JPH07228130A - Air conditioner for vehicle - Google Patents

Abstract

PURPOSE:To perform the prevention of entry of foul air and the prevention of glass fogging in the well-balanced state so as to improve the safety and amenity of travel by giving priority to the prevention of glass fogging of a vehicle at the time of low outside air temperature, and giving priority to the prevention of entry of foul airside air into the vehicle interior at the time of high outside air temperature. CONSTITUTION:In the case of the output value TG of a gas sensor, that is, the foul degree of outside air, being larger than the reference value TL, an internal-external air switching damper is switched to an internal air circulating mode. In the case of changing into a state of being smaller than the reference value TL afterwards, the timer time T1 is set. The timer time T1 is set to 60 seconds when the outside air temperature is 20 deg. or higher, to 20 seconds at the time of 0 deg.C or lower, and shorter as the outside air temperature is lower between 20 deg.C and 0 deg.C. The glass of a vehicle is more liable to be fogged as the outside air temperature is lower, and the air temperature in the vehicle interior rises and the glass is more liable to be fogged as the time to keep the internal air circulating mode is longer. The temperature rise in the vehicle interior is therefore suppressed to prevent the fogging of the glass by shortening the timer time T1 as the outside air temperature is lowered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner for a vehicle which automatically switches between an inside air mode and an outside air mode depending on the degree of contamination of the air outside the passenger compartment.

[0002]

2. Description of the Related Art As a conventional art of the above-mentioned vehicle air conditioner, there is one disclosed in Japanese Patent Publication No. 62-53367. The operation of this prior art will be described with reference to FIG. In this conventional technique, when the degree of contamination of the air outside the vehicle compartment detected by the gas sensor becomes large and the sensor output becomes equal to or higher than the set value A, the inside / outside air mode is switched to the inside air circulation mode (REC). Then, from this state, the sensor output becomes the set value B or less, and when the state of the set value B or less continues for the predetermined time T, the inside / outside air mode is switched to the outside air introduction mode (FRS).

[0003]

However, in the case of the above-mentioned prior art, the internal air circulation mode is changed because the sensor output does not switch to the outside air introduction mode unless the state where the sensor output becomes the set value B or less continues for a predetermined time T or more. It will be maintained longer. As a result, there is a problem that the humidity of the air in the vehicle compartment gradually rises due to the breathing and sweating action of the occupant, and the windshield and side glass of the vehicle become cloudy, hindering the occupant's view.

It is possible to shorten the predetermined time T in order to prevent fogging of the windshield and side windows of the vehicle. However, when driving in urban areas, the exhaust gas of the preceding vehicle is detected at each intersection stop, and the outside air introduction mode is set. When the vehicle is switched to the inside air circulation mode and starts, the sensor output immediately decreases, so that hunting occurs in which the inside air circulation mode returns to the outside air introduction mode, and a preferable operation of the air conditioner cannot be expected.

Further, in the above-mentioned prior art, it is conceivable to increase the set value A to shorten the time during which the mode is switched to the inside air circulation mode and to make the windshield and side glass of the vehicle less likely to be fogged. However, in the summer when the outside air temperature is high, the windshield and side windows of the vehicle are hardly fogged, and the set value A
Increasing the value makes it more neglected in terms of preventing the entry of dirty air outside the vehicle.

As described above, when the emphasis is placed on preventing the entry of dirty air outside the vehicle compartment, the windshield and side windows of the vehicle become fogged, and when the emphasis is placed on preventing the windshield and side glasses of the vehicle from becoming fogged, There arises a problem that dirty air outside the room enters. Therefore, in view of the above problems, it is an object of the present invention to prevent impurities contained in the air outside the vehicle compartment from entering the vehicle interior and to prevent the windshield and side glass of the vehicle from being fogged in a well-balanced manner. .

[0007]

In order to achieve the above object, the present invention provides an air passage for guiding air into a passenger compartment and an air upstream side portion of the air passage. An outside air introduction port that communicates with the outside of the vehicle compartment to take in the air outside the vehicle compartment into the air passage and an air upstream side portion of the air passage that communicates with the vehicle compartment and takes in the air inside the vehicle compartment into the air passage. An inside air / outside air opening / closing means for opening / closing the inside air / air inlet and the outside air / air inlet.
An inside / outside air opening / closing driving means for operating the inside / outside air opening / closing means, a dirt detecting means for detecting a dirt degree of the air outside the vehicle compartment, a physical quantity detecting means for detecting a physical quantity related to an air temperature outside the vehicle compartment, and First determining means for determining whether or not the stain degree detected by the stain detecting means is larger than a predetermined reference value, and when the first determining means determines that the stain degree is larger than the predetermined reference value, First inside / outside air control means for controlling the inside / outside air opening / closing drive means so that the outside air introduction port is closed and the inside air introduction port is opened;
Second determining means for determining whether the degree of contamination has changed from being larger than the predetermined reference value to being smaller.
When it is determined by the second determination means that the degree of dirt is smaller than the predetermined reference value, it is determined whether or not the degree of dirt is smaller than the reference value for a predetermined time after the determination. If it is determined by the third determining means and the third determining means that the degree of contamination is smaller than the reference value continuously for a predetermined time, the outside air inlet is opened and the inside air inlet is closed. A second inside / outside air control means for controlling the inside / outside air opening / closing driving means, and a delay time setting for setting the predetermined time shorter as the physical quantity detected by the physical quantity detecting means becomes an amount corresponding to a low outside air temperature. It is the gist to have means.

