JP3326954B2 - Vehicle air conditioner - Google Patents

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, and more particularly to humidity control for preventing fogging of a window glass.

[0002]

2. Description of the Related Art Conventionally, in vehicle air conditioners, anti-fog control for preventing fogging of window glass has been performed (Japanese Utility Model Application Laid-Open No. 58-59611, Japanese Utility Model Application Laid-Open No. 59-14091).
No. 3). This anti-fogging control determines whether or not the window glass is fogged (anti-fogging determination) based on a comparison between the vehicle interior humidity and the anti-fogging determination value. The defrosting of the window glass is prevented by operating the refrigerant compressor of (1) to dehumidify the vehicle interior.

[0003]

However, in the conventional anti-fogging control, when the refrigerant compressor is switched from ON to OFF, water condensed in the refrigerant evaporator re-evaporates as the temperature of the refrigerant evaporator rises. As a result, the humidity of the blown air blown out from the outlet into the vehicle compartment rises rapidly (see FIG. 13). At this time, even if the vehicle interior humidity (average humidity in the vehicle interior) does not reach the limit humidity at which fogging occurs in the window glass, for example, the air outlet mode blows air into the window glass (defroster mode, foot differential mode, Or, in the case of a foot mode in which a small amount of air is blown toward the window glass, the window glass may be fogged. The present invention has been made based on the above circumstances, and has as its object to prevent a fogging of a window glass due to re-evaporation of moisture condensed in a refrigerant evaporator when a refrigerant compressor is switched from on to off. To provide air conditioners for air conditioning.

[0004]

In order to achieve the above object, the present invention employs the following technical means for each claim. In claim 1, as shown in FIG. 14, the refrigerant compressor 100 compresses and discharges the sucked refrigerant, and the air sent into the vehicle compartment by heat exchange with the refrigerant supplied by the operation of the refrigerant compressor 100. Refrigerant evaporator 110 for dehumidifying cooling
Refrigeration cycle 120 provided with the refrigerant evaporator 110
Evaporator temperature detecting means 130 for detecting the temperature of the glass, dew point temperature calculating means 140 for calculating the dew point temperature of the window glass of the vehicle, and the detected value of the evaporator temperature detecting means 130 and the glass dew point temperature calculating means 140 Comparison determination means 150 for comparing and calculating the calculated value, and when the comparison determination means 150 determines that the detection value of the evaporator temperature detection means 130 is larger than the calculation value of the glass dew point temperature calculation means 140, And control means 160 for operating the refrigerant compressor 100 so that the detection value of the evaporator temperature detection means 130 becomes smaller than the value calculated by the glass dew point temperature calculation means 140.

In the second aspect, as shown in FIG. 15, the refrigerant compressor 100 compresses and discharges the drawn refrigerant, and sends the refrigerant into the vehicle cabin by heat exchange with the refrigerant supplied by the operation of the refrigerant compressor 100. Refrigeration cycle 120 having a refrigerant evaporator 110 for dehumidifying and cooling the air to be discharged, and evaporator temperature detecting means 130 for detecting the temperature of the refrigerant evaporator 110
A glass dew point temperature calculating means 140 for calculating a dew point temperature of a window glass of a vehicle; and a compressor determining means for detecting an off state of the refrigerant compressor 100 after the on state of the refrigerant compressor 100 continues for a predetermined time. 170 and a comparison determining means 150 for comparing the detection value of the evaporator temperature detecting means 130 with the calculated value of the glass dew point calculating means 140.
And the refrigerant compressor 100
Is detected, and the comparing and judging means 150
When it is determined that the detected value of the evaporator temperature detecting means 130 is larger than the calculated value of the glass dew point temperature calculating means 140, the detected value of the evaporator temperature detecting means 130 is determined by the glass dew point temperature calculating means. And control means 160 for operating the refrigerant compressor 100 so as to be smaller than the calculated value of 140.

