the vehicle cabin from the upper limit to the lower limit can maximize the effect of suppressing the increase in energy consumption.

[0091] Although Figure 10 has been described using the example of cooling operation, when heating operation is performed, the increase in energy consumption can be effectively suppressed by increasing the ventilation volume when the outside air temperature rises and approaches the target temperature inside the vehicle cabin.

[0092] As described above, by performing ventilation at a location close to the target temperature inside the vehicle cabin, the air conditioning load during ventilation can be reduced, and an increase in energy consumption can be suppressed.

[0093] In this embodiment, an example has been given in which changes in outside air temperature are predicted and the ventilation volume is increased when the outside air temperature approaches the target temperature inside the vehicle cabin. However, it is also possible to monitor changes in outside air temperature in real time and increase the ventilation volume when the outside air temperature approaches the target temperature inside the vehicle cabin based on the monitoring results.

[0094] <Specific Example 2 of Ventilation Plan Adjustment Processing> FIG. 11 is a flowchart of ventilation plan adjustment processing executed by the control device 13.

[0095] As shown in Fig. 11, the control device 13 creates a ventilation plan (S1). For example, the control device 13 creates a ventilation plan based on a single ventilation volume from when the occupants board the vehicle until the vehicle arrives at the destination (see Figs. 6 to 8).

[0096] Next, the control device 13 predicts the timing of a cooling request for the on-board heat-generating devices (S2). For example, the control device 13 predicts the temperature change of the on-board heat-generating devices based on the outside air temperature at the time of vehicle startup, predictions of changes in outside air temperature based on route information and weather information acquired by the navigation device 20, and pre-owned data on temperature changes of the on-board heat-generating devices, and predicts the timing of a cooling request for the on-board heat-generating devices. Examples of on-board heat-generating devices include the battery and the motor.

[0097] Next, the control device 13 adjusts the ventilation plan so as to change at least one of the ventilation timing and the ventilation volume in response to the cooling request of the in-vehicle heat-generating device (S3). That is, the ventilation plan is adjusted so as to change at least one of the ventilation timing and the ventilation volume of the ventilation plan created in step S1 based on the cooling request timing predicted in step S2. For example, the ventilation plan is adjusted so as not to ventilate the vehicle cabin at the cooling request timing of the in-vehicle heat-generating device.

[0098] Fig. 12 shows a specific example of adjusting the ventilation plan based on the predicted timing of the battery cooling request. Note that Fig. 12 shows an example when air conditioning operation is in progress. Similar to Fig. 2, an example of creating a ventilation permission area using the increase rate a and threshold b will be described.

[0099] As shown in FIG. 12(a), for example, a ventilation plan is created based on the ventilation volume per one time from when the passengers board until the vehicle arrives at the destination (see FIGS. 6 to 8).

[0100] Next, as shown in FIG. 12( b), the timing of a battery cooling request is predicted. The battery temperature needs to be regulated to stay within a temperature range suitable for use. This is because battery temperature exceeding the upper limit may lead to battery degradation, and battery temperature exceeding the lower limit may limit the power that the battery can output. For example, the timing of a battery cooling request from when the occupants board the vehicle until the vehicle arrives at the destination is predicted as follows for sections (1) to (5) on the travel route: (1): When the vehicle is started, the battery temperature is approximately equal to the outside air temperature, so battery cooling is requested. (2): The battery has cooled down to the lower limit of the battery temperature, so the battery cooling request is canceled. (3): The battery temperature is near the upper limit of the battery temperature, so battery cooling is requested. (4): The battery cooling request is canceled. (5): The battery temperature is near the upper limit of the battery temperature, so battery cooling is requested.

[0101] As described above, the control device 13 controls the switching of the battery cooling mode between the upper and lower limits so that the battery temperature is between the upper and lower limits for temperature management. Specifically, the control device 13 controls the switching of the battery cooling mode by switching the flow path in the heat medium circuit 10, etc.

[0102] In the sections (1) and (4) where the battery cooling request is released, the carbon dioxide concentration in the vehicle cabin decreases from the upper limit to the lower limit, and in the section (3), the ventilation timing and ventilation volume are changed to suppress the decrease in concentration more than in the sections (1) and (4) so ​​that the carbon dioxide concentration in the vehicle cabin does not reach the upper limit.

[0103] When performing air conditioning operation, both the battery cooling request and the air conditioning request require cold energy. When the battery is cooled, the air conditioning load increases, such as an increase in the compressor's rotation speed. On the other hand, when ventilation is performed, the temperature inside the vehicle cabin deviates from the target temperature, which increases the air conditioning load, such as an increase in the compressor's rotation speed. Therefore, by setting the timing of battery cooling and the timing of the increase in the air conditioning load due to ventilation at different times, the air conditioning load, such as the load on the compressor, can be averaged and the shortened mechanical life of the compressor and other components can be suppressed. Furthermore, when battery cooling and ventilation are performed at the same time, the increase in battery power consumption due to the increase in compressor rotation speed and other factors is greater than when the two are performed at different times. Furthermore, as the amount of heat generated by the battery increases, the energy consumed to cool the battery also increases. Therefore, by performing battery cooling and ventilation at different times during air conditioning operation, the increase in required power and the increase in energy consumption can be suppressed.

[0104] Fig. 13 shows a specific example of adjusting the ventilation plan based on the predicted timing of the battery cooling request. Note that Fig. 13 shows an example when heating operation is performed. Also, as in Fig. 2, an example of creating a ventilation permission area using the increase rate a and threshold b will be described.

[0105] As shown in FIG. 13(a), for example, a ventilation plan is created based on the ventilation volume per one time from when the occupants board until the vehicle arrives at the destination (see FIGS. 6 to 8).

[0106] Next, as shown in FIG. 13( b), the timing of a battery cooling request is predicted. Battery cooling is necessary for the reasons described above. For example, the timing of a battery cooling request from when the occupants board the vehicle until the vehicle arrives at the destination is predicted as follows for sections (1) to (5) on the travel route. Note that the battery is warmed up, for example, by heating the heat medium using a heat medium heating device provided in the heat medium circuit 10. (1): When the vehicle is started, the battery temperature is approximately equal to the outside air temperature, so the battery is warmed up. (2): The battery has been warmed up to the upper limit of the battery temperature, so the battery is cooled in response to a battery cooling request. (3): The battery temperature is near the lower limit, so the battery cooling request is canceled. (4): The battery has been warmed up to the upper limit of the battery temperature, so the battery is cooled in response to a battery cooling request. (5): The battery temperature is near the lower limit, so the battery cooling request is canceled.

[0107] As described above, the control device 13 controls the battery cooling mode switching between the upper and lower limits so that the battery temperature is between the upper and lower limits for temperature management. Specifically, the control device 13 controls the battery cooling mode switching by switching the flow path in the heat medium circuit 10, etc.

[0108] In the sections (2) and (4) where the battery cooling request is released, the carbon dioxide concentration in the vehicle cabin decreases from the upper limit to the lower limit or threshold value, and in the section (1), the ventilation timing and ventilation volume are changed to suppress the decrease in concentration more than in the sections (2) and (4) so ​​that the carbon dioxide concentration in the vehicle cabin does not reach the upper limit.

[0109] When heating operation is performed, cold heat is required to fulfill the battery cooling request, and warm heat is required to fulfill the air conditioning request. Furthermore, when a battery cooling request is not issued, the battery is not warmed, and therefore the battery's waste heat cannot be used as a heat source for air conditioning. Therefore, when a battery cooling request is not issued, the compressor rotation speed increases, and the air conditioning load increases. If ventilation is performed at this time, the temperature inside the vehicle cabin will deviate from the target temperature, further increasing the compressor rotation speed, further increasing the air conditioning load. On the other hand, when a battery cooling request is issued, the battery's waste heat can be used as a heat source for air conditioning. Therefore, when a battery cooling request is issued, the compressor rotation speed decreases, and the air conditioning load decreases. Therefore, when heating operation is performed, battery cooling and ventilation can be performed at the same time, thereby reducing energy consumption compared to when battery cooling and ventilation are performed at different times.

[0110] As described above, the simultaneous occurrence of an increase in air conditioning load and a request for battery temperature control can be prevented, thereby suppressing an increase in power consumption throughout the vehicle. In addition, the occurrence of a high load on the compressor can be prevented, thereby suppressing a reduction in the compressor's lifespan.