Further, as described in claim 2, the physical quantity detecting means may be constituted by an outside air temperature detecting means for detecting an air temperature outside the vehicle compartment. Further, as described in claim 3, a set temperature means for setting the temperature inside the vehicle interior and an outside air temperature detection means for detecting the air temperature outside the vehicle interior are provided, and at least the set temperature and the outside air temperature are: A target blowout temperature calculating means for calculating a target blowout temperature of air blown outside the vehicle may be provided, and the physical quantity detecting means may detect the target blowout temperature.

Further, in the invention according to claim 4, an air passage for guiding the air into the vehicle compartment and an air upstream side portion of the air passage are formed to communicate with the outside of the vehicle compartment and the air outside the vehicle compartment is communicated with the air passage. An outside air introduction port for taking in air, and an inside air introduction port formed in an air upstream side portion of the air passage for communicating with the vehicle interior to take in the air in the vehicle interior to the air passage, the outside air introduction port and the inside air. Opening / closing means for opening / closing the inlet, actuating means for operating the opening / closing means, dirt detecting means for detecting the degree of dirt outside the vehicle compartment, and physical quantity detecting means for detecting a physical quantity related to air temperature outside the vehicle interior. A determination unit that determines whether the degree of contamination detected by the contamination detection unit is greater than a predetermined reference value; and, when the determination unit determines that the contamination degree is greater than the predetermined reference value, First inside / outside air control means for controlling the inside / outside air opening / closing drive means so that the outside air introduction port is closed and the inside air introduction port is opened; and if the degree of contamination is smaller than the predetermined reference value by the first determination means. When determined, the second inside / outside air control means for controlling the inside / outside air opening / closing drive means such that the inside air introduction port is closed and the outside air introduction port is opened, and the physical quantity detected by the physical quantity detection means is low. The gist of the present invention is to include a reference value setting unit that sets the reference value to be larger as the amount of the air temperature becomes higher.

Further, as described in claim 5, the physical quantity detecting means may be constituted by an outside air temperature detecting means for detecting an air temperature outside the vehicle compartment. Further, as set forth in claim 6, a set temperature means for setting the temperature inside the vehicle compartment and an outside air temperature detection means for detecting the air temperature outside the vehicle compartment are provided, and at least the set temperature and the outside air temperature are: A target blowout temperature calculating means for calculating a target blowout temperature of air blown outside the vehicle may be provided, and the physical quantity detecting means may detect the target blowout temperature.

[0011]

According to the first aspect of the present invention, the dirt detecting means detects the degree of dirt in the air outside the passenger compartment. Then, the first determination unit determines that the degree of contamination detected by the contamination detection unit is
When it is determined that the value exceeds the predetermined reference value, the first inside / outside air control means controls the inside / outside air opening / closing drive means such that the outside air inlet is closed and the inside air inlet is opened. As a result, air outside the vehicle is less likely to enter the vehicle.

When it is determined by the second determining means that the degree of contamination is smaller than the predetermined reference value, the third determining means continues the predetermined time set by the delay time setting means after the determination. When it is determined that the degree of contamination is smaller than the reference value, the second inside / outside air control means controls the inside / outside air opening / closing drive means so that the outside air introduction port is opened and the inside air introduction port is closed.

By the way, the delay time setting means sets the predetermined time so that the physical quantity detected by the physical quantity detecting means becomes shorter as it becomes an amount corresponding to a low outside air temperature. Therefore, the inside air circulation mode continuation time is shortened at a low outside temperature when the windshield and the side glass are easily fogged, whereby the windshield and the side glass can be prevented from being fogged. Further, the inside air circulation mode continues for a long time at a high outdoor temperature where the windshield and the side glass are less likely to be fogged, which allows the preferable operation of the air conditioner to reliably prevent the entry of dirty air.

According to the third aspect of the present invention, the dirt detecting means detects the degree of dirt of the air outside the vehicle compartment. And
When the determination unit determines that the degree of contamination is greater than the reference value set by the reference value setting unit, the first inside / outside air control unit closes the outside air introduction port and opens the inside air introduction port. The opening / closing drive means is controlled. This prevents air outside the vehicle compartment from entering the vehicle compartment.

When the determination means determines that the degree of contamination is smaller than the reference value, the second inside / outside air control means controls the inside / outside air opening / closing drive means so that the outside air inlet is opened and the inside air inlet is closed. To do. By the way, the reference value setting means sets the reference value such that the physical quantity detected by the physical quantity detection means becomes larger as it becomes an amount corresponding to the low outside air temperature. Therefore, the reference value becomes large at a low outside temperature when the windshield and the side glass are easily fogged, and thereby the windshield and the side glass can be prevented from being fogged. Further, the reference value becomes small at a high outdoor temperature when the windshield and the side glass are less likely to be fogged, whereby it is possible to reliably prevent the air outside the vehicle from entering the vehicle interior.