According to a third aspect, as shown in FIG. 16, the refrigerant compressor 100 compresses and discharges the drawn refrigerant, and sends the refrigerant into the vehicle cabin by heat exchange with the refrigerant supplied by the operation of the refrigerant compressor 100. Refrigeration cycle 120 having a refrigerant evaporator 110 for dehumidifying and cooling the air to be discharged, and evaporator temperature detecting means 130 for detecting the temperature of the refrigerant evaporator 110
A glass dew point temperature calculating means 140 for calculating the dew point temperature of the window glass of the vehicle, and an air outlet for determining whether or not the air outlet mode is a mode for opening a defroster air outlet for blowing air toward the window glass. Mode determination means 180,
A mode in which the defroster outlet is opened by the comparing and judging unit 150 and the outlet mode judging unit 180 for comparing the detected value of the evaporator temperature detecting unit 130 with the calculated value of the glass dew point temperature calculating unit 140. Is determined,
In addition, the detection value of the evaporator temperature detecting means 130 in the comparison judging means 150 is better than the glass dew point temperature calculating means 14.
If it is determined that the calculated value is larger than the calculated value of 0, the control means 160 for operating the refrigerant compressor 100 so that the detected value of the evaporator temperature detecting means 130 becomes smaller than the calculated value of the glass dew point temperature calculating means 140. And

According to a fourth aspect, as shown in FIG. 17, the refrigerant compressor 100 compresses and discharges the sucked refrigerant, and sends the refrigerant into the vehicle cabin by heat exchange with the refrigerant supplied by the operation of the refrigerant compressor 100. Refrigeration cycle 120 having a refrigerant evaporator 110 for dehumidifying and cooling the air to be discharged, and evaporator temperature detecting means 130 for detecting the temperature of the refrigerant evaporator 110
A glass dew point temperature calculating means 140 for calculating a dew point temperature of a window glass of a vehicle; and a compressor determining means for detecting an off state of the refrigerant compressor 100 after the on state of the refrigerant compressor 100 continues for a predetermined time. 170, an outlet mode determining means 180 for determining whether or not the outlet mode is a mode for opening a defroster outlet for blowing air toward the window glass, and a detection value of the evaporator temperature detecting means 130. An off state of the refrigerant compressor 100 is detected by the comparison determination means 150 and the compressor determination means 170, and a comparison is made by the blow-out port mode determination means 180. It is determined that there is a mode in which the defroster outlet is opened, and the detection value of the evaporator temperature detecting means 130 is compared with the value of the Dew point temperature when it is determined to be greater than the calculated value of the calculating means 140, the evaporator temperature detecting means detects values above the glass point temperature calculating means 140 of 130
And control means 160 for operating the refrigerant compressor 100 so as to be smaller than the calculated value.

[0008]

[Action and effect of the invention]

When the temperature of the refrigerant evaporator is determined to be higher than the dew point temperature of the window glass (in this case, the absolute humidity after passing through the refrigerant evaporator is lower than the absolute humidity in the vehicle interior). Is high, the refrigerant compressor is in the off state), the window glass may be fogged by the re-evaporation of the moisture condensed in the refrigerant evaporator, and the refrigerant compressor operates. Thereby, the air passing through the refrigerant evaporator is dehumidified and cooled, and the detected value of the evaporator temperature detecting means is smaller than the calculated value of the glass dew point calculating means, so that even when the blown air is blown to the window glass. No fogging occurs on the window glass.

[0009] (Vehicle air conditioner according to claim 2) If the refrigerant compressor is turned off after the on state has continued for a certain period of time, there is a high possibility that moisture condensed in the refrigerant evaporator will re-evaporate. . Therefore, in claim 2, when the refrigerant compressor is turned off after the ON state is continued for a certain period of time and the temperature of the refrigerant evaporator is determined to be higher than the dew point temperature of the window glass, the refrigerant compressor operates. It is. This allows
Even when the refrigerant compressor is switched from on to off and there is a high possibility that the water condensed in the refrigerant evaporator is likely to re-evaporate, operating the refrigerant compressor can prevent fogging of the window glass. it can.

[0010] (Vehicle air conditioner according to claim 3) When the blown air is blown toward the windowpane when the temperature of the refrigerant evaporator is higher than the dew point temperature of the windowpane, the windowpane may be fogged. high. Therefore, in claim 3, it is determined that the mode is an outlet mode (for example, a defroster mode, a foot differential mode, or the like) in which the blown air is blown toward the window glass, and that the temperature of the refrigerant evaporator is higher than the dew point temperature of the window glass. When it is performed, the refrigerant compressor operates. Therefore, when the blowout air is not in the outlet mode in which the blown air is blown toward the window glass (for example, in a foot mode, a face mode, and the like, except in the foot mode, where a small amount of air is blown out toward the window glass), When the blown air is not directly blown onto the window glass, the refrigerant compressor is not operated unnecessarily even when the temperature of the refrigerant evaporator is higher than the dew point temperature of the window glass.