[0111] In this embodiment, an example is given of predicting the timing of a battery cooling request, but it is also possible to monitor in real time whether a battery cooling request has occurred, and change the timing of ventilating the vehicle interior or the amount of ventilation when ventilating the vehicle interior when a battery cooling request has occurred.

[0112] <Specific Example 3 of Ventilation Plan Adjustment Processing> FIG. 14 is a flowchart of ventilation plan adjustment processing executed by the control device 13.

[0113] As shown in Fig. 14, the control device 13 creates a ventilation plan (S1). For example, the control device 13 creates a ventilation plan based on a single ventilation volume from when the occupants board the vehicle until the vehicle arrives at the destination (see Figs. 6 to 8).

[0114] Next, the control device 13 predicts changes in air quality along the travel route (S2) based on, for example, map information (industrial areas, tunnels, cedar avenues, etc.) held by the navigation device 20 and traffic information (traffic congestion information) obtained via V2X (Vehicle to X).

[0115] At this time, the control device 13 outputs proposal information to the navigation device 20, suggesting to the occupant a driving route that will not deteriorate the air quality (S3). The navigation device 20 proposes a different driving route to the occupant based on the received proposal information. This allows the occupant to set a desired route, thereby preventing factors that may harm the occupant's health from entering the cabin. If a different driving route is selected by the occupant, the process of step S1 is performed again.

[0116] Next, the control device 13 adjusts the ventilation plan based on the air quality along the travel route (S4). Specifically, the control device 13 adjusts the ventilation plan so as to change at least one of the ventilation timing and the ventilation amount in sections of the travel route where the air quality is poor.

[0117] Whether the air quality is poor or not is determined based on an air quality index determined based on the concentration of pollutants. That is, a predetermined threshold is set for determining whether the air quality is poor or not, and whether the air quality is poor or not is determined based on whether the air quality index exceeds the threshold. If the air quality index exceeds the threshold, the air quality is determined to be poor, and if the air quality index is equal to or less than the threshold, the air quality is determined to be good or fair. Examples of pollutants used to determine the air quality index include PM10, PM2.5, ozone, particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide.

[0118] Fig. 15 shows a specific example of adjusting the ventilation plan based on a predicted change in air quality along the travel route. Note that, as in Fig. 2, an example will be described in which the ventilation permission area is created based on the increase rate a and the threshold b.

[0119] As shown in FIG. 15(a), for example, a ventilation plan is created based on the ventilation volume per one time from when the occupants board until the vehicle arrives at the destination (see FIGS. 6 to 8).

[0120] Next, as shown in FIG. 15( b), changes in air quality along the driving route are predicted. Specifically, changes in air quality along the driving route are predicted based on map information (industrial areas, tunnels, cedar-lined streets, etc.) and traffic information (traffic congestion information) obtained via V2X. As a result, for example, the following predictions are made for sections (1) to (5) along the driving route: (1): Driving starts from home, with little traffic and average air quality; (2): Driving on a tree-lined street, with pollen flying around; (3): Driving through an open area after leaving the tree-lined street, with good air quality; (4): Driving in a tunnel results in poor air quality due to congestion in the tunnel and exhaust fumes from vehicles ahead; (5): Driving through the tunnel and traffic congestion, with good air quality after leaving the suburbs.

[0121] If the air quality index exceeds the threshold and the air quality deteriorates, it is preferable not to perform ventilation because this will have a negative impact on occupants. Therefore, if it is predicted that the air quality index will exceed the threshold, ventilation is performed before the air quality exceeds the threshold.

[0122] 15(c), ventilation is performed until the carbon dioxide concentration in the vehicle cabin falls to the lower limit or the threshold of the ventilation permission area in sections (1), (3), and (5) where the air quality index is below the threshold, and ventilation timing and ventilation volume are changed so that ventilation is not performed in sections (2) and (4) where the air quality index exceeds the threshold. In this way, by reducing the carbon dioxide concentration in the vehicle cabin to the lower limit in sections where the air quality index is below the threshold, air conditioning by internal air recirculation can be performed without hindrance in sections where the air quality index exceeds the threshold.

[0123] If the ventilation volume is insufficient even when ventilation is performed as much as possible in a section where the air quality index is equal to or less than the threshold, it is preferable to perform ventilation control so that the ventilation volume is minimized in a section where the air quality index exceeds the threshold. The minimum ventilation volume in a section where the air quality index exceeds the threshold is, for example, the ventilation volume at which the carbon dioxide concentration in the vehicle cabin rises from the upper limit value to a level at which ventilation is required as soon as the air quality index enters the section below the threshold.

[0124] Furthermore, if the air quality index on the route always exceeds the threshold, it is difficult to ventilate the route without harming the health of the occupants, so it is preferable to notify the driver of this fact and suggest an alternative route, for example, by using an in-vehicle display, a voice message, or a warning light.

[0125] As described above, by not ventilating sections with poor air quality, it is possible to prevent factors that harm the health of passengers in the vehicle cabin from entering the vehicle.

[0126] In this embodiment, an example has been given in which changes in air quality along the travel route are predicted and the timing of ventilating the vehicle interior or the amount of ventilation when ventilating the vehicle interior is changed in sections where the air quality deteriorates. However, it is also possible to monitor the air quality in real time and, based on the monitoring results, change the timing of ventilating the vehicle interior or the amount of ventilation when ventilating the vehicle interior in sections where the air quality deteriorates.

[0127] <Specific Example 4 of Ventilation Plan Adjustment Processing> FIG. 16 is a flowchart of ventilation plan adjustment processing executed by the control device 13.

[0128] As shown in Fig. 16, the control device 13 creates a ventilation plan (S1). For example, the control device 13 creates a ventilation plan based on a ventilation volume per one time from when the occupants board the vehicle until the vehicle arrives at the destination (see Figs. 6 to 8).

[0129] Next, the control device 13 determines whether information about a change in the number of occupants in the vehicle cabin has been input (S2). Information about a change in the number of occupants in the vehicle cabin is input, for example, when a change in the number of occupants is detected by the seat weight sensor 14e included in the sensor 14. Information about a change in the number of occupants in the vehicle cabin is also input, for example, when a change in the number of occupants is predicted along a travel route when a route is set in the navigation device 20 (for example, when a stop is made at a kindergarten or school) or a taxi is reserved. Note that information about a change in the number of occupants in the vehicle cabin may also be input when a change in the number of occupants is detected by other means, such as opening and closing a door, fastening and unfastening a seatbelt, or image analysis of the vehicle cabin.

[0130] Next, if the control device 13 determines that information on a change in the number of occupants in the vehicle compartment has been input (S2: Yes), it recreates the ventilation permission area and recreates the ventilation plan created in step S1 (S3).If the control device 13 determines that information on a change in the number of occupants in the vehicle compartment has not been input (S2: No), it repeats the determination in step S2.

[0131] FIG. 17 shows a specific example of recreating a ventilation plan based on information on a change in the number of occupants in the vehicle cabin that is input when the change in the number of occupants in the vehicle cabin cannot be predicted.

[0132] As shown in Figure 17(a), for example, a ventilation permission area is created using the rate of increase a and threshold b as in Figure 2, and then a ventilation plan is created from the time the occupants board until the vehicle arrives at the destination based on the ventilation volume per ventilation (see Figures 6 to 8).

[0133] Next, as shown in FIG. 17B, a change in the number of occupants in the vehicle cabin is identified. For example, the change in the number of occupants is identified by a seat weight sensor 14e included in the sensor 14. The change in the number of occupants may also be detected by other means, such as door opening / closing, fastening / unfastening of seat belts, or image analysis of the vehicle cabin. Furthermore, any one of these detection means may be used alone, or a combination of multiple means may be used. Furthermore, since the rate of increase in the carbon dioxide concentration in the vehicle cabin is measured again when the ventilation plan is re-created, it is not necessary to identify the change in the number of occupants as long as it is possible to detect at least that a change in the number of occupants has occurred.

[0134] As a result of identifying the change in the number of occupants in the vehicle, for example, suppose that the number of occupants changes as follows for sections (1) to (2) on the driving route: (1): The number of occupants is one from the start of driving until a predetermined time. (2) Before arriving at the destination, the number of occupants increases by one, and the vehicle heads to the destination with two occupants.