As a result, the air outside the passenger compartment does not enter the passenger compartment, and when the windshield or side glass of the vehicle is easily fogged, it is possible to suppress an increase in humidity in the passenger compartment.

[0017]

According to the invention described above, the windshield and the side windshields of the vehicle are apt to be fogged, and the windshield and the side windshields are preferentially prevented from being fogged at a low outdoor temperature. When the outside temperature is high, the dirty air outside the passenger compartment enters into the passenger compartment with priority.Therefore, it is possible to prevent the dirty air from entering the passenger compartment and to prevent the windshield and side glass from being fogged in a well-balanced manner. it can. As a result, it is possible to improve the comfort inside the vehicle while maintaining the safety of the vehicle running.

[0018]

EXAMPLE A first example of the present invention will be described below. First, the overall configuration of the first embodiment will be described with reference to FIG. The vehicular air conditioner of the present embodiment is equipped with an automatic air conditioner control function for automatically maintaining the temperature inside the vehicle compartment at a set temperature. The vehicular air conditioner is roughly classified into the air conditioning unit 1 and the air conditioning unit 1. The ECU 27 controls each functional component of the air conditioning unit 1.

(Description of Air Conditioning Unit 1) Air Conditioning Unit 1
Is a duct 8 for introducing air into the vehicle compartment, an inside / outside air switching means 4 for selecting which of the air inside the vehicle compartment (inside air) and the air outside the vehicle compartment (outside air), and the inside / outside air switching means. Blower 2 for sending the air selected by 4 into the passenger compartment, and blower drive means 1 for driving this blower 2.
7, cooling means 12 for cooling the air flowing through the duct 8, heating means 9 for heating the cold air cooled by the cooling means 12, and heating amount adjusting means 13 for adjusting the temperature of the air blown into the vehicle compartment from the duct 8. Prepare

The inside / outside air switching means 4 is provided at the air suction port of the blower 2 and switches whether the air sucked into the duct 8 by the blower 2 is the inside air or the outside air. The inside air circulation port 6 for introducing the inside air into the duct 8, the outside air introduction port 7 for introducing the outside air into the duct 8 by communicating with the outside of the vehicle, and the inside air circulation port 6 and the outside air introduction port 7 are selected. An inside / outside air switching damper 14 is provided as an inside / outside air opening / closing means for selectively opening / closing. The inside / outside air switching damper 14 is driven by the inside / outside air opening / closing drive means 11, specifically, a servo motor, and is used in an inside air circulation mode for introducing inside air from the inside air circulation port 6 and outside air from the outside air introduction port 7. Is switched to the outside air introduction mode.

The blower 2 is provided in a portion of the duct 8 on the air downstream side of the inside / outside air switching means 4 and generates an air flow toward the vehicle compartment in the duct 8. The blower 2 includes a fan case 15, a fan 16, and a blower drive means 17 (specifically, a fan motor), and the blower drive means 17 rotationally drives the fan 16 according to a voltage applied from the blower drive circuit 5. Duct 8 for inside or outside air
To the passenger compartment via.

The duct 8 is arranged in the front of the passenger compartment, and a face duct 29, a foot duct 30, and a defroster duct (not shown) are formed at the air downstream side of the duct 8. Of these, the air that has passed through the face duct 29 is mainly blown with cool air from a face outlet (not shown) toward the upper body of the occupant. Also,
The air that has passed through the foot duct 30 is mainly blown with warm air toward the lower body of the occupant from a foot outlet (not shown). In addition, the air passing through the defroster duct 8 is mainly blown with warm air from a defroster outlet (not shown) toward the windshield or the side glass. In addition, in the portion of the duct 8 where the duct 8 branches into the face duct 29 and the foot duct 30, the outlet opening / closing means 3 for selectively opening / closing the face duct 29 and the foot duct 30.
2. Specifically, a duct switching damper is provided. The duct switching damper 32 is driven by an outlet opening / closing driving means 33, specifically, a servomotor. In this embodiment, the duct 8, the face duct 29, the foot duct 30, and the defroster duct form an air passage.

Specifically, the cooling means 12 is an evaporator which is a component of a refrigeration cycle (not shown), and is arranged in the duct 8 to cool the air passing therethrough. The refrigeration cycle of this embodiment is based on the evaporator 12
To the evaporator 12 via a compressor (not shown), a condenser (not shown), a receiver (not shown), and an expansion valve (not shown).
It is well known that a refrigerant is introduced into the.

The heating means 9 is specifically a heater core provided in a part of the duct 8 on the air downstream side of the evaporator 12, and heats the air passing therethrough by using engine cooling water as a heat source. The heating amount adjusting means 13 specifically includes a bypass passage 22 that bypasses the heater core 9.
And an air mix damper 10 which is provided on the air upstream side of the heater core 9 and adjusts the amount of cool air that has passed through the evaporator 12 to the heater core 9 and the amount of air to the bypass passage 22. Further, the air mix damper 10 is driven by an air mix damper drive means 21, specifically, a servo motor.

