JP3740758B2 - Air conditioner for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle air conditioner that detects the degree of air pollution outside a passenger compartment with a gas sensor and forcibly changes from the outside air introduction mode to the inside air circulation mode when the detection value of the gas sensor rises above a set value. It is about.
[0002]
[Prior art]
As a conventional technology, an automatic inside / outside air system that detects the degree of air pollution outside the passenger compartment with a gas sensor and forcibly changes the outside air introduction mode to the inside air circulation mode when the detected value of the gas sensor rises above a set value. There is. In this known auto inside / outside air system, the judgment level of the detection value of the gas sensor is always constant.
[0003]
Conventionally, in Japanese Patent Application Laid-Open No. 59-8518, the inside / outside air switching door is connected to the inside air according to the time required for the gas concentration contained in the air outside the passenger compartment detected by the gas sensor to rise above a predetermined value. An automatic air conditioner is described in which contaminated air is prevented from entering the passenger compartment by forcibly switching to the circulation mode.
[0004]
[Problems to be solved by the invention]
However, in the above-described two conventional technologies, the inside air circulation mode is maintained for many hours when traveling in an urban area with a high degree of pollution. For this reason, there is a problem that the occupant's mood deteriorates due to an increase in the CO ₂ concentration in the passenger compartment or a slight intrusion of NOx, or the window glass becomes clouded due to an increase in humidity due to the occupant's breathing. In order to prevent these problems, if various sensors such as a gas sensor for detecting the degree of contamination in the passenger compartment are provided, the product price is greatly increased.
[0005]
In recent years, the number of users who prefer the inside air circulation mode among the suction port modes has increased, and automatic inside / outside air control with a high proportion of the inside air circulation mode is required. However, if the predetermined value of the detection value of the gas sensor is lowered using the conventional technique, it is conceivable that the inside air circulation mode continues for a longer time. Therefore, there arises a problem that the above-described problems are further increased.
[0006]
OBJECT OF THE INVENTION
An object of the present invention is to provide a vehicle air conditioner that can prevent deterioration of passengers' feelings and prevent fogging from occurring on the window glass by preventing the internal air circulation mode from being maintained for a long time. There is to do.
[0007]
[Means for Solving the Problems]
According to the first aspect of the present invention, when the detected value related to the degree of pollution of the air outside the vehicle compartment detected by the pollution degree detection means rises above the set value, the inside / outside air control means switches to the inside air circulation mode. The inside / outside air switching means is controlled to hold. As a result, the inside air inlet of the duct is opened and the outside air inlet is closed, so that the air in the passenger compartment circulates through the duct.
[0008]
And the suction port mode is held in the inside air circulation mode by setting the set value for performing comparison with the detection value of the contamination degree detection means to a high level higher than the standard value for a predetermined inside air holding time. The Then, after a predetermined inside air holding time has elapsed, the set value is returned to the standard value for a predetermined ventilation permission time. Thereafter, the Rukoto continuously or stepwise decreased over the set value time, even if the vehicle exterior air is slightly contaminated, if after a certain period of time, the detection value of the contamination degree detection means set value To rise more. When the detected value of such contamination degree detection means rises above the set value, outside air switching means is controlled to switch so that the outside air introduction mode from the inside air circulation mode by the inner and outer air control means. As a result, the inside air inlet of the duct is closed and the outside air inlet is opened, so that air outside the passenger compartment is introduced into the passenger compartment through the duct and ventilated. As a result, it is possible to suppress deterioration of the occupant's mood due to an increase in the carbon dioxide concentration in the air in the passenger compartment due to being kept in the inside air circulation mode for a long time, and a window due to an increase in the humidity in the passenger compartment. The occurrence of fogging of the glass can be suppressed.
[0009]
According to the second aspect of the present invention, the set value is set to a constant value during the inside air holding time in which the suction port mode is held in the inside air circulation mode, so that polluted air outside the passenger compartment is passed through the duct. Intruding into the passenger compartment. Thereby, it is possible to suppress the deterioration of the occupant's mood due to an increase in the degree of air pollution in the passenger compartment.
[0010]
According to the third aspect of the present invention, the larger the number of passengers, the shorter the inside air holding time in which the suction port mode is held in the inside air circulation mode (the inside air holding time for keeping the set value at a constant value). By changing, the inside air circulation mode can be maintained for a long time when the number of passengers is small, and the outside air introduction mode can be changed in a short time when the number of passengers is large.