According to a fourth aspect of the present invention, there is a high possibility that the refrigerant compressor is switched from on to off and moisture condensed in the refrigerant evaporator is re-evaporated, and the blown air is supplied to the window. When the refrigerant is blown toward the glass, the refrigerant compressor operates when it is determined that the temperature of the refrigerant evaporator is higher than the dew point temperature of the window glass. According to the fourth aspect of the present invention, when the temperature of the refrigerant evaporator is higher than the dew point of the window glass and the window glass may be fogged, there are two conditions for operating the refrigerant compressor (when the refrigerant compressor is turned on). By turning off after the state continues for a certain period of time, and in an outlet mode in which the blown air is blown out toward the window glass), it is possible to effectively prevent the window glass from fogging. Further, the refrigerant compressor can be operated only when there is a high possibility that the window glass is fogged by the above two determination conditions, so that the power saving effect is not significantly impaired.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a vehicle air conditioner according to the present invention will be described with reference to FIGS. FIG. 1 is an overall schematic diagram of a vehicle air conditioner. A vehicle air conditioner (hereinafter, referred to as an air conditioner) 1 of the present embodiment includes a duct 2 for guiding conditioned air into a vehicle interior, a blower 3 for introducing air into the duct 2 and sending the air into the vehicle interior, and a refrigeration unit constituting a cooling unit. A cycle 4, a hot water circuit 5 constituting heating means, and an air conditioner control device 6 (see FIG. 2) are provided.

The duct 2 has a branch duct 2a at its downstream end.
2c are connected, and the distal ends of the branch ducts 2a to 2c communicate with the outlets 7 to 9 that open into the vehicle interior. The outlets 7 to 9 are a defroster outlet 7 for blowing air toward the window glass 10 of the vehicle, a face outlet 8 for blowing air toward the upper body of the occupant, and a foot outlet 9 for blowing air toward the feet of the occupant. Is provided. These outlets 7 to 9 are selectively opened and closed by outlet switching dampers 11 and 12 provided at the upstream openings of the branch ducts 2a to 2c. Each of the outlet switching dampers 11 and 12 is driven by a driving unit such as a servo motor 13 (see FIG. 2) via a link mechanism (not shown).

The blower 3 comprises a blower case 3a, a centrifugal fan 3b, and a blower motor 3c, and the amount of air to be blown (the number of rotations of the blower motor 3c) is determined according to the voltage (blower voltage) applied to the blower motor 3c. A blower case 3a has an inside air inlet 1 for introducing vehicle interior air (inside air).
4 and an outside air inlet 15 for introducing outside air (outside air) are formed, and an inside air inlet 14 and an outside air inlet 15 are formed.
And an inside / outside air switching damper 16 that selectively opens and closes the internal and external air. The inside / outside air switching damper 16 is, for example, a servo motor 17 (see FIG. 2) via a link mechanism (not shown).
And the like.

The refrigeration cycle 4 is a cooling means for cooling the interior of the vehicle and a fogging removing means for removing fogging of the window glass, and includes a refrigerant compressor 18, a refrigerant condenser 19, a receiver 20, a pressure reducing device 21, a refrigerant evaporator. It is composed of functional components such as a heat exchanger 22 and an evaporating pressure regulating valve (hereinafter referred to as EPR) 23, and is connected in a ring shape by a refrigerant pipe 24 (FIG. 1).
reference).

The refrigerant compressor 18 is driven by a traveling engine 26 of the vehicle via an electromagnetic clutch 25, and compresses the sucked gas refrigerant to a high temperature and a high pressure and discharges it. The refrigerant condenser 19 receives the air from the cooling fan 27 and condenses and liquefies the high-temperature and high-pressure refrigerant discharged from the refrigerant compressor 18.

The receiver 20 separates the refrigerant sent from the refrigerant condenser 19 into gas and liquid, and flows out only the liquid refrigerant. The decompression device 21 decompresses and expands the liquid refrigerant guided from the receiver 20 and sends the refrigerant to the refrigerant evaporator 22. The refrigerant passing through the outlet pipe of the refrigerant evaporator 22 has a constant degree of superheat. It is a temperature-operated expansion valve that regulates the flow rate.