[0135] 17(c), in the section (1) where there is one occupant, a ventilation plan (solid line in the figure) is created so that the concentration of carbon dioxide in the vehicle cabin falls within the ventilation permission area created using the increase rate a, threshold value b, upper and lower limits predicted based on the concentration of carbon dioxide in the vehicle cabin measured at the start of driving. In the section (2) where there are two occupants, the number of occupants has increased to two, so the concentration of carbon dioxide in the vehicle cabin is measured again, and a ventilation plan (dashed line in the figure) is recreated so that the concentration of carbon dioxide in the vehicle cabin falls within the ventilation permission area recreated using the increase rate c, threshold value d, upper and lower limits predicted based on the measured carbon dioxide concentration.

[0136] In this example, when the number of occupants changes, the carbon dioxide concentration in the vehicle cabin has a margin up to the upper limit, so the ventilation-permitted area is recreated without ventilation. However, if the carbon dioxide concentration in the vehicle cabin does not have a margin up to the upper limit when the number of occupants changes, or if there are a large number of passengers, it is preferable to perform ventilation after detecting the change in the number of occupants, reduce the carbon dioxide concentration in the vehicle cabin to near the lower limit, and then measure the carbon dioxide concentration in the vehicle cabin again and recreate the ventilation-permitted area.

[0137] FIG. 18 shows a specific example of recreating a ventilation plan based on information on a change in the number of occupants in the vehicle cabin that is input when a change in the number of occupants in the vehicle cabin can be predicted.

[0138] As shown in Figure 18(a), for example, a ventilation permission area is created using the rate of increase a and threshold b as in Figure 2, and then a ventilation plan is created from the time the occupants board until the vehicle arrives at the destination based on the ventilation volume per ventilation (see Figures 6 to 8).

[0139] Next, as shown in FIG. 18(b), changes in the number of occupants are predicted based on taxi reservations and route settings (passing by kindergartens and schools) using the navigation device 20. As a result of predicting changes in the number of occupants in the vehicle, for example, it is predicted that the number of occupants will change as follows for sections (1) to (2) on the driving route: (1): From the start of driving to the school, there is one occupant, the driver. (2): The driver picks up a child from school, increasing the number of occupants by one, and then returns home with two occupants.

[0140] As shown in FIG. 18( c), in the section (1) where the number of occupants is predicted to be one, a ventilation plan (solid line in the figure) is created so that the carbon dioxide concentration in the vehicle cabin falls within the ventilation permission area created using the increase rate a, threshold value b, upper limit value, and lower limit value predicted based on the carbon dioxide concentration in the vehicle cabin measured at the start of driving. In this case, the ventilation plan is created so that ventilation is performed before the number of occupants increases and the carbon dioxide concentration in the vehicle cabin falls near the lower limit value. Therefore, the carbon dioxide concentration in the vehicle cabin can be measured again immediately after the number of occupants increases. Then, in the section (2) where the number of occupants is predicted to be two, the carbon dioxide concentration in the vehicle cabin is measured again, and a ventilation plan (dashed line in the figure) is recreated so that the carbon dioxide concentration in the vehicle cabin falls within the ventilation permission area recreated using the increase rate c, threshold value d, upper limit value, and lower limit value predicted based on the measured carbon dioxide concentration.

[0141] As described above, ventilation can be performed at the optimal timing even if the number of occupants increases or decreases, so unnecessary ventilation can be prevented.

[0142] <Specific Example 5 of Ventilation Plan Adjustment Processing> FIG. 19 is a flowchart of ventilation plan adjustment processing executed by the control device 13.

[0143] As shown in Fig. 19, the control device 13 creates a ventilation plan (S1). For example, the control device 13 creates a ventilation plan based on a single ventilation volume from when the occupants board the vehicle until the vehicle arrives at the destination (see Figs. 6 to 8).

[0144] Next, the control device 13 monitors the relationship between the cabin temperature, the outside air temperature, and the target cabin temperature in real time while the vehicle is running, and determines whether the outside air temperature is closer to the target cabin temperature than the cabin temperature (S2). That is, during heating operation, the control device 13 determines whether the relationship: target cabin temperature > outside air temperature > cabin temperature holds. During cooling operation, the control device 13 determines whether the relationship: target cabin temperature < outside air temperature < cabin temperature holds.

[0145] Next, if the control device 13 determines that the outside air temperature is closer to the target interior temperature than the interior temperature of the vehicle (S2: Yes), it performs ventilation so that the carbon dioxide concentration in the vehicle interior maintains the lower limit value (S3). Ventilation is performed by appropriate means such as introducing outside air or opening a window. Furthermore, if the control device 13 determines that the outside air temperature is not closer to the target interior temperature than the interior temperature of the vehicle (S2: No), it ends the process.

[0146] Next, the control device 13 determines whether the temperature inside the vehicle cabin is closer to the target temperature inside the vehicle cabin than the outside air temperature (S4). Note that if the temperature inside the vehicle cabin and the outside air temperature are the same, it is determined that the temperature inside the vehicle cabin is closer to the target temperature inside the vehicle cabin than the outside air temperature. That is, during heating operation, it determines whether the relationship: target temperature inside the vehicle cabin > interior temperature ≥ outside air temperature is established. During cooling operation, it determines whether the relationship: target temperature inside the vehicle cabin < interior temperature ≤ outside air temperature is established.

[0147] Next, if the control device 13 determines that the temperature inside the vehicle cabin is closer to the target temperature inside the vehicle cabin than the outside air temperature (S4: Yes), it recreates the ventilation permission area and recreates the ventilation plan created in step S1 (S5).If the control device 13 determines that the temperature inside the vehicle cabin is not closer to the target temperature inside the vehicle cabin than the outside air temperature (S4: No), it continues the processing of step S3.

[0148] Fig. 20 shows a specific example of recreating a ventilation plan when the outside air temperature is closer to the target temperature inside the vehicle cabin than the temperature inside the vehicle cabin. Fig. 20 shows a specific example of cooling operation. Similar to Fig. 2 , an example of creating a ventilation permission area using the increase rate a and threshold b will be described.

[0149] As shown in FIG. 20(a), for example, a ventilation plan is created based on the ventilation volume per one time from when the passengers board until the vehicle arrives at the destination (see FIGS. 6 to 8).

[0150] Next, as shown in FIG. 20( b), the temperature inside the vehicle cabin (T1 in the figure) and the outside air temperature are constantly measured, and the relationship between the temperature inside the vehicle cabin, the outside air temperature, and the target temperature inside the vehicle cabin is monitored in real time while the vehicle is traveling. For example, assume that the temperature inside the vehicle cabin is 55°C when an occupant gets in, and the temperature inside the vehicle cabin is higher than the outside air temperature. In this case, the outside air temperature is closer to the target temperature inside the vehicle cabin than the temperature inside the vehicle cabin. Thereafter, the temperature inside the vehicle cabin decreases due to the introduction of the outside air temperature and the air conditioning inside the vehicle cabin. However, in section (1) on the travel route, the temperature inside the vehicle cabin is higher than the outside air temperature, and the outside air temperature is closer to the target temperature inside the vehicle cabin than the temperature inside the vehicle cabin. Then, in section (2), the outside air temperature becomes higher than the temperature inside the vehicle cabin, and the temperature inside the vehicle cabin becomes closer to the target temperature inside the vehicle cabin than the outside air temperature.

[0151] As shown in FIG. 20( c), when the temperature changes as described above, ventilation control is performed as described below in section (1) where the outside air temperature is closer to the target interior temperature than the interior temperature. Then, in section (2) where the interior temperature is closer to the target interior temperature than the outside air temperature, the ventilation permission area is re-created using the increase rate a and threshold b, as in FIG. 20( a), and the ventilation plan is re-created, and ventilation control is performed as described below in section (2). Therefore, in the initially created ventilation permission area, the carbon dioxide concentration that needs to be discharged is 4750 ppm, which is the difference between 7750 ppm and the target value of 3000 ppm. In the re-created ventilation permission area, the carbon dioxide concentration that needs to be discharged changes to 3000 ppm, which is the difference between 6000 ppm and the target value of 3000 ppm. Ventilation control is performed by adjusting the inside / outside air ratio using the HVAC unit 12 or by opening windows. (1): Ventilation is performed so that the carbon dioxide concentration in the interior is maintained at the lower limit until the relationship of the target interior temperature < the inside air temperature ≦ the outside air temperature is established. (2) Increase the amount of internal air circulation and ventilate to reduce the air conditioning load.