According to the fourth aspect of the present invention, the amount of decrease in which the set value is decreased continuously or stepwise is changed so as to increase as the number of occupants increases. It can be held for a long time and can be changed to the outside air introduction mode in a short time when the number of passengers is large.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
[Configuration of First Embodiment]
1 to 6 show a first embodiment of the present invention, and FIG. 1 shows a vehicle air conditioner.
[0012]
The vehicle air conditioner 1 has a duct 2 installed on the front side of the vehicle interior of the vehicle. Inside the duct 2, an inside / outside air switching door 3, a blower 4, an evaporator 5, from upstream to downstream. Air heating means such as two air mix doors 6 and a heater core 7 and two air outlet switching doors 8 are provided.
[0013]
The inside / outside air switching door 3 is an inside / outside air switching means that is driven by door driving means such as the servo motor 11 and switches the suction port mode. The inside / outside air switching door 3 includes an inside air circulation mode for sucking air in the vehicle interior (hereinafter referred to as inside air) from an inside air suction port 21 formed on the most upstream side of the duct 2 and air outside the vehicle compartment from the outside air suction port 22 (hereinafter referred to as air inside the vehicle interior). Switch to the outside air introduction mode for sucking in outside air).
[0014]
The blower 4 is a blower that generates an air flow toward the vehicle interior in the duct 2 in accordance with the rotational speed of the blower motor 15 whose applied voltage (hereinafter referred to as blower voltage) is controlled by a blower controller (blower drive circuit) 14. .
The evaporator 5 is a refrigerant evaporator of a so-called refrigeration cycle, and is an air cooling means that cools the air sent by the blower 4 by heat exchange with the refrigerant according to the operation of the compressor. The two air mix doors 6 are driven by a servo motor 12 and adjust the amount of air passing through the heater core 7 and the amount of air bypassing the heater core 7 according to the opening degree. The heater core 7 is an air heating means that heats the air passing therethrough with cooling water that cools the engine of the vehicle. The evaporator 5, the two air mix doors 6 and the heater core 7 constitute a blowing temperature adjusting means.
[0015]
The two air outlet switching doors 8 are air outlet switching means that is driven by the servo motor 13 and switches the air outlet mode. These air outlet switching doors 8 open and close the face air outlet 23, the defroster air outlet 24, and the foot air outlet 25 formed on the most downstream side of the duct 2 to change the air outlet mode to the face mode, the bi-level mode, and the foot. Switch to mode, foot differential mode or defroster mode.
[0016]
The servo motors 11 to 13 and the blower controller 14 are controlled based on a control signal from the air conditioning control device 10 such as a microcomputer. The air conditioning control device 10 is an inside / outside air control means of the present invention, and is an air conditioning control means including a central processing unit CPU, a read only memory ROM, a random access memory RAM and the like, and is well known per se. The air-conditioning control device 10 includes an inside air temperature detecting means such as an inside air temperature sensor 31 that detects an air temperature (inside air temperature) inside the vehicle interior, and an outside air temperature sensor 32 that detects the air temperature outside the vehicle compartment (outside air temperature). Temperature detection means, solar radiation amount detection means such as a solar radiation sensor 33 that detects the amount of solar radiation entering the vehicle interior, post-evaporation temperature detection means such as a post-evaporation temperature sensor 34 that detects the temperature of air that has passed through the evaporator 5 (post-evaporation temperature) Cooling water temperature detecting means (not shown) such as a cooling water temperature sensor for detecting the cooling water temperature of the engine, temperature setting means such as a temperature setting switch 36 provided in the air conditioning operation panel 35, and contamination level detection of the exhaust gas sensor 9 and the like Means are connected. The exhaust gas sensor 9 detects the degree of pollution outside the passenger compartment from the concentration of harmful gas such as carbon monoxide (CO) in the air, and outputs an electrical signal (for example, a voltage signal) corresponding to the detected value.
[0017]
[Operation of air conditioning control device]
Next, operation | movement of the air-conditioning control apparatus 10 of this embodiment is demonstrated easily based on FIG. 1 thru | or FIG. Here, FIG. 2 is a flowchart showing an example of the operation of the air conditioning control device.