The refrigerant evaporator 22 is disposed in the duct 2 and evaporates the low-temperature and low-pressure refrigerant decompressed by the decompression device 21 by heat exchange with air sent from the blower 3. E
The PR 23 is provided between the refrigerant evaporator 22 and the refrigerant compressor 18 and maintains the evaporation pressure in the refrigerant evaporator 22 at a certain value or more (for example, 1.9 kg / cm ² ), thereby reducing the load when the heat load is low. The frost of the refrigerant evaporator 22 is prevented.

The hot water circuit 5 is heating means for heating the interior of the vehicle. The hot water circuit 5 is disposed downstream of the refrigerant evaporator 22 in the duct 2 and heats the air flowing through the duct 2 using the cooling water of the engine 26 as a heat source. And a hot water pipe 29 for connecting the heater core 28 to a cooling water circuit (not shown) of the engine 26 in an annular manner.

The heater core 28 is arranged in the duct 2 so as to form a bypass passage 30 in which the air passing through the refrigerant evaporator 22 flows around the heater core 28. The ratio between the amount of air passing through the heater core 28 and the amount of air passing through the bypass path 30 is adjusted by an air mix damper 31 arranged on the windward side of the heater core 28. The air mix damper 31 is driven by drive means such as a servo motor 32 (see FIG. 2) via a link mechanism (not shown).

The air conditioner control device 6 has a built-in microcomputer (not shown) in which a control program and various arithmetic expressions related to the air condition control are stored. As shown in FIG. ) Based on operation signals output from the servo motors 13 and 1 based on operation signals output from various sensors (described later).
7, 32, a motor drive circuit 34 for driving the blower motor 3c, and a clutch drive circuit 35 for driving the electromagnetic clutch 25.

The above-mentioned various sensors include an inside air temperature sensor 36 for detecting a vehicle interior temperature (inside air temperature Tr), an outside air temperature sensor 37 for detecting an outside air temperature (outside air temperature Tam), and a solar radiation amount (solar radiation amount Ts). A solar sensor 38, an air temperature sensor 39 (evaporator temperature detecting means) for detecting an air temperature (evaporated temperature Te) immediately after passing through the refrigerant evaporator 22, and a temperature (cooling water temperature Tw) of the engine cooling water. Water temperature sensor 40,
And a humidity sensor 41 for detecting the relative humidity (humidity Rh) in the passenger compartment.

The air conditioner operation panel 33 is disposed on an instrument panel (not shown) in the vehicle compartment, and as shown in FIG. 3, a temperature setting switch 42 for setting a desired interior temperature of the occupant, and this temperature setting switch 42. A set temperature display section 43 for digitally displaying the temperature set in the above, an auto switch 44 for outputting an automatic control command for the air conditioner 1, an off switch 45 for outputting an operation stop command for the air conditioner 1,
Inside / outside air changeover switch 46 for selecting the inlet mode, outlet changeover switch 47 for selecting the outlet mode, blower 3
And an air conditioner switch 49 for selecting ON / OFF of the electromagnetic clutch 25 are provided.

Next, the operation of this embodiment will be described. FIG. 4 is a flowchart showing a processing procedure of the air conditioner control device 6. First, various counters and flags are initialized and constants are set (step S1). Subsequently, the set temperature signal Tset of the temperature setting switch 42 and each sensor 3
6 to 41 (Tr, Tam, Ts, Te, Tw,
Rh) is read (steps S2, S3).

Subsequently, a target outlet temperature (hereinafter referred to as TAO) into the vehicle compartment is calculated according to the following equation (step S4: target outlet temperature calculating function).

[Equation 1] TAO = Kset · Tset−Kr · Tr−Kam ·
Tam−Ks · Ts−KRh · Rh + C Kset: temperature setting gain Kr: inside air temperature gain Kam: outside air temperature gain Ks: solar gain KRh: humidity gain C: correction constant.

Subsequently, the TAO calculated in step S4
, The blower voltage, the inlet mode, and the outlet mode are determined from the characteristic diagrams shown in FIGS. 5 to 7 (steps S5 to S7). The relationships shown in the characteristic diagrams of FIGS. 5 to 7 are stored in the microcomputer of the air conditioner control device 6 in advance.