(Description of ECU 27) The ECU 27 is a control device for controlling each electric functional part of the air conditioning unit 1 described above, and includes a CPU (not shown), a ROM (not shown), and a RAM (not shown). . In addition, RO
A program for air-conditioning control is stored in M, and CP is stored based on the air-conditioning information temporarily stored in RAM.
U performs various calculations and processing.

The input terminals E to L of the ECU 27 include an inside / outside air switching manual switch 35 provided on an operation panel 34 operated by a vehicle occupant, a temperature setting device 36 for setting the temperature inside the vehicle, a blowout mode setting switch 37, Inside air temperature sensor 38 that detects the temperature of the air inside the vehicle, outside air temperature sensor 39 that detects the temperature of the air outside the vehicle, solar radiation sensor 40 that detects the amount of solar radiation entering the vehicle interior, and air immediately after passing through evaporator 12. Post-evaporation sensor 41 for detecting the temperature (hereinafter referred to as the post-evaporation temperature), a water temperature sensor 42 for detecting the cooling water temperature of the heater core 9, a gas sensor 43 for detecting the degree of contamination of the air outside the vehicle compartment, and a gas sensor 43 for turning on the gas sensor 43. The gas operation switches 44 for performing correction control of the inside / outside air switching damper 14 according to the output value are respectively connected. The gas sensor 43 constitutes the dirt detecting means, and the outside air temperature sensor 39 constitutes the outside air temperature adjusting means.

The output terminals A to C of the ECU 27 are connected to the servomotors 11, 21 and 33, and drive and control each damper via each servomotor. The output terminal D is connected to the blower drive circuit 5 and controls the air volume generated by the blower 2 via the blower drive circuit 5. When the occupant operates an auto switch (not shown) to select the auto air conditioner, the ECU 27 maintains the temperature inside the vehicle interior at the temperature set by the temperature setting device 36.
It automatically controls the inside / outside air mode, outlet temperature, air volume, and outlet mode.

Next, the control contents of this embodiment will be explained based on the flowchart of FIG. First, in step S1, initialization processing such as data and timer is performed, and the flag is set to 0. Next, in step S2, the operation panel 34
The temperature setting signal Tset from the temperature setting device 36 is read and stored.

Next, in step S3, a vehicle environmental condition affecting the air conditioning condition in the vehicle compartment is detected and stored. That is, the inside air temperature signal Tr from the inside air temperature sensor 38, the outside air temperature signal Tam from the outside air temperature sensor 39, the insolation amount signal Ts from the insolation sensor 40, the after evaporation temperature signal Te from the after evaporation sensor 41, and the water temperature from the water temperature sensor 42. Each signal of the signal Tw is read and stored.

In step S3, the manual signal from the inside / outside air switching manual switch 35 and the operation signal from the gas operation switch 44 are read and stored. Then, in step S4, in order to perform the automatic air conditioner control, the target outlet temperature TAO is calculated by the following mathematical expression 1 based on the signals read in step S2 and step S3.

[0031]

[Equation 1] TAO = Kset-Tset-Kr-Tr-Kam-
Tam-Ks.Ts + C Note that Kset, Kr, Tr, Kam, Ks, and C are correction constants. Next, in step S5, the target opening θ0 of the air mix damper 10 is determined by the following mathematical expression 2.

[0032]

## EQU2 ## θ0 = {(TAO-Te) / (Tw-Te)}
× 100 (%) Te is the post-evaporation temperature signal of the post-evaporation sensor 41, Tw
Is a water temperature signal of the water temperature sensor 42. Then, in step S6, the inside / outside air mode is determined based on the characteristics shown in FIG. Here, as shown in FIG. 3, the target outlet temperature TA
In the process of increasing O, the internal air circulation mode is switched to the external air introduction mode at TAO = −15 ° C., and the target outlet temperature T
In the process of lowering AO, the outside air introduction mode is switched to the inside air circulation mode at TAO = -20 ° C.

Then, in step S7, the blower drive circuit 5 determines the voltage applied to the fan motor 17 based on the characteristics shown in FIG. Then, in step S8, as shown in FIG.
The face (FACE) mode that blows wind from the face duct 29, the foot (FOOT) mode that blows wind from the foot duct 30, and the bi-level (B / B that blows wind from the face duct 29 and the foot duct 30) based on the characteristics shown in FIG. The blowout mode is determined between the L) modes.

Then, in step S9, the inside / outside air switching correction control, which is a main part of the present invention described later, is performed. The details of the inside / outside air switching correction control will be described later. And
In step S10, the above steps S4 to S
A control signal is output to the servo motor 11, the servo motor 21, the blower drive circuit 5, and the servo motor 33 so that the result obtained in 9 is obtained, and air conditioning control of the vehicle interior is performed.