[0018]
First, the contents stored in a random access memory (data processing memory) are initialized (step S1). Next, the outside air timer counter (ventilation permission time) FRS is set to an initial set value (for example, 1 to 30 minutes) sufficient to ventilate the vehicle interior calculated from the steady blower voltage, and the inside air timer counter REC (inside air holding time). An initial set value (for example, 10 minutes to 30 minutes) calculated from the number of passengers is substituted, and a pollution degree determination level (set value) Vset, which is a determination value of the degree of pollution outside the passenger compartment detected by the gas sensor 9, is set sufficiently high ( Step S2). As a method for detecting the number of occupants, the number of occupants may be determined by the number of opening and closing of the doors of the vehicle, or the number of occupants may be detected by a radiation thermometer or the like.
[0019]
Random access memory by reading the set temperature Tset set by the temperature setting switch 36 of the air conditioning operation panel 35, the internal air temperature Tr detected by each sensor, the external air temperature Tam, the solar radiation amount Ts, the post-evacuation temperature Te, the cooling water temperature Tw, etc. (Step S3).
Next, based on the set temperature Tset, the inside air temperature Tr, the outside air temperature Tam, and the solar radiation amount Ts, the target value of the air blown out from the duct 2 through each air outlet into the vehicle interior, that is, the target air outlet temperature TAO is expressed by the following number. 1 is obtained by an equation (step S4).
[Expression 1]
TAO = Kset, Tset-Kr, Tr-Kam, Tam-Ks, Ts + C
However, Kset, Kr, Kam, Ks represents a correction gain, and C represents a correction constant.
[0020]
Next, suction port mode determination control is performed based on the flowchart shown in FIG. 3 (step S5). Next, a control output is output to the servomotor 11 so as to be in the suction port mode set in step S5 (air conditioning control means: step S6), and based on the characteristic diagram shown in FIG. (Step S7), and based on the characteristic diagram shown in FIG. 5, the outlet mode is determined according to the target outlet temperature TAO (step S8).
[0021]
Next, based on the target blowing temperature TAO, the post-evaporation temperature Te, and the cooling water temperature Tw, the target door opening degree SW (%) of the air mix door 6 is obtained by the following formula 2 (step S9).
[Expression 2]
SW (%) = (TAO−Te) / (Tw−Te) × 100
[0022]
After each control output value is determined, a control output is output to the blower controller 14 so that the blower voltage determined in step S6 is obtained (step S10), and the target door opening SW obtained in step S9 is set. Thus, a control output is output to the servo motor 12 (step S11), and a control output is output to the servo motor 13 so as to be in the air outlet mode determined in step S6 (step S12). Next, the process returns to step S3.
[0023]
Next, the suction port mode setting control of the air conditioning control device 10 of the present embodiment will be briefly described with reference to FIGS. 1 to 3. Here, FIG. 3 is a subroutine showing the suction port mode determination control.
[0024]
In step S5 of FIG. 2, it is first determined whether or not the inside air timer counter REC is “0”. That is, it is determined whether or not (REC = 0) (inside air retention time determination means: step S21). If the determination result is NO, (REC ← REC-1) is performed. That is, “1” is subtracted from the value of the inside air timer counter REC (step S22). Next, it is determined whether or not the inside air timer counter REC is “0”. That is, it is determined whether or not (REC = 0) (inside air retention time determination means: step S23).
[0025]
If the determination result in this step S23 is NO, the pollution degree determination level Vset remains “high” and the suction port mode is continuously set to the inside air circulation mode (suction port mode setting means: step S24).
If the determination result in step S23 is YES, it is determined that the inside air retention time has ended, and the contamination degree determination level Vset is changed from “high” to “standard value” (= CO concentration is 10 ppm) ( Step S25). Next, the process proceeds to step S24, and the suction port mode is continued and the inside air circulation mode is set.
[0026]
If the determination result in step S21 is YES, it is determined that the inside air holding time has ended, and the auto inside / outside air mode is entered. Then, it is determined whether or not the outside air timer counter FRS is “0”. That is, it is determined whether or not (FRS = 0) (ventilation permission time determination means: step S26).
If the determination result in step S26 is NO, it is determined that the ventilation permission time has not ended, and it is determined whether or not the mode may be changed to the outside air introduction mode. That is, it is determined whether or not the output voltage (detected value of the exhaust gas sensor 9) Vg corresponding to the degree of contamination outside the vehicle compartment (CO concentration) detected by the exhaust gas sensor 9 is higher than the contamination level determination level (set value) Vset. (Contamination degree determination means: step S27).
[0027]
If the decision result in the step S27 is YES, (Vset ← Vset−ΔV) is performed. That is, “1” is subtracted from the value of the contamination degree determination level Vset (set value reduction means: step S28). Next, (FRS ← FRS-1) is performed. That is, “1” is subtracted from the value of the outside air timer counter FRS (step S29). Next, the suction port mode is set to the outside air introduction mode (suction port mode setting means: step S30).