[0152] In this example, in the section (1) where the outside air temperature is closer to the target temperature inside the vehicle cabin than the temperature inside the vehicle cabin, the amount of outside air introduced is increased until the temperature inside the vehicle cabin falls below the outside air temperature. Therefore, the carbon dioxide concentration inside the vehicle cabin is maintained at the lower limit. By setting the carbon dioxide concentration inside the vehicle cabin at the lower limit, the ventilation frequency can be reduced to three times compared to four times in the initial ventilation plan shown in Figure 20(a).

[0153] In addition, under conditions where the outside air temperature is closer to the target temperature inside the vehicle cabin than the temperature inside the vehicle cabin, bringing the introduced outside air closer to the target temperature inside the vehicle cabin can reduce the air conditioning load rather than bringing the air inside the vehicle cabin when passengers get in closer to the target temperature inside the vehicle cabin, thereby reducing energy consumption more than starting operation with internal air circulation.

[0154] Although the cooling operation has been described as an example, the same process is performed during heating operation. Examples of situations in which the process of this example is performed include when getting into the vehicle on a midsummer day, when getting into the vehicle after leaving it in the sun or shade for a long period of time during the middle of the season, and in the early morning hours in winter.

[0155] As described above, by maintaining the carbon dioxide concentration in the vehicle cabin at the lower limit, it is possible to avoid performing ventilation immediately after the temperature in the vehicle cabin reaches the target temperature. Therefore, it is possible to prevent the temperature in the vehicle cabin from deviating from the target temperature immediately after the temperature in the vehicle cabin reaches the target temperature, thereby preventing a decrease in comfort. Furthermore, by exchanging outside air with the air in the vehicle cabin during start-up operation, it is possible to reduce the air conditioning load during start-up operation when the outside air temperature is closer to the target temperature in the vehicle cabin than the temperature in the vehicle cabin. Furthermore, it is possible to reduce the number of ventilations and the amount of ventilation performed after start-up operation, thereby suppressing an increase in energy consumption.

[0156] <Specific Example 6 of Ventilation Plan Adjustment Processing> FIG. 21 is a flowchart of ventilation plan adjustment processing executed by the control device 13.

[0157] As shown in Fig. 21, the control device 13 creates a ventilation plan (S1). For example, the control device 13 creates a ventilation plan based on a single ventilation volume from when the occupants board the vehicle until the vehicle arrives at the destination (see Figs. 6 to 8).

[0158] Next, the control device 13 monitors the relationship between the cabin temperature, the outside air temperature, and the target cabin temperature in real time while the vehicle is running, and determines whether the outside air temperature is closer to the target cabin temperature than the cabin temperature (S2). That is, during heating operation, the control device 13 determines whether the relationship: target cabin temperature > outside air temperature > cabin temperature holds. During cooling operation, the control device 13 determines whether the relationship: target cabin temperature < outside air temperature < cabin temperature holds.

[0159] Next, if the control device 13 determines that the outside air temperature is closer to the target interior temperature than the interior temperature of the vehicle (S2: Yes), it performs ventilation so that the carbon dioxide concentration in the vehicle interior maintains the lower limit value (S3). Ventilation is performed by appropriate means such as introducing outside air or opening a window. On the other hand, if the control device 13 determines that the outside air temperature is not closer to the target interior temperature than the interior temperature of the vehicle (S2: No), it proceeds to step S4.

[0160] Next, the control device 13 determines whether the temperature inside the vehicle cabin is closer to the target temperature inside the vehicle cabin than the outside air temperature (S4). Note that if the temperature inside the vehicle cabin and the outside air temperature are the same, it is determined that the temperature inside the vehicle cabin is closer to the target temperature inside the vehicle cabin than the outside air temperature. That is, during heating operation, it determines whether the relationship: target temperature inside the vehicle cabin > interior temperature ≥ outside air temperature is established. During cooling operation, it determines whether the relationship: target temperature inside the vehicle cabin < interior temperature ≤ outside air temperature is established.

[0161] Next, if the control device 13 determines that the temperature inside the vehicle cabin is closer to the target temperature inside the vehicle cabin than the outside air temperature (S4: Yes), it recreates the ventilation permission area and recreates the ventilation plan created in step S1 (S5).If the control device 13 determines that the temperature inside the vehicle cabin is not closer to the target temperature inside the vehicle cabin than the outside air temperature (S4: No), it continues the processing of step S3.

[0162] The control device 13 then determines whether the temperature inside the vehicle cabin matches the target temperature and whether the temperature difference between the temperature inside the vehicle cabin and the outside air temperature is equal to or less than a predetermined temperature (S6). At this time, even if the temperature inside the vehicle cabin does not perfectly match the target temperature, it is determined that they match as long as the temperature difference is within an allowable range.

[0163] If the control device 13 determines that the cabin temperature matches the target temperature and that the temperature difference between the cabin temperature and the outside air temperature is not equal to or less than the predetermined temperature (S6: No), the control device 13 adjusts the ventilation plan so that the ventilation time per ventilation session is shorter than the ventilation volume initially set in the ventilation plan created in step S1 (S7). That is, the ventilation plan is adjusted to perform ventilation at a first ventilation volume, which has a shorter ventilation time per ventilation session and a smaller ventilation volume than the ventilation volume initially set in the ventilation plan created in step S1. On the other hand, if the control device 13 determines that the cabin temperature matches the target temperature and that the temperature difference between the cabin temperature and the outside air temperature is equal to or less than the predetermined temperature (S6: Yes), the control device 13 adjusts the ventilation plan so that the ventilation time per ventilation session is longer than the first ventilation volume (S8). That is, the ventilation plan is adjusted to perform ventilation at a second ventilation volume, which has a longer ventilation time per ventilation session and a larger ventilation volume than the first ventilation volume.

[0164] When performing ventilation at the first ventilation volume or the second ventilation volume, only one of the ventilation time or the ventilation volume may be changed.

[0165] Fig. 22 shows a specific example of recreating a ventilation plan based on the cabin temperature, the outside air temperature, and the target cabin temperature. Fig. 22 shows a specific example of cooling operation. Similar to Fig. 2 , an example of creating a ventilation permission area using a rise rate a and a threshold value b will be described.

[0166] As shown in FIG. 22(a), for example, a ventilation plan is created based on the ventilation volume per one time from when the occupants board until the vehicle arrives at the destination (see FIGS. 6 to 8).

[0167] Next, as shown in FIG. 22( b), the vehicle interior temperature (T1 in the figure) and the outside air temperature (T2 in the figure) are constantly measured, and the relationship between the vehicle interior temperature, the outside air temperature, and the target vehicle interior temperature is monitored in real time while the vehicle is traveling. For example, assume that the outside air temperature is approximately 35°C when an occupant gets in the vehicle, and the vehicle interior temperature is higher than the outside air temperature. That is, in section (1) on the travel route, the vehicle interior temperature is higher than the outside air temperature, and the outside air temperature is closer to the target vehicle interior temperature than the vehicle interior temperature. Then, in section (2), the outside air temperature becomes higher than the vehicle interior temperature, and the vehicle interior temperature is closer to the target vehicle interior temperature than the outside air temperature. In this case, in section (2), the deviation between the vehicle interior temperature and the target temperature is large in the first half, and the temperature difference between the outside air temperature and the vehicle interior temperature exceeds a predetermined temperature (e.g., 10°C) in the second half. Then, in section (3), the vehicle interior temperature reaches the target temperature, and the temperature difference between the outside air temperature and the vehicle interior temperature is equal to or less than a predetermined temperature (e.g., 10°C).

[0168] Then, as shown in Figure 22 (c), the inside and outside air temperatures and the target temperature are detected at the first ventilation timing after the occupant gets in, and the ventilation time and ventilation volume are adjusted based on the temperature difference between the temperature inside the vehicle cabin and the outside air temperature, and the temperature difference between the temperature inside the vehicle cabin and the target temperature.

