JP3711679B2 - Inside / outside air control device for vehicle air conditioner - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inside / outside air control device for an air conditioner for a vehicle, and more particularly, to switching from an outside air mode to an inside air mode when air outside a passenger compartment is dirty.
[0002]
[Prior art]
A conventional technique is described in Japanese Patent Laid-Open No. 8-72528. In this document, an inside / outside air switching control device using a gas sensor for detecting the degree of dirt in the air outside the passenger compartment is described. Specifically, a control processing value for the degree of dirt is calculated by a ratio between the degree of dirt outside the passenger compartment detected by the gas sensor and a predetermined update reference value, which is the standard degree of dirt, and the control processing value is determined to be a predetermined dirt level. When it exceeds the degree, the servo motor automatically switches the inside / outside air switching door from the outside air mode to the inside air mode.
[0003]
Here, the update reference value is updated according to the degree of dirt outside the passenger compartment detected by the gas sensor, and the lowest value of the degree of dirt detected by the gas sensor while power is supplied to the gas sensor. It is set to be updated. When the power supply to the gas sensor is stopped (ignition switch off), when the power is supplied to the gas sensor (ignition switch on), the previous reference value set immediately before the power supply stop Is used as the latest update reference value.
[0004]
[Problems to be solved by the invention]
However, the above-described conventional apparatus has the following problems.
In the gas sensor as described above, the output value greatly varies depending on the humidity. For example, when the gas sensor is composed of a semiconductor element such as SiO ₂ , the degree of contamination to be detected becomes greater than the actual degree of contamination as the humidity increases.
[0005]
As a result, as shown in FIG. 7, it is assumed that the previous reference value updated immediately before turning off the ignition switch was set when the weather was low, such as when the weather was low, and then, for example, when it rained If the ignition switch is turned on when the humidity is high and the latest updated reference value is the previous reference value, the gas sensor erroneously detects that the detected contamination level is greater than the actual contamination level. Therefore, there is a problem that the air conditioning feeling deteriorates.
[0006]
Further, in the conventional apparatus, when the previous reference value is set to be very small (for example, the vehicle travels in a mountainous area where the outside air is very clean), there are the following problems.
In other words, if the previous reference value is used when the ignition switch is turned on again, the outside air is actually not very dirty, but in the calculation of the control processing value, the degree of contamination detected by the gas sensor and the previous reference value As the difference between the two increases, the degree of contamination of the control processing value increases, resulting in the inside air mode, and the air conditioning feeling deteriorates.
[0007]
Therefore, according to the present invention, when electric power is supplied to the gas sensor and the detection of the degree of contamination of the outside air is started, the inside / outside air control suitable for the air conditioning feeling of the occupant can be accurately performed according to the degree of contamination of the outside air. An object of the present invention is to provide an inside / outside air switching control device for a vehicle air conditioner.
[0008]
[Means for Solving the Problems]
The present invention employs the following technical means to achieve the above object.
In the first aspect of the present invention, first update setting means for updating and setting the first update reference value that is the reference dirt degree so as to be the lowest dirt degree detected by the dirt degree detecting means (10); When the detection of the degree of contamination is started, second update setting means for correcting the update reference value immediately before the power supply is stopped so that the degree of contamination gradually increases as time passes. Among the first update reference value updated and set by the first update setting means and the correction reference value corrected by the second update setting means, the one with the smaller degree of contamination is set as the latest update reference value. And third update setting means.
[0009]
The operation of the present invention will be specifically described with reference to FIG. Note that symbols in the description are given for easy understanding of the description. For example, when power is supplied at time A in FIG. 6, the third update setting unit determines that the previous update reference value VCLR is less than the previous update reference value VCLR ′ detected by the detection unit. 'Becomes the latest update reference value VCLR 2.
[0010]
Thereafter, when time elapses and time B is reached, the second update setting means corrects the immediately previous update reference value VCLR ′ so that the degree of contamination gradually increases as time elapses, and sets the correction reference value VCLR 1. Is done.
At this time, when the degree of contamination detected by the detection means is smaller than the correction reference value VCLR 1 and the previous update reference value VCLR 2 by the third update setting means, the detection means detects the latest update reference value. The degree of contamination.
[0011]
On the other hand, according to the present invention, the degree of contamination detected by the detection means is greater than the correction reference value VCLR ′ and the previous update reference value VCLR 2 by the third update setting means, and the correction reference value VCLR 1 is the previous update reference. When the degree of contamination is smaller than the value VCLR 2, the latest reference value VCLR becomes the corrected correction reference value VCLR 1. Accordingly, the amount of change between the degree of contamination detected by the detection means and the correction reference value VCLR 1 is reduced.