Then, in step S11, it is determined whether or not the control cycle time τ has elapsed, and after the control cycle time τ has elapsed, the above step S is repeated again. Next, details of step S9 described above will be described based on the subroutine shown in FIG. It should be noted that this subroutine is started at the same time as step S8 is ended, and step S10 is executed at the same time as this subroutine is ended.

First, in step S901, it is determined whether the inside / outside air mode is automatically controlled.
If this determination result is YES, the process proceeds to step S902, and if NO, that is, if the inside / outside air switching manual switch 35 is ON, the process proceeds to step S908. In step S902, it is determined whether the gas operation switch 44 is ON, that is, whether the correction control of the inside / outside air switching damper 14 is performed according to the output value TG of the gas sensor 43. If this determination result is YES, the process proceeds to step S903, and N
In the case of O, the process proceeds to step S908.

In step S908, it is determined whether the inside / outside air mode is operating in the outside air introduction mode. If the determination result is NO, that is, if the operation is in the inside air circulation mode, the process proceeds to step S906, the inside / outside air mode is set to the inside air circulation mode, and then this subroutine is exited. If the decision result in the step S908 is YES, that is, if the operation is in the outside air introduction mode, the routine proceeds to a step S914, the inside / outside air mode is decided to the outside air introduction mode, and then this subroutine is exited.

In step S903, it is determined whether the output value TG of the gas sensor 43 is larger than the reference value TL. That is, it is determined whether or not the degree of contamination of the air outside the vehicle compartment is larger than a predetermined reference value. This judgment result is YES
In the case of, the flag is set to 1 in step S904, and then in step S905, step S
The timer counting at 912 is reset, and then the process proceeds to step S906. The inside / outside air mode is determined to be the inside air circulation mode.

On the other hand, if NO in step S903, the output value TG of the gas sensor 43 is determined to be a predetermined reference value TL by determining in step S909 whether or not the flag is set to 1. It is determined whether the state has changed from the larger state to the smaller state. Then, if the determination result is NO, the process proceeds to step S913,
The flag is set to 0, and the process proceeds to step S914.

On the other hand, if YES is determined in step S909, the timer time T1 is set in step S910.
Are set based on FIG. The details will be described later. When the timer time T1 is set in step S910, it is determined in step S911 whether this timer time T1 has elapsed. That is, after the output value TG of the gas sensor 43 is changed from the state larger than the reference value TL to the state smaller than the reference value TL, it is determined whether or not the state in which TG is smaller than TL continues for the timer time T1. This determination result is NO
In the case of, the timer counts the control cycle time τ in step S912, and the process proceeds to step S906. If the decision result in the step S911 is YES, a step S91
At 3, the flag is set to 1, and the process proceeds to step 914.

In the first embodiment, step S903 constitutes the first judging means, step S909 constitutes the second judging means, and step S911 constitutes the third judging means. Further, steps S906 and S10 constitute a first inside / outside air control means, steps S914 and S10 constitute a second inside / outside air control means, and step S910 constitutes a delay time setting means.

Further, each step shown in FIGS. 1 and 6 constitutes means for realizing each function. (Operation of First Embodiment) Next, the operation of the present embodiment will be specifically described with reference to FIGS. 1 and 7. For example, assume that the inside / outside air mode is automatically controlled and the gas sensor operation switch 44 is ON.

Further, the output value TG of the gas sensor, that is, the degree of contamination of the outside air changes as shown in FIG.
It is assumed that the time is t1. In this case, step S90
1, YES is determined in both steps S902, and in the next step S903, it is determined that the output value TG of the gas sensor 43 is smaller than the reference value TL, that is, the degree of contamination of the outside air is smaller than a predetermined reference value. Then, in the next step S904, since the flag is set to 1 in step S1, it is determined to be NO, and steps S913, 9
14, the inside / outside air mode is determined to be the outside air introduction mode in step S914.

Then, this routine is exited and step S
In step 10, the control signal is output to the servo motor 11 so as to be in the outside air introduction mode, and the inside / outside air switching damper 14 is driven. Next, a case where the time t2 comes and the output value TG of the gas sensor 43 becomes larger than the reference value TL as shown in FIG. 7 will be described.

In this case, in step S903, it is determined that the output value TG of the gas sensor 43 is larger than the reference value TL, that is, the degree of contamination of the outside air is larger than the predetermined reference value. Then, in step 904, the flag that was 0 is set to 1
, The inside / outside air mode is determined to be the inside air circulation mode in step S906, the routine exits from step S906.
In step 10, the control signal is output to the servo motor 11 so that the inside air circulation mode is set, and the inside / outside air switching damper 14 is driven. This prevents dirty air outside the vehicle from entering the vehicle interior.

After that, when the output value TG of the gas sensor changes to a state smaller than the reference value TL (the time at this time is t
3) will be described. In this case, it is determined as NO in step S903, that is, the output value T of the gas sensor 43.
It is determined that G is smaller than the reference value TL. In the next step S909, since the flag has been set to 1 in step S904 until then, it is determined to be YES. Then, in step S910, the timer time T1 is set based on FIG. Then, in step S912, it is determined whether or not the timer time T1 has elapsed. In this case, since the timer has not yet been counted, it is determined to be NO. Then, in the next step S912, the counting of the time after the output value TG of the gas sensor 43 is changed from the state larger than the predetermined reference value to the state smaller than the predetermined reference value is started. Is maintained.