If the determination result in step S27 is NO, it is determined that the air outside the passenger compartment (outside air) is somewhat contaminated, and (Vset ← Vset−ΔV) is performed. That is, “1” is subtracted from the value of the contamination degree determination level Vset (set value reduction means: step S31). Next, the suction port mode is set to the inside air circulation mode (suction port mode setting means: step S32).
[0028]
Moreover, when the determination result of step S26 is YES, it determines with the ventilation permission time having been complete | finished, and complete | finishes auto inside / outside air mode. Then, the contamination degree determination level (set value) Vset is set sufficiently high, and the initial set values are substituted into the outside air timer counter (ventilation permission time) FRS and the inside air timer counter REC (inside air holding time) (step S33). Next, the suction port mode is set to the inside air circulation mode (suction port mode setting means: step S34).
[0029]
[Operation of First Embodiment]
Next, the operation of the vehicle air conditioner 1 according to the present embodiment will be briefly described with reference to FIGS. Here, FIG. 6 is a time chart showing the suction port mode, the waveform of the output voltage of the exhaust gas sensor, and the waveform of the contamination degree determination level.
[0030]
In the suction port mode determination control of the present embodiment, the suction port mode is set to the inside air circulation mode until the inside air holding time elapses. Thereby, the inside air sucked from the inside air suction port 21 is blown out into the vehicle compartment via the duct 2. When time A shown in FIG. 6 is reached, that is, when the inside air retention time has elapsed, the contamination level determination level Vset is changed from “high” to “standard value” (= CO concentration is 10 ppm). Then, counting of the outside air timer counter FRS is started from time A, and the contamination degree determination level Vset is gradually decreased gradually. Note that the amount of decrease ΔV per unit time of the contamination degree determination level Vset is set to a value at which the value of the contamination degree determination level Vset decreases from, for example, 10 ppm to 5 ppm in 30 minutes.
[0031]
When the time B shown in FIG. 6 is reached, the output voltage Vg corresponding to the degree of pollution outside the passenger compartment detected by the exhaust gas sensor 9 rises above the pollution degree judgment level Vset, so that the inlet mode is the outside air introduction mode. Can be switched to. As a result, the outside air sucked from the outside air inlet 22 is blown out into the passenger compartment through the duct 2, so that the air is forcibly ventilated even if the outside air is somewhat dirty. When the time C shown in FIG. 6 is reached, that is, when the ventilation permission time has elapsed, the pollution level determination level Vset is changed to “high”, so that the output voltage g of the exhaust gas sensor 9 becomes the pollution level determination level. Since it falls below Vset, the suction port mode is switched to the inside air circulation mode. Thereby, since the inside air sucked in from the inside air suction port 21 is blown out into the vehicle interior via the duct 2, contamination of the vehicle interior due to the intake of contaminated outside air can be prevented.
[0032]
Then, the count of the inside air timer counter RES is started from time C, and the contamination degree determination level Vset is “high” (constant) from time C to time D shown in FIG. 6, that is, until the inside air holding time elapses. Value). When the time D shown in FIG. 6 is reached, that is, when the inside air retention time has elapsed, the contamination degree determination level Vset is changed from “high” to “standard value” again. Then, counting of the outside air timer counter FRS is started from time D, and the contamination degree determination level Vset is gradually and gradually lowered.
[0033]
When the time E shown in FIG. 6 is reached, the output voltage Vg corresponding to the degree of pollution outside the passenger compartment detected by the exhaust gas sensor 9 rises above the pollution degree determination level Vset, so that the inlet mode is the outside air introduction mode. Can be switched to. As a result, the outside air sucked from the outside air inlet 22 is blown out into the passenger compartment through the duct 2, so that the air is forcibly ventilated even if the outside air is somewhat dirty. Then, when the time F shown in FIG. 6 is reached, the output voltage g of the exhaust gas sensor 9 decreases below the contamination level determination level Vset, so that the suction port mode is switched to the inside air circulation mode again. Thereby, the inside air sucked from the inside air suction port 21 is blown out into the vehicle compartment via the duct 2.