[0012]
As a result, the degree of contamination of the immediately previous update reference value VCLR ′ that was set immediately before the power supply is stopped is set to be very small, or the detection means detects the humidity when the power is supplied again. Even if the degree of contamination is greater than the actual level, the latest reference value VCLR ′ is corrected so that the degree of contamination increases as time passes. The inside / outside air control suitable for the ring can be performed.
[0013]
In invention of Claim 2,
Update setting means
When power is supplied to the contamination degree detection means (10) and the contamination degree detection means (10) detects the degree of contamination of outside air in the passenger compartment, the update immediately before the supply of power is stopped. The reference value is corrected so that the degree of dirt gradually increases as time passes to obtain a correction reference value. Of the correction reference value and the last update reference value set last time, the one with the smaller degree of dirt is the latest The update reference value is used.
[0014]
Also by this, the same effect as that of the first aspect of the invention can be obtained.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an overall configuration diagram of an inside / outside air control device of a vehicle air conditioner. FIG. 2 shows a detailed view of the main part of the inside / outside air switching device.
As shown in FIG. 1, a vehicle air conditioner 1 is installed in the vehicle interior. This vehicle air conditioner 1 has a known air conditioner case 2 that forms an air passage to the passenger compartment. A known inside air inlet 3 and outside air inlet 4 are provided on the most upstream side of the air conditioning case 2. The inside air introduction port 3 is for taking in vehicle interior air (hereinafter referred to as inside air) into the air conditioning case 2, and the outside air introduction port 4 is used for taking outside air inside the vehicle interior (hereinafter referred to as outside air) into the air conditioning case 2. is there.
[0016]
The inside air introduction port 3 and the outside air introduction port 4 can be selectively opened and closed by an inside / outside air switching door 6 which is an inside / outside air switching member in the present embodiment. The inside / outside air switching door 6 is rotatably supported by the air conditioning case 2 to switch and adjust the ratio between the inside air and the outside air taken in from the inside air introduction port 3 and the outside air introduction port 4.
The inside / outside air switching door 6 is driven by a servo motor 7 as an electric driving means. The servo motor 7 is driven and controlled by a control device 20 to be described later, whereby the inside / outside air switching door 6 can operate within the range of the arrow A in FIG.
[0017]
In the present embodiment, one end of the operating range showing the inside and outside air switching door 6 to close the outside air introduction port 4 while opening the inside air guide inlet 3 as shown in FIG. 2 as outside air mode in FIG. 2 b 2 and the other end side of the operating range shown in FIG. 2a, the outside / air switching door 6 is opened so that the outside air introduction port 4 is opened and the inside air introduction port 3 is closed. To the inside air mode that guides the inside air into the air conditioning case 2.
[0018]
The air conditioning case 2 is provided with a blower 5 that generates an air flow toward the passenger compartment on the air downstream side of the inside air introduction port 3 and the outside air introduction port 4. The blower 5 sucks outside air or inside air into the air conditioning case 2 in accordance with the two inside / outside air modes.
Although not shown, the air conditioning case 2 is provided with a known evaporator that cools the air downstream of the blower 5, and a known heater core that heats the air downstream of the evaporator. ing. In the air conditioning case 2, a well-known air mix door is arranged as a means for adjusting the temperature of the conditioned air.
[0019]
Further, a plurality of air passages for guiding air into the passenger compartment are formed on the air downstream side of the air conditioning case 2. This air passage is a well-known air passage for the face for blowing conditioned air toward the upper body of the occupant, an air passage for the foot for blowing conditioned air toward the lower body of the occupant, and a vehicle window An air passage for a defroster for blowing conditioned air toward the inner surface of the glass is formed. In addition, the flow of the air to these three air passages is controlled by the well-known blowing switching door.
[0020]
As shown in FIG. 1, a gas sensor 10 is installed in the engine room 9 of the vehicle as means for detecting the degree of contamination of outside air. Here, the gas sensor 10 may be a well-known one, but the gas sensor 10 in the present embodiment is a semiconductor element that reacts to a harmful gas such as carbon monoxide (CO) or nitrogen carbide (HC) (for example, SiO _2). ) And an electric heater for increasing the reaction speed of the semiconductor element. The gas sensor 10 is configured such that the electrical resistance value decreases and the output value (output voltage) VDgs decreases as the concentration of the harmful gas (the degree of contamination of the outside air) increases. Further, the gas sensor 10 has a characteristic that the output value VDGS becomes lower and the degree of contamination becomes higher as the humidity of the outside air becomes higher.