Then, when the output value TG of the gas sensor 43 continues to be smaller than the reference value TL and the time reaches t4, the timer time T1 has not yet elapsed, so it is determined as NO in step 911, and the step is determined. In S912, the time from the state where the output value TG of the gas sensor 43 is larger than the predetermined reference value to the state where the output value TG is smaller is accumulated, and the accumulated result is T4-T3. Then, the inside air circulation mode is further maintained.

Further, when the output value TG of the gas sensor 43 continues to be smaller than the predetermined reference value TL and the time reaches t5, the timer time T1 set in step S910 has elapsed in step S911 (YES). It is determined and the flag is set to 0. Then, step S9
At step 14, the outside air introduction mode is determined, the routine exits this routine, and the process proceeds to step S10 to output to the servo motor 11 so as to be the outside air introduction mode.
Drive.

After that, if the output value TG of the gas sensor 43 is smaller than the reference value TL, the flag continues to be set to 0, so NO is determined in step S909, and the outside air introduction mode is set. Here, as shown in FIG. 8, the timer time T1 is such that the outside air temperature is the first predetermined temperature (2 in this embodiment).
At 0 ° C. or higher, it is set to a constant 60 seconds. Further, when the outside air temperature is equal to or lower than the second predetermined temperature (0 ° C. in this embodiment), it is kept constant for 20 seconds. Further, at 0 ° C. to 20 ° C., the lower the outside air temperature, the shorter the temperature, that is, the higher the outside air temperature, the longer the temperature.

That is, the lower the outside air temperature, the more easily the windshield and side windows of the vehicle become cloudy, and the longer the time when the inside air circulation mode is maintained, the more the breathing and sweating action of the occupant causes the humidity of the air inside the vehicle interior. And the windshield and side windows of the vehicle tend to become cloudy.
Therefore, by shortening the timer time T1 as the outside air temperature decreases, it is possible to suppress an increase in humidity in the vehicle compartment and prevent the windshield and the side glass from fogging in the vehicle.

When the outside air temperature is 20 ° C. or higher, the windshield and the side glass of the vehicle are not fogged so much. However, if the timer time T1 is made longer than this, the air in the vehicle interior is contaminated due to the occupant's breathing or the like. Because of this, the timer time T1 is kept constant. Further, when the outside air temperature is 0 degrees or lower, the windshield and side glass of the vehicle are more likely to be fogged.
If the value is shortened, the exhaust gas of the preceding vehicle is detected at each intersection stop when the vehicle is running in the city, and the mode is switched from the outside air introduction mode to the inside air circulation mode. When the vehicle starts, the output value of the gas sensor 43 immediately decreases, so the outside air circulation mode is changed. Returning to the introduction mode, the inside / outside air switching damper 14 is frequently switched, so that preferable operation of the air conditioner cannot be expected due to fluctuations in sound or air volume.

As described above, the windshield and the side glass are preferentially prevented from being fogged when the outside temperature is low and the windshield and the side glass are easily fogged. Since the dirty air of (1) is preferentially introduced into the vehicle interior, it is possible to prevent the dirty air from entering the vehicle interior and to prevent the windshield and the side glass from being fogged in a well-balanced manner. As a result, it is possible to improve the comfort inside the vehicle while maintaining the safety of the vehicle running.

Although the first embodiment of the present invention has been described above, the present invention can also be applied to the second embodiment as described below. The second embodiment differs from the first embodiment only in the control content of step S9. Below, the second
The inside / outside air switching correction control of the embodiment will be described with reference to the flowchart of FIG.

First, in step S915, it is determined whether the inside / outside air mode is automatically controlled.
If the determination result is YES, the process proceeds to step S916, and if the determination result is NO, the process proceeds to step S921. Step S
At 916, it is determined whether the gas operation switch 44 is ON, that is, whether the correction control of the inside / outside air switching damper 14 is performed according to the output value TG of the gas sensor 43. If the determination result is YES, the process proceeds to step S917, NO.
In the case of, it progresses to step S921.

In step S921, it is determined whether the inside / outside air mode is operating in the outside air introduction mode. If the result of this determination is NO, that is, if the operation is in the inside air circulation mode, then the flow proceeds to step S919, the inside / outside air introduction mode is determined to be the inside air circulation mode, and then this subroutine is exited. Moreover, the determination result of step S921 is YES.
In the case of, that is, when operating in the outside air introduction mode, the process proceeds to step S922, the inside / outside air mode is determined to be the outside air introduction mode, and then this subroutine is exited.

In step S917, the reference value TL is set based on FIG. The details will be described later. Then, in step S918, the output value T of the gas sensor 43
It is determined whether G is larger than the reference value TL. That is, it is determined whether or not the degree of contamination of the air outside the vehicle compartment is larger than a predetermined reference value. If this determination result is YES,
In step S919, the inside / outside air introduction mode is set to the inside air circulation mode.