[0169] That is, in the section (1) where the outside air temperature is closer to the target interior temperature than the interior temperature of the vehicle, ventilation is controlled as in (1) below. Then, in the section (2) where the interior temperature is closer to the target interior temperature than the outside air temperature but the deviation between the interior temperature and the target temperature is large and the temperature difference between the outside air temperature and the interior temperature exceeds a predetermined temperature, the ventilation permission area is recreated using the increase rate a and threshold b as in Figure 22(a) , and the ventilation plan is recreated, and ventilation is controlled as in (2) below. Therefore, in the initially created ventilation permission area, the carbon dioxide concentration that needs to be released is 4750 ppm, which is the difference between 7750 ppm and the target value of 3000 ppm. In the recreated ventilation permission area, the carbon dioxide concentration that needs to be released changes to 3000 ppm, which is the difference between 6000 ppm and the target value of 3000 ppm. Furthermore, in section (3) where the temperature inside the vehicle cabin reaches the target temperature and the temperature difference between the outside air temperature and the temperature inside the vehicle cabin is equal to or less than a predetermined temperature (e.g., 10°C), ventilation is controlled as follows: (1): Because the temperature inside the vehicle cabin is greater than the outside air temperature during cooling operation, ventilation is performed so that the carbon dioxide concentration inside the vehicle cabin maintains a lower limit value. (2): Because the outside air temperature is greater than the temperature inside the vehicle cabin. However, in the first half of this section, the deviation between the temperature inside the vehicle cabin and the target temperature is large, and in the second half of this section, the temperature difference between the outside air temperature and the temperature inside the vehicle cabin exceeds a predetermined value. Therefore, it is determined that extending the ventilation time and reducing the ventilation volume would likely result in a decrease in occupant comfort. Therefore, the ventilation time is shortened compared to the ventilation time initially set in the ventilation plan shown in FIG. 22(a) and the ventilation volume is reduced compared to the ventilation volume initially set in the ventilation plan shown in FIG. 22(a). (3): Because the temperature inside the vehicle cabin reaches the target temperature and the temperature difference between the outside air temperature and the temperature inside the vehicle cabin is equal to or less than a predetermined value, it is determined that extending the ventilation time and increasing the ventilation volume would not result in a decrease in occupant comfort. Therefore, the ventilation time per ventilation is set longer than in section (2), and the ventilation volume per ventilation is set larger than in section (2).

[0170] Although the temperature inside the vehicle cabin rises slightly at the timing of ventilation, as shown in the temperature change inside the vehicle cabin in Figure 22 (b), by adjusting the ventilation time and ventilation volume, the amount of temperature rise inside the vehicle cabin can be kept within a range that does not impair comfort.

[0171] As described above, a ventilation plan is created after determining the time and amount of ventilation that can be performed without affecting the comfort of the occupants, so that deterioration of the comfort of the occupants can be suppressed.

[0172] <Air Conditioning Control Process> When ventilation is performed, the temperature difference between the interior temperature and the target temperature tends to increase, which reduces the comfort of the occupants. Therefore, in consideration of the comfort of the occupants, it is necessary to shorten the ventilation time, which makes it difficult to ensure a sufficient ventilation volume. Therefore, in this embodiment, in order to solve these problems, it is possible to perform air conditioning control in accordance with the ventilation plan. Specifically, the control device 13 can execute the air conditioning control process shown in FIG. 23.

[0173] FIG. 23 is a flowchart of the air conditioning control process executed by the control device 13.

[0174] As shown in Fig. 23, the control device 13 creates a ventilation plan (S1). For example, the control device 13 creates a ventilation plan based on a single ventilation volume from when the occupants board the vehicle until the vehicle arrives at the destination (see Figs. 6 to 8).

[0175] Next, the control device 13 determines whether or not it is the timing before the start of ventilation based on the ventilation plan created in step S1 (S2).

[0176] Next, if it is not the timing before the start of ventilation (S2: No), the control device 13 repeats the determination in step S2. That is, if ventilation is being performed, the control device 13 repeats the determination.

[0177] If the timing is before ventilation starts (S2: Yes), the control device 13 pre-cools or pre-heats the air in the vehicle cabin (S3). That is, pre-cooling is performed during cooling operation, and pre-heating is performed during heating operation. For example, during cooling operation, pre-cooling is performed to lower the temperature in the vehicle cabin by a predetermined temperature (e.g., 1°C) below the target temperature. During heating operation, pre-heating is performed to raise the temperature in the vehicle cabin by a predetermined temperature (e.g., 1°C) above the target temperature.

[0178] Next, the control device 13 determines whether it is time to start ventilation (S4). If it is not time to start ventilation (S4: No), the control device 13 continues pre-cooling or pre-heating (S3). If it is time to start ventilation (S4: Yes), the control device 13 ends pre-cooling or pre-heating (S5).

[0179] Next, the control device 13 determines whether the scheduled arrival time at the destination has arrived (S6). If the scheduled arrival time has not arrived (S6: No), the process returns to step S2. If the scheduled arrival time has arrived (S6: Yes), the process ends.

[0180] FIG. 24 shows a specific example of pre-cooling the air in the vehicle compartment before ventilation during cooling operation.

[0181] As shown in FIG. 24(a), for example, a ventilation plan is created based on the ventilation volume per one time from when the occupants board until the vehicle arrives at the destination (see FIGS. 6 to 8).

[0182] Next, as shown in FIG. 24(b), the temperature inside the vehicle cabin is measured, and the relationship between the temperature inside the vehicle cabin and the target temperature is monitored in real time. Then, based on the ventilation plan shown in FIG. 24(a), the air inside the vehicle cabin is pre-cooled to lower the temperature inside the vehicle cabin by a predetermined temperature below the target temperature. Specifically, the air inside the vehicle cabin is pre-cooled before ventilation begins, and pre-cooling is terminated when ventilation begins. This allows the temperature inside the vehicle cabin to be maintained within a range of "target temperature ±α." Therefore, even if the temperature inside the vehicle cabin changes due to ventilation, the impact on passenger comfort can be suppressed. Furthermore, since pre-cooling is a prerequisite, the compressor can be controlled so that its rotation speed always fluctuates at a constant rate. Therefore, the target rotation speed of the compressor does not fluctuate frequently, thereby reducing the load on the compressor.

[0183] In this embodiment, an example has been given in which the timing of ventilation is determined in advance based on a ventilation plan and then pre-cooling or pre-heating is performed before ventilation. However, if the timing of ventilation cannot be predicted in advance, the timing of ventilation may be predicted from the tendency of an increase in the carbon dioxide concentration in the vehicle cabin, and pre-cooling or pre-heating may be performed based on the predicted result.

[0184] As described above, the temperature difference between the interior temperature and the target temperature is kept within a predetermined range, so the ventilation time can be extended while suppressing discomfort to occupants. In addition, since the ventilation volume can be secured, the ventilation frequency can be reduced, and the load on the compressor, etc. can be reduced.

[0185] <Target Value Setting Process> If the carbon dioxide concentration in the vehicle cabin is controlled to be near the upper limit value at the time of arrival at the destination in order to reduce energy consumption, this may affect the behavior of the occupants after getting out of the vehicle. Therefore, it is preferable to set the target value by predicting the behavior of the occupants after getting out of the vehicle. Therefore, the control device 13 can execute the ventilation control process shown in Figure 24.

[0186] Fig. 25 is a flowchart of the ventilation control process executed by the control device 13. Note that the process other than step 3a is the same as that in Fig. 4, and therefore a description thereof will be omitted.

[0187] As shown in FIG. 25, the control device 13 executes steps S1 to S3 and then proceeds to step S3a. In step S3a, the occupant's behavior is predicted and a target value is set (S3a). For example, the occupant's behavior is predicted based on the destination and route set in the navigation device 20, the occupant's behavior pattern, and the like. Specifically, the occupant's behavior is predicted based on whether or not the occupant is commuting to school or work. A target value (e.g., 1000 ppm) that makes the occupant feel comfortable is then set as the target value. This allows the occupant to exit the vehicle in a comfortable mood and proceed to their post-exit behavior.

[0188] Next, the control device 13 creates a ventilation permission area based on the target value set in step S3a (S4). After that, the same processing as in FIG.

[0189] 26A and 26B show specific examples of ventilation permission areas that are created when target values ​​are set based on predicted occupant behavior. Similar to FIG. 2, an example of creating a ventilation permission area using an increase rate a and a threshold value b will be described. An example of creating a ventilation permission area B will be described in FIG. 26A, and an example of creating a ventilation permission area C will be described in FIG. 26B.