[0021]
Next, the control device 20 will be briefly described. The control device 20 is a computer means that includes a RAM, a ROM, and the like. When the ignition switch 30 shown in FIG. 1 is turned on, the control device 20 is supplied with electric power from a vehicle battery (not shown). In addition, when the ignition switch 30 is turned on, the gas sensor 10 is also supplied with electric power from the in-vehicle battery, and detects the degree of contamination of the outside air.
[0022]
In addition to the gas sensor 10 as an input terminal, the control device 20 includes a sensor group 21 (for example, an inside air temperature sensor, an outside air temperature sensor) that detects an environmental factor that affects the air conditioning environment, and an air conditioner provided in the vehicle interior. An operation panel 22 is connected.
The air conditioning operation panel 22 is automatically set based on a signal from a temperature setter 22a for setting the set temperature in the passenger compartment and the sensor group 21 so that the set temperature is set by the temperature setter 22a. An auto (AUTO) switch 22b for controlling air conditioning, an off (OFF) switch 22c for stopping the operation of the vehicle air conditioner 1, and an inside / outside air switch 22d for manually selecting the inside air mode or the outside air mode are provided. When the auto switch 22b is turned on, the blower 5 is started, and when the off switch 22c is turned on, the blower 5 is stopped.
[0023]
Further, the control device 20 is connected to the servo motor 7 and the blower 5 as output terminals.
Next, the control content of the inside / outside air switching door 6 according to the detection value of the gas sensor 10 which is the main part of the present invention will be described. FIG. 3 is a flowchart showing the control contents. Here, this flowchart is performed when the auto switch 22b is in an on state when the ignition switch 30 is turned on and the blower 5 is in a driving state. The control cycle of this flowchart is several seconds.
[0024]
First, in step S100, initialization processing such as a timer is performed, a flag is set to 0, and the gas sensor 10 is warmed up. Here, the warm-up is to increase the reaction speed of the semiconductor element by warming the semiconductor element with the electric heater described above. The warm-up of the gas sensor 10 is performed for about 30 seconds when this flowchart is executed for the first time, and the process proceeds to step S200 only after 30 seconds have elapsed. During the warm-up, the inside / outside air mode is set to the inside air mode. Thereby, even if the outside air is dirty during warm-up, it is possible to prevent the outside air from entering the vehicle interior.
[0025]
Next, in step S200, a previous update reference value VCLR 2 = 0 described later is set. A detailed description of the previous update reference value VCLR 2 will be given later.
Subsequently, in step S300, an update reference value VCLR for performing inside / outside air control with the output value VDGS of the gas sensor 10 is set. Here, since the gas sensor 10 has a very large variation in detection accuracy depending on the semiconductor element, it is difficult to simply detect whether the outside air is dirty with the absolute value of the output value VDGS. Therefore, in the present embodiment, the degree of dirtiness of the outside air is detected by the amount of change with respect to the update reference value VCLR. The update reference value VCLR is an absolute value of an output value detected by the gas sensor 10. When the outside air is contaminated and the degree of contamination is large, the output value VDGS detected by the gas sensor 10 becomes small.
[0026]
The reference value VCLR will be described in detail later.
Next, in step S400, the output value VDGS of the gas sensor 10 is read, and the process proceeds to step S500. In step S500, a process value Ln used for an inside / outside air control process described later is calculated. This processing value Ln is calculated by the following formula 1.
[0027]
[Expression 1]
Process value Ln = Output value VDGS / Update reference value VCLR
That is, Equation 2 is a change amount with respect to the update reference value VCLR as described above, and the processing value Ln corresponds to the degree of dirtiness of the outside air in the arithmetic processing. The output value VDGS decreases as the outside air contamination level increases. Therefore, if the update reference value VCLR is constant, the processing value Ln decreases as the outside air contamination level increases.
[0028]
In step S600, the inside / outside air control process based on the output value VDGS is performed.
Hereinafter, the inside / outside air control process will be described. FIG. 4 is a flowchart showing the control contents of step S600. When the inside / outside air switch 22d is operated and the inside / outside air mode is manually determined, the following flowchart is not executed, and the inside / outside air mode is selected according to the setting of the inside / outside air switch 22d.