On the other hand, if "NO" is determined in the step S918, the inside / outside air mode is set to the outside air introduction mode in a step S922. In addition, in the second embodiment, the determination means in step S918 and step S91.
9 and step S10 constitute a first inside / outside air control means, and steps S922 and S10 constitute a second inside / outside air control means. In step 917, the reference value setting means is configured.

Further, each step shown in FIG. 6 and FIG. 9 constitutes means for realizing each function. Here, as shown in FIG. 8, the reference value TL is constant when the outside air temperature is the first predetermined temperature (0 ° C. in this embodiment) or lower and the second predetermined temperature (20 ° C. in this embodiment) or higher. There is. Further, in the range of 0 to 20 degrees, the lower the outside air temperature, the larger the temperature becomes, that is, the higher the outside air temperature, the smaller the temperature becomes.

That is, when the outside air temperature is 0 to 20 degrees, the windshield and side glasses of the vehicle are more likely to be fogged as the outside air temperature is lower. Therefore, the reference value TL is increased to make the inside / outside air mode less likely to become the inside air circulation mode. This suppresses an increase in humidity in the passenger compartment due to the breathing and sweating of the occupant. Further, when the outside air temperature is 20 degrees or more, the windshield and the side glass of the vehicle are not so fogged, the reference value TL is set to the minimum value, and dirty air outside the vehicle is allowed to enter the vehicle interior as much as possible. prevent.
However, if the reference value TL is made smaller than this, hunting will occur or the preferable operation of the air conditioner will not be possible, so the reference value TL is kept constant.

Further, when the outside air temperature is 0 ° C. or lower, the windshield and the side glass of the vehicle are more likely to be fogged. However, if the reference value TL is increased more than this, air outside the passenger compartment enters the passenger compartment, and the occupant is injured. Since the discomfort increases, the reference value TL is kept constant. As a result, the same effect as that of the first embodiment can be obtained. Next, a third embodiment will be described. The third embodiment differs from the first embodiment only in step S910.

In the third embodiment, step S9 shown in FIG.
The timer time setting in 10 is performed according to the target outlet temperature TAO calculated based on the above-mentioned mathematical expression 1. Target outlet temperature T
The lower the outside air temperature, the higher the AO. Therefore, the higher the target blowout temperature TAO, the shorter the timer time T1. That is, the lower the target outlet temperature TAO, the longer the timer time T1.

Next, a fourth embodiment will be described. The fourth embodiment differs from the second embodiment only in step S917. In the fourth embodiment, step S9 shown in FIG.
The reference value setting in 17 is performed according to the target outlet temperature TAO. Specifically, the reference value TL is set larger as the target outlet temperature TAO is higher, that is, the reference value TL is set smaller as the target outlet temperature TAO is lower.

Here, the temperature setter 36 constitutes the set temperature means, the outside air temperature sensor 39 constitutes the outside air temperature detecting means, and the step S4 constitutes the target outlet temperature calculating means. Further, in the above embodiment, when the first determining means determines that the degree of contamination of the outside air is larger than the predetermined reference value, the inside / outside air mode is switched to the inside air circulation mode. The inside / outside air mode may be switched to the inside air circulation mode when the rate of increase is equal to or higher than a predetermined rate. In this case, the predetermined time is set shorter as the outside air temperature is lower or the target outlet temperature TAO is higher as in the first or third embodiment. Further, the higher the outside air temperature or the target outlet temperature TAO, the smaller the above-mentioned predetermined increase rate.

Further, as the outside air temperature becomes lower or the target outlet temperature TAO becomes higher, the timer time T1 may be shortened and at the same time the reference value TL may be increased. Further, although the air conditioner having the automatic air conditioner function has been described in the first to fourth embodiments, the inside / outside air switching damper 14 can be used for the manual air conditioner in which the occupant manually sets the outlet temperature, the outlet mode, and the air volume. Can be applied if a system capable of drive control by an electric signal is installed.

[Brief description of drawings]

FIG. 1 is a flowchart showing the contents of inside / outside air switching correction control in a first embodiment of the present invention.

FIG. 2 is an overall configuration diagram of an air conditioner according to first to fourth embodiments of the present invention.

FIG. 3 is a characteristic diagram showing a relationship between a target outlet temperature TAO and an inside / outside air mode in the first to fourth embodiments.

FIG. 4 is a characteristic diagram showing a relationship between a target outlet temperature TAO and an air volume in the first to fourth embodiments.

FIG. 5 is a characteristic diagram showing the relationship between the target outlet temperature TAO and the outlet mode in the first to fourth embodiments.

FIG. 6 is a flowchart showing a flow of overall control in the first to fourth embodiments.

FIG. 7 is a specific operation diagram of the inside / outside air switching damper in the first embodiment.

FIG. 8 is a characteristic diagram showing the relationship between the outside air temperature, the timer time T1 and the outside air temperature in the first embodiment.