Subsequently, the target opening degree SW of the air mix damper 31 is calculated according to the following equation so that the actual temperature of the air blown into the vehicle compartment becomes the TAO calculated in step S4 (step S8: target). Opening calculation function).

## EQU2 ## SW = [(TAO-Te) / (Tw-Te)]
× 100 (%)

Subsequently, the operation of the refrigerant compressor 18 is determined (step S9). The operation of the refrigerant compressor 18 is determined as follows.
The determination is performed based on the conditions required for ensuring the capacity necessary for air conditioning in the vehicle interior, comfort with respect to humidity, and anti-fog properties due to humidity. Hereinafter, the operation determination of the refrigerant compressor 18 will be described based on the flowchart shown in FIG.

First, it is determined based on the characteristic diagram shown in FIG. 9 whether or not it is necessary to turn on the refrigerant compressor 18 in order to secure the capacity required for air conditioning in the passenger compartment (step 9).
01). The horizontal axis of the characteristic diagram shown in FIG.
4 is the difference between the TAO calculated in step 4 and the temperature of the air introduced into the duct 2 (suction temperature Tin). Α on the horizontal axis is the temperature rise of the introduced air in the duct 2, and is a constant or a function of the vehicle speed. The suction temperature Tin may be detected using a sensor, or may be estimated from the suction port mode, the outside temperature Tam, the inside temperature Tr, and the like.

When it is determined in step 901 that the refrigerant compressor 18 is to be turned on, the flag is set to "1" (step 902), and the flag for turning on the refrigerant compressor 18 is turned on.
The mode is set (step 903). Step 901
When it is determined that the refrigerant compressor 18 is turned off, that is, when TAO is sufficiently higher than the suction temperature Tin, the relative humidity Rh in the vehicle cabin detected by the humidity sensor 41 and the internal air temperature detected by the internal air temperature sensor 36 are used. Absolute humidity H in the cabin from Tr
r is calculated (step 904, absolute humidity calculation function).

Subsequently, as the anti-fog judgment value for judging whether the window glass 10 is fogged or not, a wet air chart (prestored in a computer) shown in FIG. The saturation absolute humidity Hw is calculated from the inner surface temperature (dew point temperature of the inner surface of the window glass) Tg (step 9).
05 / judgment value calculation function). The inner surface temperature Tg of the window glass 10 is represented by a function (Equation 3) of the inner air temperature Tr, the outer air temperature Tam, and the vehicle speed V. Here, the inner air temperature Tg is simply referred to as the outer air temperature Tam.

Tg = f (Tr, Tam, V)

Subsequently, the absolute humidity Hr in the vehicle compartment calculated in step 904 and the saturation absolute humidity H as the anti-fog determination value are calculated.
w (Step 906, anti-fog determination function) to determine whether the window glass 10 is fogged or not. In this determination, when Hr−Hw ≧ β (determination of YES), it is necessary to turn on the refrigerant compressor 18 because the window glass 10 becomes cloudy, and the process proceeds to step 902.

At step 906, Hr-Hw <β
In the case of (NO determination), the process proceeds to step 907, where the vehicle interior humidity Rh (the value detected by the humidity sensor 41) is equal to the upper limit γ of the comfortable humidity (for example, the vehicle interior temperature is 25 ° C. and the relative humidity is 60%).
Is determined. In this determination, if Rh ≧ γ (determination of YES), it is necessary to turn on the refrigerant compressor 18 because the degree of occupant feeling uncomfortable is high, and the process proceeds to step 902.

At step 907, Rh <γ (NO
In step 908, it is determined whether or not the refrigerant compressor 18 has been turned on at least once since the ignition switch (not shown) was turned on. Specifically, it is determined whether or not the flag is “1”, and when the flag is “1” (YE
In the determination of S), it is determined that the refrigerant compressor 18 has been turned ON at least once, and when the flag is # 1, the determination is NO.
Is determined that the refrigerant compressor 18 has never been turned on.

If the refrigerant compressor 18 has been turned ON at least once (flag = 1), when the refrigerant compressor 18 is switched from ON to OFF, the window glass is re-evaporated by the water condensed in the refrigerant evaporator 22. 10 can be cloudy. Therefore, if the determination result of step 908 is YES, the post-evaporation temperature Te detected by the post-evaporation temperature sensor 39 is determined.
And the dew point temperature Tg on the inner surface of the window glass is compared and determined (step 909, comparison determination function). The dew point temperature Tg on the inner surface of the window glass is, as described above, the internal temperature Tr and the external temperature Tg.
am is calculated as a function of the vehicle speed V (glass dew point temperature calculation function).