[0029]
First, in step S601, it is determined whether or not the processing value Ln is equal to or lower than a predetermined determination level Ls. Here, this determination level Ls is the minimum value of the degree of dirtiness of the outside air that makes the passenger feel uncomfortable. As described above, when the outside air is contaminated and the degree of contamination is large, the output value VDGS becomes small. Therefore, when the processing value Ln is equal to or less than the determination level Ls, the degree of contamination of the outside air is greater than a predetermined value and the occupant. Is when you feel uncomfortable. In this case, the process proceeds to step S602, and the inside / outside air mode is set to the inside air mode. As a result, dirty outside air does not enter the passenger compartment, and the passenger is not uncomfortable.
[0030]
On the other hand, when the processing value Ln is larger than the determination level Ls in step S601, the degree of dirtiness of the outside air is smaller than a predetermined value, the outside air is clean, and the passenger does not feel uncomfortable. The process proceeds to step S603. In step S603, the inside / outside air mode is set to the outside air mode.
Next, the setting of the update reference value VCLR which is the main part of the present invention described above will be described. FIG. 5 is a flowchart showing the setting contents of the reference value VCLR. Note that this step S300 is executed if the ignition switch 30 is turned on and electric power is supplied to the gas sensor 10, even if the automatic control switch 22b is not turned on.
[0031]
Further, the update reference value VCLR is set according to the flowchart shown in FIG. 5. Once the update reference value VCLR is set according to this flowchart, the update reference value VCLR is backed up even if the ignition switch is turned off. It is remembered. If the backed-up update reference value VCLR is the previous reference value VCLR ′ (the previous update reference value), the previous reference value VCLR ′ is set when the ignition switch is turned on again and this flowchart is executed again. Used to set the latest update reference value VCLR.
[0032]
In addition, since the update reference value VCLR is repeatedly updated in step S300, the previous update reference value VCLR 2 is the update reference value updated and set last in step S300.
Hereinafter, description will be made using the previous reference value VCLR ′, the latest update reference value VCLR, and the previous update reference value VCLR 2. The previous reference value VCLR ′, the latest update reference value VCLR, and the previous update reference value VCLR 2 are always set based on the output VDGS of the gas sensor 10. Therefore, the smaller the value, the more dirty the reference value VCLR ′. The degree increases.
[0033]
First, when the process proceeds to this flowchart for the first time immediately after the ignition switch is turned on, the previous reference value VCLR ′ is corrected by the following formula 1 in step S301.
[0034]
[Expression 2]
Correction reference value VCLR1 = previous reference value VCLR '-kt
Here, k is a constant, and t is an elapsed time from when the ignition switch is turned on.
Since the time t is 0 in this description, the correction reference value VCLR 1 is set to VCLR ′ in step S301.
[0035]
Subsequently, the routine proceeds to step S302, where the ignition switch 30 is turned on, and it is determined whether the previous update reference value VCLR 2 when this flowchart is executed is smaller than the actual output value VDGS of the gas sensor 10. The Here, for the sake of explanation, since it is immediately after the ignition switch 30 is turned on, since the previous update reference value VCLR 2 = 0 is set in step S200, the determination result in step S302 is always YES. Then, the process proceeds to step S303.
[0036]
In step S303, the previous update reference value VCLR 2 is set as the output value VDGS. Subsequently, the process proceeds to step S304, in which it is determined whether or not the correction reference value VCLR 1 (for explanation, VCLR ′) is equal to or greater than the previous update reference value VCLR 2 (for explanation, output value VDGS).
In step S304, it is determined that the correction reference value VCLR1 is smaller than the previous update reference value VCLR2, that is, the previous update reference value VCLR2 (output value VDGS) is less dirty than the correction reference value VCLR1. Then, the process proceeds to step S305. In step S305, the latest update reference value VCLR is set as the previous update reference value VCLR 2 (output value VDGS).
[0037]
That is, when the output value VDGS of the gas sensor 10 is less dirty than the previous update reference value VCLR 2 when the flowchart of FIG. 5 is executed for the first time, the latest update reference value VCLR is set to the output value VDGS. .
On the other hand, in step S304, it is determined that the correction reference value VCLR 1 is greater than or equal to the previous update reference value VCLR 2, that is, the previous update reference value VCLR 2 (output value VDGS) is greater in dirt level than the correction reference value VCLR 1. Then, the process proceeds to step S305. In step S305, the latest update reference value VCLR is set as the correction reference value VCLR 1 (VCLR ').