[0034]
When the time G shown in FIG. 6 is reached, the output voltage Vg corresponding to the degree of pollution outside the passenger compartment detected by the exhaust gas sensor 9 rises above the pollution degree judgment level Vset, so that the inlet mode is the outside air introduction mode. Can be switched to. As a result, the outside air sucked from the outside air inlet 22 is blown out into the vehicle compartment via the duct 2. When the time H shown in FIG. 6 is reached, that is, when the ventilation permission time has elapsed, the pollution level determination level Vset is changed to “high”, so that the output voltage g of the exhaust gas sensor 9 becomes the pollution level determination level. Since it falls below Vset, the suction port mode is switched to the inside air circulation mode again. Thereafter, the above operation is repeated.
[0035]
[Effects of First Embodiment]
As described above, in this embodiment, in addition to the exhaust gas sensor 9 attached outside the vehicle compartment, a pollution degree sensor such as a CO ₂ sensor that detects the degree of pollution in the vehicle interior and a humidity sensor that detects humidity in the vehicle interior are provided. Since it is possible to provide an auto inside / outside air system centering on the inside air circulation mode without being installed in the passenger compartment, the product price can be reduced by reducing the number of parts. And since the inlet mode is centered on the inside air circulation mode, it is possible to prevent the passenger compartment from being deteriorated by introducing contaminated outside air into the passenger compartment even when traveling in a highly polluted city area, thereby preventing the passengers from feeling worse. .
[0036]
Further, after the inside air retention time has elapsed, until the elapse of the ventilation permission time, by gradually lowering the contamination determination level Vset continuously be somewhat outside air pollution, ventilation permitted If the output voltage g of the exhaust gas sensor 9 rises above the contamination degree determination level Vset during the time, ventilation is forcibly performed. As a result, ventilation is performed even when traveling in a highly polluted city area, so that the CO ₂ concentration in the passenger compartment increases due to the suction mode being fixed for a long time in the inside air circulation mode, or a slight NOx intrusion occurs. It is possible to prevent the occupant's mood from deteriorating due to, for example, accumulation, and to prevent fogging of the window glass such as the front window glass due to an increase in humidity in the passenger compartment due to breathing.
[0037]
[Second Embodiment]
FIGS. 7 and 8 show a second embodiment of the present invention, and FIGS. 7 and 8 are time charts showing waveforms of contamination degree determination levels.
[0038]
In this embodiment, the inside air holding time for maintaining the contamination degree determination level Vset at a constant value (“high”) is changed according to the number of passengers riding on the vehicle. For example, when only one person is in the passenger compartment, as shown in FIG. 7, the amount of increase in CO ₂ and humidity per unit time is small, so only REC for a long time (= inside air holding time, for example, 30 minutes). The inlet mode is fixed to the inside air circulation mode.
[0039]
In addition, when four people are in the passenger compartment, the amount of increase in CO ₂ and humidity per unit time is large, so as shown in FIG. 8, the REC is short (= inside air holding time, for example, 10 minutes). Only fix the inlet mode to the inside air circulation mode. Similarly, when the number of occupants in the passenger compartment is 2, 3, 5 or more, the larger the number of occupants, the more the inside air that keeps the pollution level determination level Vset at a constant value (“high”). Set the retention time short . Here, as a method of detecting the number of occupants, the number of occupants may be determined by the number of opening / closing of the doors of the vehicle, or the number of occupants may be detected by a radiation thermometer or the like.
[0040]
[Third Embodiment]
FIGS. 9 to 10 show a third embodiment of the present invention, and FIGS. 9 and 10 are time charts showing waveforms of contamination degree determination levels.
[0041]
In the present embodiment, in the ventilation permitted time FRS, the decrease amount ΔV per unit degree of contamination determination level Vset time, so that to change the number of passengers riding on the vehicle. For example, when only one person is in the passenger compartment, the decrease amount ΔV per unit time is reduced as shown in FIG. 9 so as to continue the inside air circulation mode for a long time. Further, when four people are in the passenger compartment, the decrease amount ΔV per unit time is set so as to switch to the outside air introduction mode in a short time, that is, to perform forced ventilation, as shown in FIG. Enlarge. Similarly, when the number of occupants in the passenger compartment is 2, 3, 5 or more, the larger the number of occupants, the larger the reduction amount ΔV per unit time of the pollution degree determination level Vset is set. To do.
[0042]
[Fourth Embodiment]
FIG. 11 shows the fourth embodiment of the present invention, and FIG. 11 is a graph showing the relationship between the ventilation permission time and the blower voltage.
[0043]
In this embodiment, when the suction port mode is the outside air introduction mode, the amount of outside air introduced into the vehicle interior, the so-called ventilation amount, is substantially proportional to the amount of air blown by the blower 4. The optimum ventilation permission time can be set by correcting the length of the ventilation permission time according to the speed or the blower voltage.