In this determination, when Tg-Te ≧ 0 (YE
In the determination of S), the post-evaporation temperature Te is lower than the dew-point temperature Tg of the inner surface of the window glass, so that the window glass 10 does not fog. Therefore, it is not necessary to turn on the refrigerant compressor 18, and an OFF mode for turning off the refrigerant compressor 18 is set (step 910).

At step 909, Tg-Te <0
In the case of (determination of NO), the dew point temperature Tg of the inner surface of the window glass
Since the post-evaporation temperature Te is higher, the window glass 10 may be fogged. For this reason, even if it is determined in the anti-fog determination in step 906 that the window glass 10 is not fogged, it is necessary to turn on the refrigerant compressor 18.
Proceed to.

If it is determined in step 908 that the refrigerant compressor 18 has never been turned on (flag =
In 1), since the window glass 10 is determined not to fog in the anti-fog determination in step 906, the OFF mode is set in step 910 without executing the processing in step 909.

After the processing of step S9 is executed as described above, subsequently, control signals are sent to the servo motors 13, 17, 32, the motor drive circuit 34, and the clutch drive circuit 35 so that control target values are obtained. Output, the air outlet switching dampers 11 and 12, the inside / outside air switching damper 16, the air mix damper 31, the blower motor 3c, and the electromagnetic clutch 2
5 (Step S10, control function)

Subsequently, it is determined whether or not a predetermined control cycle τ has elapsed (step S11), and if it has elapsed (YES).
Is determined), the processing of step S2 and subsequent steps is repeated, and if not elapsed (determination of NO), step S11 is repeated until a predetermined control cycle τ elapses.

As described above, even if the window glass 10 is determined not to be fogged in the anti-fog determination in step 906, if the post-evaporation temperature Te (100% relative humidity) is higher than the dew point temperature Tg of the inner surface of the window glass, When the blown air is directly blown onto the window glass 10 or the like, the window glass 10 is likely to be fogged, so that the refrigerant compressor 18 is turned on and the refrigerant evaporator 2 is turned on.
By dehumidifying and cooling the air passing through 2, the fogging of the window glass 10 can be prevented.

In this embodiment, after the ignition switch is turned on in step 908, the refrigerant compressor 18
Is provided for determining whether or not has been turned ON even once. However, even if this processing is omitted, the effect of the present embodiment can be obtained.

Next, a second embodiment of the present invention will be described. FIG. 11 is a flowchart showing the operation of the second embodiment.
In the present embodiment, in the operation determination of the refrigerant compressor 18 described in the first embodiment (step S9), when the refrigerant compressor 18 is switched from ON to OFF, the ON time of the refrigerant compressor 18 continues for a predetermined time or more. In this case, the refrigerant compressor 18 is operated so that the post-evaporation temperature Te becomes lower than the dew point temperature Tg of the inner surface of the window glass. In the flowchart of FIG. 11, the same processes as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

If it is determined in steps 901, 906, 907, and 909 that the refrigerant compressor 18 needs to be turned on, the count of the timer built in the microcomputer is equal to or more than a predetermined value ε (a fixed time) ( That is, it is determined whether or not the ON state of the refrigerant compressor 18 has continued for a predetermined time or more (step 911: compressor determination function). If the determination is YES (not less than the predetermined value ε), the process proceeds to step 902, and if the determination is NO (the predetermined value ε)
(Less than), adds the count of the timer, sets the flag to '0' (step 912), and proceeds to step 903.

As described above, until the count of the timer becomes equal to or more than the predetermined value ε, the flag is set to “0” in step 912. Therefore, even if the refrigerant compressor 18 is switched from ON to OFF, step 908 (setting of the flag) is performed. The determination in step 909 is NO, and the processing in step 909 is not performed. That is, the process of step 909 is executed only when the refrigerant compressor 18 is turned off after the count of the timer becomes equal to or more than the predetermined value ε.

Thus, in the present embodiment, the refrigerant compressor 1
After the ON state of No. 8 has continued for a certain period of time,
F, that is, when there is a high possibility that the moisture condensed in the refrigerant evaporator 22 will re-evaporate, the refrigerant compressor 18
Is operated to make the post-evaporation temperature Te lower than the dew-point temperature Tg of the inner surface of the window glass, whereby the fogging of the window glass 10 can be prevented.