[0038]
As described above, in the present embodiment, immediately after the ignition switch 30 is turned on, the gas sensor 10 immediately after the ignition switch 30 is turned on, and the previous reference value VCLR ′ set immediately before the ignition switch 30 is turned off. Among the output values VDGS, the one with the smaller degree of contamination becomes the latest update reference value VCLR.
[0039]
Next, a case will be described in which this flowchart is exited and the process proceeds to this flowchart again. For the sake of explanation, the previous update reference value VCLR 2 is the previous output value VDGS.
First, in step S301, the correction reference value VCLR 1 is calculated using Equation 1 above. In this case, the control cycle time of the flowchart shown in FIG. 5 has elapsed since the ignition switch 30 was turned on. Therefore, the correction reference value VCLR 1 is corrected to be smaller than the previous reference value VCLR ′ and the degree of contamination is increased.
[0040]
Next, in step S302, it is determined whether or not the current output value VDGS is greater than or equal to the previous update reference value VCLR 2 (previous output value VDGS). In step S302, it is determined that the current output value VDGS is greater than or equal to the previous update reference value VCLR 2 (previous output value VDGS), that is, the current output value VDGS is less contaminated than the previous update reference value VCLR2. Then, the process proceeds to step S303, and the previous update reference value VCLR 2 is set as the current output value VDGS.
[0041]
On the other hand, in step S302, the current output value VDGS is smaller than the previous update reference value VCLR 2 (previous output value VDGS), that is, the current output value VDGS is more dirty than the previous update reference value VCLR 2. If it is determined, the process proceeds to step S303, the previous update reference value VCLR 2 is left as it is, and the process proceeds to step S304.
[0042]
Subsequently, in step S304, it is determined whether or not the correction reference value VCLR 1 is greater than or equal to the previous update reference value VCLR 2 set in step S302 or step S303.
When the correction reference value VCLR 1 is smaller than the previous update reference value VCLR 2 in step S304, that is, when the correction reference value VCLR 1 is larger than the contamination level of the previous update reference value VCLR 2, the process proceeds to step S305. In step S305, the latest update reference value VCLR is set as the previous update reference value VCLR2.
[0043]
On the other hand, when the correction reference value VCLR 1 is greater than or equal to the previous update reference value VCLR 2 in step S304, that is, when the correction reference value VCLR 1 is smaller than the contamination level of the previous update reference value VCLR 2, the process proceeds to step S306. In step S305, the latest update reference value VCLR is set as the correction reference value VCLR 1.
In this way, when the process proceeds to the flowchart shown in FIG. 5 twice or three times after the ignition switch 30 is turned on, the previous reference value VCLR ′ is gradually corrected so as to increase in step S301. Thus, the correction reference value VCLR 1 is set.
[0044]
In this embodiment, in step S301, the previous reference value VCLR ′ is corrected to about half in about 10 minutes. Accordingly, the correction amount (K · t) corrected each time the process proceeds to step S301 is very small with respect to the previous reference value VCLR ′.
As described above, in the present embodiment, the correction reference value VCLR 1 is set by correcting the previous reference value VCLR ′ so as to increase the degree of contamination as time passes, as described in the above “Means for Solving Problems”. If the correction reference value VCLR 1 is less dirty than the previous update reference value VCLR 2 and the current output value VDGS, the latest update reference value VCLR becomes the correction reference value VCLR 1. Therefore, even if the gas sensor 10 is affected by humidity and the output value VDGS becomes larger than the actual contamination level, the amount of change between the correction reference value VCLR 1 and the output value VDGS is small, that is, the processing value Ls. Since the degree of contamination is small, it is difficult to enter the inside air mode. As a result, the inside / outside air control suitable for the air conditioning feeling of the passenger can be performed.
[0045]
Even if the degree of contamination of the previous reference value VCLR ′ is set to be very small by driving the vehicle in a mountainous area where the outside air is very clean, if the ignition switch 30 is turned on, the previous reference value By correcting VCLR 'so as to increase the degree of contamination, the amount of change between the correction reference value VCLR 1 and the output value VDGS becomes small, so it is difficult to enter the inside air mode. As a result, the inside / outside air control suitable for the air conditioning feeling of the passenger can be performed.