[0190] As shown in FIG. 26( a), the method for creating the ventilation permission area B is similar to the method for creating the ventilation permission area A (see FIG. 2) described with reference to FIG. 2. However, it differs from the ventilation permission area A in that the target value TG is set to a value lower than the upper limit value. The target value is lower than the upper limit value and is a concentration that is effective for making the occupants feel comfortable. In the example shown in FIG. 26( a), the carbon dioxide concentration that transitions when the carbon dioxide concentration in the vehicle cabin reaches the target value TG from the upper limit value at the estimated arrival time t1 is set as the threshold value e, based on the rate of decrease in the carbon dioxide concentration when ventilation is performed. In the ventilation permission area B, the allowable range of the carbon dioxide concentration in the vehicle cabin is set to be equal to or higher than the threshold value b and equal to or lower than the threshold value e just before arrival at the destination.

[0191] However, if the carbon dioxide concentration in the vehicle cabin reaches the target value as soon as the vehicle arrives at the destination, as in ventilation permission area B, the passengers may not feel comfortable while riding, so this is not effective in making the passengers feel comfortable after disembarking.

[0192] For this reason, as shown in FIG. 26( b), it is preferable to create a ventilation permission area C in which the carbon dioxide concentration in the vehicle cabin is set to a target value or less a predetermined time before arrival at the destination. The method for creating the ventilation permission area C is similar to the method for creating the ventilation permission area A described with reference to FIG. 2. However, the ventilation permission area C differs from the ventilation permission area A in that the target value TG is set to a value lower than the upper limit value. In the example shown in FIG. 26( b), the carbon dioxide concentration in the vehicle cabin fluctuates within a range that is equal to or less than the upper limit value and equal to or greater than the target value TG from a predetermined time before arrival at the destination to the estimated arrival time t1. Ventilation is then performed so that the carbon dioxide concentration is within a range that is equal to or greater than threshold b and equal to or less than threshold f from a predetermined time before arrival at the destination to the estimated arrival time t1.

[0193] In this case, the quality of the passenger's behavior after getting off the vehicle can be improved in situations where the passenger wants to feel comfortable when arriving at their destination, such as when they are commuting to work or school and then working or studying after getting off the vehicle.

[0194] As described above, the target value is set based on the behavior of the occupants after the vehicle has arrived at the destination, so that the occupants can get off the vehicle in a comfortable mood.

[0195] [Advantages of the Present Embodiment] (a1) The vehicle air conditioner 1 is capable of ventilating the vehicle cabin, and includes a concentration detection sensor 14a as a concentration detection unit that detects the concentration of carbon dioxide in the vehicle cabin, and a control device 13 as a ventilation control unit that controls the ventilation of the vehicle cabin so that the concentration of carbon dioxide in the vehicle cabin falls within a range between a lower limit value and an upper limit value. Therefore, the concentration of carbon dioxide in the vehicle cabin can be kept within an appropriate range.

[0196] (a2) In the vehicle air conditioning device 1 of (a1) above, the control device 13 as the ventilation control unit calculates the rate of increase of the carbon dioxide concentration in the vehicle cabin based on the change in the carbon dioxide concentration after the occupants get on board, obtains the estimated arrival time required for the vehicle to arrive at the destination from the time the occupants get on board, sets a target value for the carbon dioxide concentration in the vehicle cabin when the vehicle arrives at the destination, sets the carbon dioxide concentration that changes when the carbon dioxide concentration in the vehicle cabin rises from a lower limit value and reaches the target value at the estimated arrival time based on the rate of increase as a threshold value, creates a ventilation permission area that specifies the allowable range of the carbon dioxide concentration in the vehicle cabin according to the vehicle traveling time so that the allowable range of the carbon dioxide concentration in the vehicle cabin changes from a range above the lower limit value and below an upper limit value to a range above the threshold value and below the upper limit value according to the vehicle traveling time, and controls the ventilation in the vehicle cabin so that the carbon dioxide concentration in the vehicle cabin from the time the occupants get on board until the vehicle arrives at the destination falls within the range specified by the ventilation permission area. Therefore, by keeping the carbon dioxide concentration in the vehicle cabin within an appropriate range and avoiding unnecessary ventilation, it is possible to reduce the introduction of more outside air than necessary and suppress increases in energy consumption.

[0197] (b1) A vehicle air conditioning device 1 capable of ventilating the interior of a vehicle, comprising a concentration detection sensor 14a as a concentration detection unit that detects the concentration of carbon dioxide in the vehicle cabin, and a control device 13 as a ventilation control unit that controls the ventilation of the vehicle cabin, wherein the control device 13 as the ventilation control unit calculates the rate of increase of the concentration of carbon dioxide in the vehicle cabin based on a change in the concentration of carbon dioxide after an occupant gets on board, obtains an estimated arrival time required for the vehicle to arrive at the destination from the time the occupant gets on board, sets a target value for the concentration of carbon dioxide in the vehicle cabin when the vehicle arrives at the destination, and transitions when the concentration of carbon dioxide in the vehicle cabin rises from a lower limit value based on the rate of increase and reaches the target value at the estimated arrival time. The system uses a carbon dioxide concentration as a threshold, creates a ventilation permission region that defines the allowable range of carbon dioxide concentration in the vehicle cabin according to the vehicle's driving time so that the allowable range of carbon dioxide concentration in the vehicle cabin changes from a range between a lower limit and an upper limit to a range between the threshold and an upper limit according to the vehicle's driving time, determines the number of ventilation cycles from the time the occupant boards the vehicle until the vehicle arrives at the destination based on a predetermined ventilation rate that is defined as the upper limit of the carbon dioxide concentration to be reduced when the vehicle cabin is ventilated, and controls ventilation in the vehicle cabin so that the carbon dioxide concentration in the vehicle cabin from the time the occupant boards the vehicle until the vehicle arrives at the destination falls within the range defined by the ventilation permission region. Thus, the carbon dioxide concentration can be kept within the allowable range with the minimum number of ventilation cycles necessary, thereby suppressing an increase in energy consumption.

[0198] (c1) A vehicle air conditioner 1 capable of ventilating the interior of a vehicle cabin, comprising a control device 13 as a ventilation control unit that controls ventilation within the vehicle cabin, wherein the control device 13 as the ventilation control unit predicts changes in outside air temperature along the travel route based on travel route information for the travel route from the vehicle's position when the occupant gets on board to the destination, and increases the ventilation volume when the outside air temperature approaches a target temperature within the vehicle cabin. Therefore, by increasing the ventilation when the outside air temperature approaches the target temperature within the vehicle cabin, the air conditioning load when ventilation is performed can be reduced, and an increase in energy consumption can be suppressed.

[0199] (c2) The vehicle air conditioning device 1 of (c1) above is provided with a concentration detection sensor 14a as a concentration detection unit that detects the concentration of carbon dioxide in the vehicle cabin, and the control device 13 as the ventilation control unit calculates the rate of increase of the carbon dioxide concentration in the vehicle cabin based on the change in the carbon dioxide concentration after the occupants get on board, obtains the estimated arrival time required for the vehicle to arrive at the destination from the time the occupants get on board, sets a target value for the carbon dioxide concentration in the vehicle cabin when the vehicle arrives at the destination, sets a threshold value for the carbon dioxide concentration when the carbon dioxide concentration in the vehicle cabin increases from a lower limit value based on the rate of increase and reaches the target value at the estimated arrival time, creates a ventilation permission area that specifies the allowable range of the carbon dioxide concentration in the vehicle cabin according to the vehicle traveling time so that the allowable range of the carbon dioxide concentration in the vehicle cabin changes from a range above the lower limit value and below an upper limit value to a range above the threshold value and below the upper limit value according to the vehicle traveling time, and controls the ventilation in the vehicle cabin so that the carbon dioxide concentration in the vehicle cabin from the time the occupants get on board until the vehicle arrives at the destination falls within the range specified by the ventilation permission area. Therefore, by keeping the carbon dioxide concentration in the vehicle cabin within an appropriate range and avoiding unnecessary ventilation, it is possible to reduce the introduction of more outside air than necessary and suppress increases in energy consumption.