Next, a third embodiment of the present invention will be described. FIG. 12 is a flowchart showing the operation of the third embodiment.
In the present embodiment, in the operation determination of the refrigerant compressor 18 described in the first embodiment (Step S9), the determination of the outlet mode (Step 913, the outlet mode determination function of the present invention).
Is added. In addition, each process other than step 913 shown in the flowchart of FIG. 12 is the same as that of the first embodiment, and the same symbols are assigned and the description is omitted.

If the determination in step 908 is YES (if the refrigerant compressor has been turned on at least once since the ignition switch was turned on), the outlet mode is a mode in which the defroster outlet 7 is opened in step 913 (for example, , The defroster mode, the foot differential mode, or the foot mode in which the defroster outlet 7 is slightly opened. If the result of this determination is YES,
Proceeding to step 909, if the result of the determination is NO, step 910 is executed without executing step 909.
Set F mode.

As described above, when the blown air is directly blown onto the window glass 10 (that is, in a mode in which the defroster outlet 7 is opened), the refrigerant compressor is set so that the post-evaporation temperature Te becomes lower than the dew point temperature Tg of the inner surface of the window glass. By operating 18, the fogging of the window glass 10 due to the re-evaporation of the moisture condensed in the refrigerant evaporator 22 can be effectively prevented.

[Modification] In the operation determination of the refrigerant compressor 18 (step S9), the contents of the second embodiment and the contents of the third embodiment may be combined. That is, the refrigerant compressor 1
After the ON state of No. 8 has continued for a certain period of time,
F, when the outlet mode is the mode in which the defroster outlet 7 is opened, the refrigerant compressor 18 is operated such that the post-evaporation temperature Te becomes lower than the dew point temperature Tg of the inner surface of the window glass.
May be controlled to operate.

Although the present invention is applied to the air-mix type air conditioner 1, a reheat type air conditioner which controls the amount of cooling water supplied to the heater core 28 in accordance with the opening degree of a flow control valve provided in the hot water circuit 5 is described. May be applied. The flow control valve can adjust the valve opening by, for example, duty ratio control.

In this embodiment, the EPR type refrigeration cycle 4 having the EPR 23 installed between the refrigerant evaporator 22 and the refrigerant compressor 18 is used, but the ON / OFF control of the refrigerant compressor 18 via the electromagnetic clutch 25 is used. Refrigeration cycle, a variable capacity refrigeration cycle equipped with a variable capacity type refrigerant compressor, or the like.

In this embodiment, the absolute humidity Hr is calculated from the detection value of the humidity sensor 41 and the detection value of the inside air sensor 36. However, the relative humidity Rh detected by the humidity sensor 41 is changed to a fixed temperature (for example, 25 ° C.). The relative humidity may be converted into the relative humidity for control.

In this embodiment, the air temperature immediately after passing through the refrigerant evaporator 22 (post-evaporation temperature Te) detected by the post-evaporation temperature sensor 39 is used as the temperature of the refrigerant evaporator 22. The fin temperature or the value obtained by detecting the low pressure of the refrigeration cycle 4 and estimating the post-evaporation temperature may be used.

[Brief description of the drawings]

FIG. 1 is an overall schematic diagram of a vehicle air conditioner.

FIG. 2 is a block diagram related to a control system of the present embodiment.

FIG. 3 is a front view of an air conditioner operation panel.

FIG. 4 is a flowchart showing the operation of the present embodiment.

FIG. 5 is a control characteristic diagram of the blower.

FIG. 6 is a control characteristic diagram of the suction port mode.

FIG. 7 is a control characteristic diagram in an outlet mode.

FIG. 8 is a flowchart showing an operation determination of the refrigerant compressor.

FIG. 9 is a control characteristic diagram of the refrigerant compressor.

FIG. 10 is a psychrometric chart.

FIG. 11 is a flowchart showing the operation of the second embodiment.

FIG. 12 is a flowchart showing the operation of the third embodiment.

FIG. 13 is a graph showing a temperature change and a humidity change accompanying the operation of the refrigerant compressor.

FIG. 14 is a block diagram showing a configuration according to claim 1 of the present invention.

FIG. 15 is a block diagram showing a configuration according to claim 2 of the present invention.