[0044]
Other Embodiment
In each embodiment, the exhaust gas sensor 9 that detects the concentration of harmful gas such as CO in the air is used as the pollution degree detection means. However, the exhaust gas that detects the concentration of harmful gas such as nitrogen oxide (NOx) in the air is used. A contamination degree detection means such as a gas sensor, a harmful gas sensor, or a gas sensor may be used.
[0045]
In each embodiment, during the contamination determination level (setpoint) Vset as the determination value when switching air inlet mode from the inside air circulation mode to an outside air introduction mode ventilated allowed time continuously and gradually reduced, contamination level determination level (setpoint) Vset may be stepwise reduced in the ventilation permitted time.
[0046]
In the second embodiment, the larger the number of passengers, the shorter the inside air retention time for maintaining the pollution degree determination level Vset at a constant value. However, the smaller the volume in the vehicle interior, the lower the pollution degree determination level. The inside air holding time for keeping Vset at a constant value may be set short .
[0047]
In the third embodiment, the decrease amount ΔV per unit time of the pollution degree determination level Vset is set to be larger as the number of occupants is larger. However, the smaller the vehicle interior volume is, the smaller the unit of the pollution degree determination level Vset is. The decrease amount ΔV per time may be set large.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a vehicle air conditioner (first embodiment).
FIG. 2 is a flowchart showing an example of the operation of the air conditioning control device (first embodiment).
FIG. 3 is a subroutine showing suction port mode determination control (first embodiment).
FIG. 4 is a characteristic diagram showing a blower voltage based on a target blowing temperature (first embodiment).
FIG. 5 is a characteristic diagram showing an outlet mode based on a target outlet temperature (first embodiment).
FIG. 6 is a time chart showing a suction port mode, a waveform of an output voltage of an exhaust gas sensor, and a waveform of a contamination degree determination level (first embodiment).
FIG. 7 is a time chart showing a waveform of a contamination degree determination level (second embodiment).
FIG. 8 is a time chart showing a waveform of a contamination degree determination level (second embodiment).
FIG. 9 is a time chart showing a waveform of a contamination degree determination level (third embodiment).
FIG. 10 is a time chart showing a waveform of a contamination degree determination level (third embodiment).
FIG. 11 is a graph showing the relationship between ventilation permission time and blower voltage (fourth embodiment).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vehicle air conditioner 2 Duct 3 Inside / outside air switching door (inside / outside air switching means)
4 Blower 9 Exhaust gas sensor (pollution degree detection means)
10 Air conditioning control device (inside / outside air control means)
21 Inside air inlet 22 Outside air inlet

Claims (4)

(A) a duct for sending air into the passenger compartment, having an inside air inlet for sucking air inside the passenger compartment and an outside air inlet for sucking air outside the passenger compartment;
(B) the inside air inlet and to close the open-out before Kigaiki suction port inside air recirculation mode, inside and outside air switching means for switching the air inlet mode to the inside air inlet to a closed Ji before Kigaiki suction open mouth outside air introduction mode When,
(C) a pollution degree detection means for detecting a detection value related to the pollution degree of air outside the passenger compartment;
(D) During a predetermined inside air holding time, the set value for performing comparison with the detection value of the contamination degree detecting means is held at the inside air circulation mode by setting it to a high level higher than the standard value,
After the predetermined inside air retention time has elapsed, the set value is returned to the standard value for a predetermined ventilation permission time, and then the set value is continuously or stepwise reduced with the lapse of time to thereby reduce the contamination. When the detection value of the degree detecting means is higher than the set value, the car dual air conditioner having a inner and outer air control means for controlling said external air switching means to switch from the inside air circulating mode to the outside air introduction mode. The vehicle air conditioner according to claim 1,
The air conditioning apparatus for vehicles, wherein the inside / outside air control means sets the set value to a constant value during an inside air holding time in which the suction port mode is held in the inside air circulation mode. The vehicle air conditioner according to claim 2,
The vehicle air conditioner is characterized in that the inside / outside air control means changes the inside air holding time in which the suction port mode is held in the inside air circulation mode to be shorter as the number of passengers is larger. The vehicle air conditioner according to claim 1,
The vehicle air conditioner is characterized in that the inside / outside air control means changes a reduction amount for decreasing the set value continuously or stepwise so as to increase as the number of passengers increases.

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