[0200] (d1) A vehicle air conditioner 1 capable of ventilating the vehicle cabin includes a control device 13 as a ventilation control unit that controls the ventilation of the vehicle cabin. The control device 13 as the ventilation control unit changes the timing of ventilation of the vehicle cabin or the ventilation volume when ventilating the vehicle cabin in response to a cooling request from a battery, which is an on-board heat-generating device. This prevents a temporary high rotation speed request due to an increase in air conditioning load and a battery temperature control request occurring simultaneously, thereby suppressing an increase in power consumption throughout the vehicle. Furthermore, this prevents a high load on the compressor, thereby suppressing a reduction in mechanical life.

[0201] (d2) The vehicle air conditioning device 1 of (d1) above is provided with a concentration detection sensor 14a as a concentration detection unit that detects the concentration of carbon dioxide in the vehicle cabin, and the control device 13 as the ventilation control unit calculates the rate of increase of the carbon dioxide concentration in the vehicle cabin based on the change in the carbon dioxide concentration after the occupants get on board, obtains the estimated arrival time required for the vehicle to arrive at the destination from the time the occupants get on board, sets a target value for the carbon dioxide concentration in the vehicle cabin when the vehicle arrives at the destination, sets the carbon dioxide concentration that changes when the carbon dioxide concentration in the vehicle cabin rises from a lower limit value and reaches the target value at the estimated arrival time based on the rate of increase as a threshold value, creates a ventilation permission area that specifies the allowable range of the carbon dioxide concentration in the vehicle cabin according to the vehicle traveling time so that the allowable range of the carbon dioxide concentration in the vehicle cabin changes from a range above the lower limit value and below an upper limit value according to the vehicle traveling time, and controls the ventilation in the vehicle cabin so that the carbon dioxide concentration in the vehicle cabin from the time the occupants get on board until the vehicle arrives at the destination falls within the range specified by the ventilation permission area. Therefore, by keeping the carbon dioxide concentration in the vehicle cabin within an appropriate range and avoiding unnecessary ventilation, it is possible to reduce the introduction of more outside air than necessary and suppress increases in energy consumption.

[0202] (e1) A vehicle air conditioner 1 capable of ventilating the interior of a vehicle cabin includes a control device 13 as a ventilation control unit that controls ventilation within the vehicle cabin, and the control device 13 as the ventilation control unit changes the timing of ventilation within the vehicle cabin or the amount of ventilation when ventilating the vehicle cabin in sections where air quality deteriorates along the travel route from the vehicle's position when the occupants board to the destination, thereby preventing factors that may harm the health of the occupants from entering the cabin.

[0203] (e2) The vehicle air conditioning device 1 of (e1) above is provided with a concentration detection sensor 14a as a concentration detection unit that detects the concentration of carbon dioxide in the vehicle cabin, and the control device 13 as the ventilation control unit calculates the rate of increase of the carbon dioxide concentration in the vehicle cabin based on the change in the carbon dioxide concentration after the occupants get on board, obtains the estimated arrival time required for the vehicle to arrive at the destination from the time the occupants get on board, sets a target value for the carbon dioxide concentration in the vehicle cabin when the vehicle arrives at the destination, sets a threshold value for the carbon dioxide concentration when the carbon dioxide concentration in the vehicle cabin increases from a lower limit value based on the rate of increase and reaches the target value at the estimated arrival time, creates a ventilation permission area that specifies the allowable range of the carbon dioxide concentration in the vehicle cabin according to the vehicle traveling time so that the allowable range of the carbon dioxide concentration in the vehicle cabin changes from a range above the lower limit value and below an upper limit value according to the vehicle traveling time, and controls the ventilation in the vehicle cabin so that the carbon dioxide concentration in the vehicle cabin from the time the occupants get on board until the vehicle arrives at the destination falls within the range specified by the ventilation permission area. Therefore, by keeping the carbon dioxide concentration in the vehicle cabin within an appropriate range and avoiding unnecessary ventilation, it is possible to reduce the introduction of more outside air than necessary and suppress increases in energy consumption.

[0204] (e3) In the vehicle air conditioner 1 described in (e1) above, the control device 13 as the ventilation control unit can output suggestion information to the occupant that suggests a driving route that will not deteriorate the air quality. Therefore, the occupant can set the route as desired to prevent factors that may harm the occupant's health from entering the cabin.

[0205] (f1) A vehicle air conditioner 1 capable of ventilating the interior of a vehicle compartment, comprising: a concentration detection sensor 14a as a concentration detection unit that detects the concentration of carbon dioxide in the vehicle compartment; a weight sensor 14e as an occupant number change information output unit that outputs information on a change in the number of occupants in the vehicle compartment; and a control device 13 as a ventilation control unit that controls ventilation of the vehicle compartment, wherein the control device 13 as the ventilation control unit calculates a rate of increase in the concentration of carbon dioxide in the vehicle compartment based on a change in the concentration of carbon dioxide after the occupants get on board, obtains an estimated arrival time required for the vehicle to arrive at the destination from the time the occupants get on board, sets a target value for the concentration of carbon dioxide in the vehicle compartment when the vehicle arrives at the destination, and calculates the rate of increase. The system sets a threshold value to the carbon dioxide concentration that changes when the carbon dioxide concentration in the vehicle cabin increases from a lower limit value based on the above and reaches a target value at the estimated arrival time, creates a ventilation permission area that specifies the allowable range of the carbon dioxide concentration in the vehicle cabin depending on the vehicle traveling time so that the allowable range of the carbon dioxide concentration in the vehicle cabin changes from a range equal to or greater than the lower limit value and equal to or less than the upper limit value to a range equal to or greater than the threshold value and equal to or less than the upper limit value depending on the vehicle traveling time, recreates the ventilation permission area when information on a change in the number of occupants in the vehicle cabin is input, and controls ventilation in the vehicle cabin so that the carbon dioxide concentration in the vehicle cabin from the time occupants get on board until the vehicle arrives at the destination falls within the range specified by the ventilation permission area. Thus, ventilation can be performed at the optimal timing even if the number of occupants in the vehicle cabin increases or decreases, thereby reducing unnecessary ventilation.

[0206] (g1) A vehicle air conditioner 1 capable of ventilating the vehicle cabin includes an outside air temperature sensor 14c as an outside air temperature detection unit that detects the outside air temperature, an inside air temperature sensor 14b as an inside air temperature detection unit that measures the temperature of the air inside the vehicle cabin, and a control device 13 as a ventilation control unit that controls ventilation inside the vehicle cabin. The control device 13 as the ventilation control unit ventilates the vehicle cabin when the outside air temperature is closer to a target temperature inside the vehicle cabin than the temperature inside the vehicle cabin. This prevents ventilation from being performed immediately after the temperature inside the vehicle cabin reaches the target temperature. This prevents the temperature inside the vehicle cabin from deviating from the target temperature immediately after reaching the target temperature, resulting in a decrease in comfort. Furthermore, by replacing the air inside the vehicle cabin with outside air during start-up operation, the air conditioning load during start-up operation can be reduced when the outside air temperature is closer to the target temperature inside the vehicle cabin than the temperature inside the vehicle cabin. Furthermore, the number and volume of ventilation operations performed after start-up operation can be reduced, thereby suppressing an increase in energy consumption.

[0207] (g2) The vehicle air conditioning device 1 of (g1) above is provided with a concentration detection sensor 14a as a concentration detection unit that detects the concentration of carbon dioxide in the vehicle cabin, and the control device 13 as the ventilation control unit calculates the rate of increase of the carbon dioxide concentration in the vehicle cabin based on the change in the carbon dioxide concentration after the occupants get on board, obtains the estimated arrival time required for the vehicle to arrive at the destination from the time the occupants get on board, sets a target value for the carbon dioxide concentration in the vehicle cabin when the vehicle arrives at the destination, sets a threshold value for the carbon dioxide concentration when the carbon dioxide concentration in the vehicle cabin increases from a lower limit value based on the rate of increase and reaches the target value at the estimated arrival time, creates a ventilation permission area that specifies the allowable range of the carbon dioxide concentration in the vehicle cabin according to the vehicle traveling time so that the allowable range of the carbon dioxide concentration in the vehicle cabin changes from a range above the lower limit value and below an upper limit value according to the vehicle traveling time, and controls the ventilation in the vehicle cabin so that the carbon dioxide concentration in the vehicle cabin from the time the occupants get on board until the vehicle arrives at the destination falls within the range specified by the ventilation permission area. Therefore, by keeping the carbon dioxide concentration in the vehicle cabin within an appropriate range and avoiding unnecessary ventilation, it is possible to reduce the introduction of more outside air than necessary and suppress increases in energy consumption.