[0046]
In addition, when the degree of contamination of the output value VDGS is smaller than the degree of contamination of the correction reference value VCLR 1, the latest updated reference value VCLR can be used as the output value VDGS of the gas sensor 10, and the degree of contamination of the outside air can be increased. The determination can be performed with high accuracy.
By the way, in the present embodiment, the correction reference value VCLR 1 is corrected so that the degree of contamination gradually increases as time elapses. Therefore, when this is repeated, the latest update reference value VCLR is always the value of the gas sensor 10. The output value is VDGS. The reason for this correction is as follows.
[0047]
In the gas sensor 10, the previous reference value VCLR ′ immediately before the ignition switch 30 is turned off is set according to the state of the outside air until immediately before the ignition switch 30 is turned off. Therefore, when the ignition switch 30 is turned on, it may be different from the outside air state (for example, humidity) just before the off.
When the ignition switch 30 is turned on and the above-described inside / outside air control process is performed, the update reference value VCLR set according to the state of the outside air at that time is used, so that the degree of contamination of the outside air at that time is obtained. Accordingly, the inside / outside air control needs to be performed with high accuracy.
[0048]
Therefore, in this embodiment, by correcting the previous reference value VCLR ′ so as to increase the degree of contamination in step S301, the determination result in FIG. 302 becomes YES while the flowchart shown in FIG. 5 is repeated. The latest update reference value VCLR becomes the output value VDGS. As a result, when the above-described inside / outside air control process is performed, the reference value VCLR can be set according to the state of the outside air at that time, and the outside air that has become dirty without being affected by the humidity can surely enter the vehicle interior. Can be prevented.
[0049]
(Other embodiments)
In the above embodiment, the processing value Ln is the ratio between the output value VDGS and the update reference value VCLR, but it may be the difference between the output value VDGS and the update reference value VCLR.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of an inside / outside air control device of a vehicle air conditioner according to an embodiment of the present invention.
FIG. 2 is a detailed view of the inside / outside air control device in the embodiment.
FIG. 3 is a flowchart showing control contents of the control device 20 in the embodiment.
FIG. 4 is a flowchart showing control contents of the control device 20 in the embodiment.
FIG. 5 is a flowchart showing the control content of the control device 20 in the embodiment.
FIG. 6 is a time chart showing control contents of the control device 20 in the embodiment.
FIG. 7 is a time chart showing control contents of a conventional control device.
[Explanation of symbols]
2 ... Air conditioning case, 3 ... Inside air introduction port, 4 ... Outside air introduction port, 6 ... Inside / outside air switching door,
7 ... Servo motor, 10 ... Gas sensor, 20 ... Control device.

Claims (2)

An air conditioning case (2) that forms an air passage to the passenger compartment, an inside / outside air switching member (6) that adjusts the ratio of the inside air to the outside air taken into the air conditioning case (2), and this inside / outside air switching member (6) An inside / outside air control device for a vehicle air conditioner having drive control means (7, 20) for automatically driving control and dirt level detection means (10) for detecting the degree of dirt of outside air by supplying electric power. Because
First update setting means for updating and setting a first update reference value that is a reference dirt degree so as to be the lowest dirt degree detected by the dirt degree detecting means (10);
When the detection of the contamination level is started, a second update setting for correcting the update reference value immediately before the power supply is stopped so that the contamination level gradually increases as time passes. Means,
Of the first update reference value updated and set by the first update setting means and the correction reference value corrected by the second update setting means, the one with the smaller degree of contamination is set as the latest update reference value. An inside / outside air switching control device for a vehicle air conditioner, characterized by comprising: latest update setting means. An air conditioning case (2) that forms an air passage to the passenger compartment, an inside / outside air switching member (6) that adjusts the ratio of the inside air to the outside air taken into the air conditioning case (2), and this inside / outside air switching member (6) Detected by a drive control means (7, 20) for automatically controlling driving, a dirt degree detecting means (10) for detecting the degree of dirt in the air outside the vehicle compartment by supplying electric power, and the dirt degree detecting means (10). An inside / outside air control device for a vehicle air conditioner, having update setting means for updating and setting an update reference value that is a reference dirt degree so as to achieve the lowest dirt degree,
The update setting means includes
When detection of the contamination level is started, the correction reference value is corrected by correcting the update reference value immediately before the power supply is stopped so that the contamination level gradually increases as time passes. age,
An inside / outside air switching control device for an air conditioner for a vehicle, characterized in that, of the correction reference value and the last update reference value set last time, the one with the smaller degree of contamination is set as the latest update reference value.

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