FIG. 9 is a flowchart showing the contents of inside / outside air switching correction control in the second embodiment of the present invention.

FIG. 10 is an outside air temperature and a reference value T in the second embodiment.
It is a figure which shows the relationship with L.

FIG. 11 is a diagram showing a specific operation of the inside / outside air switching damper in the conventional vehicle air conditioner.

[Explanation of symbols]

 6 Inside air introduction port 7 Outside air introduction port 8 Duct (air passage) 11 Servo motor (inside / outside air opening / closing driving means) 14 Inside / outside air switching damper (inside / outside air opening / closing means) 27 ECU 29 Face duct (air passage) 30 Foot duct (air passage) ) 36 temperature setter (set temperature means) 39 outside air temperature sensor (outside air temperature detection means) 43 gas sensor (dirt detection means)

Claims (6)

[Claims] 1. An air passage for guiding air into a vehicle compartment, and an outside air inlet formed in an air upstream side portion of the air passage for communicating with the outside of the vehicle and introducing air outside the vehicle into the air passage. An inside air introduction port that is formed at an air upstream side portion of the air passage and communicates with a passenger compartment to take air in the passenger compartment into the air passage; and an inside and outside air that opens and closes the outside air introduction opening and the inside air introduction opening. Opening / closing means, inside / outside air opening / closing driving means for operating the inside / outside air opening / closing means, dirt detecting means for detecting the degree of dirt in the air outside the vehicle compartment, and physical quantity detection for detecting a physical quantity related to the air temperature outside the vehicle compartment Means, first judging means for judging whether or not the degree of dirt detected by the dirt detecting means is larger than a predetermined reference value, and if the dirt degree is larger than the predetermined reference value by the first judging means Once determined, a first inside / outside air control means for controlling the inside / outside air opening / closing drive means such that the outside air introduction port is closed and the inside air introduction port is opened; and a state in which the degree of contamination is larger than the predetermined reference value. Second determination means for determining whether or not the state has become small, and when the second determination means determines that the degree of contamination has changed from being larger than the predetermined reference value to being small, the determination is continued for a predetermined time. And a third judging means for judging whether or not the dirt level is lower than the reference value, and the third judging means judges that the dirt level is lower than the reference value for a predetermined time. Cod,
The second inside / outside air control means for controlling the inside / outside air opening / closing drive means so that the outside air introduction port is opened and the inside air introduction port is closed, and the physical quantity detected by the physical quantity detection means corresponds to a low outside air temperature. A vehicle air conditioner, comprising: a delay time setting means for setting the predetermined time to be shorter as the amount becomes larger. 2. The vehicle air conditioner according to claim 1, wherein the physical quantity detecting means is an outside air temperature detecting means for detecting an air temperature outside the vehicle compartment. 3. A set temperature means for setting the temperature inside the vehicle compartment, an outside air temperature detection means for detecting the air temperature outside the vehicle compartment, and a target blowout of air blown out of the vehicle compartment based on at least the set temperature and the outside air temperature. The air conditioner for a vehicle according to claim 1, further comprising a target outlet temperature calculating unit for calculating a temperature, wherein the physical quantity detecting unit detects the target outlet temperature. 4. An air passage for guiding air into the passenger compartment, and an outside air introduction port formed in an air upstream side portion of the air passage for communicating with the outside of the passenger compartment and for introducing air outside the passenger compartment into the air passage. An inside air introduction port that is formed at an air upstream side portion of the air passage and communicates with a passenger compartment to take air in the passenger compartment into the air passage; and an inside and outside air that opens and closes the outside air introduction opening and the inside air introduction opening. Opening / closing means, inside / outside air opening / closing driving means for operating the opening / closing means, dirt detecting means for detecting the degree of dirt outside the vehicle compartment, physical quantity detecting means for detecting a physical quantity related to air temperature outside the vehicle compartment, and the dirt When the determination unit determines whether the degree of contamination detected by the detection unit is greater than a predetermined reference value, and the determination unit determines that the degree of contamination is greater than the predetermined reference value, the outside air conduction A first inside / outside air control means for controlling the inside / outside air opening / closing drive means so that the mouth is closed and the inside air inlet is opened, and if the degree of contamination is determined to be smaller than the predetermined reference value by the determination means, A second inside / outside air control means for controlling the inside / outside air opening / closing driving means so that the inside air inlet is closed and the outside air inlet is opened, and the physical quantity detected by the physical quantity detecting means corresponds to a low outside air temperature. And a reference value setting means for setting the reference value to a higher value. 5. The vehicle air conditioner according to claim 1, wherein the physical quantity detecting means is an outside air temperature detecting means for detecting an air temperature outside the vehicle compartment. 6. A set temperature means for setting the temperature inside the vehicle compartment, an outside air temperature detection means for detecting the air temperature outside the vehicle compartment, and a target blowout of air blown out of the vehicle compartment based on at least the set temperature and the outside air temperature. The air conditioner for a vehicle according to claim 1, further comprising a target outlet temperature calculating unit for calculating a temperature, wherein the physical quantity detecting unit detects the target outlet temperature.