[0208] (h1) A vehicle air conditioner 1 capable of ventilating the interior of a vehicle cabin, comprising an outside air temperature sensor 14c as an outside air temperature detection unit that detects the outside air temperature, an inside air temperature sensor 14b as an inside air temperature detection unit that measures the temperature of the air inside the cabin, and a control device 13 as a ventilation control unit that controls the ventilation inside the cabin, wherein the control device 13 as the ventilation control unit adjusts the ventilation volume when ventilating the interior of the vehicle cabin or the ventilation time when ventilating the interior of the vehicle cabin based on the target temperature inside the vehicle cabin, the outside air temperature, and the temperature inside the vehicle cabin. Thus, a ventilation plan is created after determining the ventilation time and ventilation volume within a range that does not affect the comfort of the occupants, thereby preventing a deterioration in comfort for the occupants.

[0209] (h2) The vehicle air conditioning device 1 of (h1) above is provided with a concentration detection sensor 14a as a concentration detection unit that detects the concentration of carbon dioxide in the vehicle cabin, and the control device 13 as the ventilation control unit calculates the rate of increase of the carbon dioxide concentration in the vehicle cabin based on the change in the carbon dioxide concentration after the occupants get on board, obtains the estimated arrival time required for the vehicle to arrive at the destination from the time the occupants get on board, sets a target value for the carbon dioxide concentration in the vehicle cabin when the vehicle arrives at the destination, sets the carbon dioxide concentration that changes when the carbon dioxide concentration in the vehicle cabin rises from a lower limit value and reaches the target value at the estimated arrival time based on the rate of increase as a threshold value, creates a ventilation permission area that specifies the allowable range of the carbon dioxide concentration in the vehicle cabin according to the vehicle traveling time so that the allowable range of the carbon dioxide concentration in the vehicle cabin changes from a range above the lower limit value and below an upper limit value according to the vehicle traveling time, and controls the ventilation in the vehicle cabin so that the carbon dioxide concentration in the vehicle cabin from the time the occupants get on board until the vehicle arrives at the destination falls within the range specified by the ventilation permission area. Therefore, by keeping the carbon dioxide concentration in the vehicle cabin within an appropriate range and avoiding unnecessary ventilation, it is possible to reduce the introduction of more outside air than necessary and suppress increases in energy consumption.

[0210] (i1) A vehicle air conditioner 1 capable of ventilating the vehicle cabin includes a control device 13 as a ventilation control unit that controls the ventilation of the vehicle cabin. The control device 13 as the ventilation control unit pre-cools or pre-heats the air in the vehicle cabin depending on the timing of ventilation of the vehicle cabin. As a result, the temperature difference between the temperature in the vehicle cabin and the target temperature is kept within a predetermined range, thereby extending the ventilation time while suppressing discomfort to the occupants. Furthermore, since the ventilation volume can be secured, the ventilation frequency can be reduced, thereby suppressing the load on the compressor, etc.

[0211] (i2) In the vehicle air conditioning device 1 of (i1) above, the control device 13 as the ventilation control unit calculates the rate of increase of the carbon dioxide concentration in the vehicle cabin based on the change in the carbon dioxide concentration after the occupants get on board, obtains the estimated arrival time required for the vehicle to arrive at the destination from the time the occupants get on board, sets a target value for the carbon dioxide concentration in the vehicle cabin when the vehicle arrives at the destination, sets a threshold value for the carbon dioxide concentration when the carbon dioxide concentration in the vehicle cabin rises from a lower limit value based on the rate of increase and reaches the target value at the estimated arrival time, creates a ventilation permission area that specifies the allowable range of the carbon dioxide concentration in the vehicle cabin according to the vehicle traveling time so that the allowable range of the carbon dioxide concentration in the vehicle cabin changes from a range above the lower limit value and below an upper limit value to a range above the threshold value and below the upper limit value according to the vehicle traveling time, and controls the ventilation in the vehicle cabin so that the carbon dioxide concentration in the vehicle cabin from the time the occupants get on board until the vehicle arrives at the destination falls within the range specified by the ventilation permission area. Therefore, by keeping the carbon dioxide concentration in the vehicle cabin within an appropriate range and avoiding unnecessary ventilation, it is possible to reduce the introduction of more outside air than necessary and suppress increases in energy consumption.

[0212] (j1) A vehicle air conditioner 1 capable of ventilating the interior of a vehicle, comprising a concentration detection sensor 14a as a concentration detection unit that detects the concentration of carbon dioxide in the vehicle interior, and a control device 13 as a ventilation control unit that controls the ventilation of the vehicle interior, wherein the control device 13 as the ventilation control unit calculates the rate of increase in the concentration of carbon dioxide in the vehicle interior based on a change in the concentration of carbon dioxide after an occupant gets on board, obtains an estimated arrival time required for the vehicle to arrive at its destination from the time the occupant gets on board, predicts the behavior of the occupant after the vehicle arrives at its destination, and calculates the concentration of carbon dioxide in the vehicle interior when the vehicle arrives at its destination based on the predicted result. a target value for the concentration of carbon dioxide in the vehicle cabin is set, the concentration of carbon dioxide that changes when the concentration of carbon dioxide in the vehicle cabin rises from a lower limit value based on the rate of increase and reaches the target value at the estimated arrival time is set as a threshold value, a ventilation permission area is created that defines the allowable range of the concentration of carbon dioxide in the vehicle cabin according to the traveling time of the vehicle so that the allowable range of the concentration of carbon dioxide in the vehicle cabin changes from a range equal to or greater than the lower limit value and equal to or less than the upper limit value to a range equal to or greater than the threshold value and equal to or less than the upper limit value according to the traveling time of the vehicle, and ventilation in the vehicle cabin is controlled so that the concentration of carbon dioxide in the vehicle cabin from the time the occupant gets on board until the vehicle arrives at the destination falls within the range defined by the ventilation permission area. Thus, the target value is set based on the behavior of the occupant after the vehicle arrives at the destination, allowing the occupant to exit the vehicle in a comfortable mood.

[0213] The present invention has been described above by showing preferred embodiments, but it goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention.

[0214] 1: Vehicle air conditioning device 10: Heat medium circuit 11: Refrigerant circuit 12: HVAC unit 13: Control device 13a: Carbon dioxide increase rate calculation unit 13b: Estimated arrival time acquisition unit 13c: Target value setting unit 13d: Threshold value setting unit 13e: Ventilation permission area creation unit 14: Sensor 14a: Concentration detection sensor 14b: Inside air temperature sensor 14c: Outside air temperature sensor 14d: Air outlet temperature sensor 14e: Weight sensor 15: Operation unit 16: Display unit 17: Speaker 18: Communication bus 19: Power window device 20: Navigation device

Claims

1. A vehicle air conditioner capable of ventilating a vehicle cabin, comprising: a concentration detection unit that detects the concentration of carbon dioxide in the vehicle cabin; and a ventilation control unit that controls ventilation in the vehicle cabin so that the concentration of carbon dioxide in the vehicle cabin falls within a range between a lower limit value and an upper limit value.

2. The vehicle air conditioning device according to claim 1, characterized in that the ventilation control unit: calculates a rate of increase in the carbon dioxide concentration in the vehicle cabin based on a change in the carbon dioxide concentration after the occupant gets on board; obtains an estimated arrival time required for the vehicle to arrive at the destination from the time the occupant gets on board; sets a target value for the carbon dioxide concentration in the vehicle cabin when the vehicle arrives at the destination; sets a threshold value for the carbon dioxide concentration at which the carbon dioxide concentration in the vehicle cabin rises from a lower limit value and reaches the target value at the estimated arrival time based on the rate of increase; creates a ventilation permission area that specifies the acceptable range of the carbon dioxide concentration in the vehicle cabin according to the vehicle driving time so that the acceptable range of the carbon dioxide concentration in the vehicle cabin changes from a range between the lower limit value and the upper limit value to a range between the threshold value and the upper limit value according to the vehicle driving time; and controls the ventilation in the vehicle cabin so that the carbon dioxide concentration in the vehicle cabin from the time the occupant gets on board until the vehicle arrives at the destination falls within the range specified in the ventilation permission area.

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