FIG. 16 is a block diagram showing a configuration according to claim 3 of the present invention.

FIG. 17 is a block diagram showing a configuration according to claim 4 of the present invention.

[Explanation of symbols]

Reference Signs List 1 vehicle air conditioner 4 refrigeration cycle 6 air conditioner controller (absolute humidity calculation function, glass dew point temperature calculation function, judgment value calculation function, anti-fog judgment function, comparison judgment function, control function, compressor judgment function, outlet mode judgment Function) 7 Defroster outlet 10 Window glass 18 Refrigerant compressor 22 Refrigerant evaporator 39 Temperature sensor after evaporator (evaporator temperature detecting means)

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masafumi Kawashima 1-1-1, Showa-cho, Kariya-shi, Aichi Japan Inside Denso Co., Ltd. (72) Inventor Yuji 1-1-1, Showa-cho, Kariya-shi, Aichi Japan Japan Denso Stock In-company (72) Inventor Katsuhiko Samukawa 1-1-1 Showa-cho, Kariya-shi, Aichi Japan Inside Denso Co., Ltd. (56) References JP-A-60-176809 (JP, A) JP-A-2-99423 (JP, A JP-A-63-180514 (JP, A) JP-A-59-134006 (JP, A) JP-A-5-20904 (JP, U) JP-A-63-54507 (JP, U) Field (Int.Cl. ⁷ , DB name) B60H 1/32 623 B60H 3/00

Claims (4)

(57) [Claims] A) a refrigerant compressor that compresses and discharges the sucked refrigerant, and a refrigerant evaporator that dehumidifies and cools the air sent into the vehicle interior by heat exchange with the refrigerant supplied by the operation of the refrigerant compressor. B) evaporator temperature detecting means for detecting a temperature of the refrigerant evaporator; c) glass dew point temperature calculating means for calculating a dew point temperature of a window glass of a vehicle; Comparing and judging means for comparing the detected value of the means with the calculated value of the glass dew point calculating means; and e) the detected value of the evaporator temperature detecting means is more than that of the glass dew point calculating means. Control means for operating the refrigerant compressor such that the value detected by the evaporator temperature detecting means is smaller than the value calculated by the glass dew point temperature calculating means when it is determined that the calculated value is larger than the calculated value. Air conditioner. A) a refrigerant compressor for compressing and discharging the sucked refrigerant, and a refrigerant evaporator for dehumidifying and cooling air sent into the vehicle interior by heat exchange with the refrigerant supplied by the operation of the refrigerant compressor. A refrigerating cycle, b) evaporator temperature detecting means for detecting a temperature of the refrigerant evaporator, c) glass dew point temperature calculating means for calculating a dew point temperature of a window glass of a vehicle, and d) a temperature of the refrigerant compressor. After the ON state has continued for a certain period of time,
Compressor determination means for detecting an off state of the refrigerant compressor; e) comparison determination means for comparing a detection value of the evaporator temperature detection means with a calculation value of the glass dew point temperature calculation means; The off-state of the refrigerant compressor is detected by the compressor determination means, and the detection value of the evaporator temperature detection means is determined by the comparison determination means to be larger than the value calculated by the glass dew point temperature calculation means. In this case, the vehicle air conditioner includes control means for operating the refrigerant compressor such that the value detected by the evaporator temperature detecting means is smaller than the value calculated by the glass dew point calculating means. A) a refrigerant compressor which compresses and discharges the sucked refrigerant, and a refrigerant evaporator which dehumidifies and cools the air sent into the passenger compartment by heat exchange with the refrigerant supplied by the operation of the refrigerant compressor. B) an evaporator temperature detecting means for detecting a temperature of the refrigerant evaporator; c) a glass dew point temperature calculating means for calculating a dew point temperature of a vehicle window glass; and d) an outlet mode. Outlet mode determining means for determining whether or not the mode is a mode for opening a defroster outlet for blowing air toward the window glass; e) a detection value of the evaporator temperature detecting means and a calculation of the glass dew point temperature calculating means. Comparison determination means for comparing the value of the evaporator temperature with the value of the evaporator temperature detection means. When it is determined that the output value is larger than the calculated value of the glass dew point calculating means, the refrigerant compression is performed so that the detected value of the evaporator temperature detecting means is smaller than the calculated value of the glass dew point calculating means. A vehicle air conditioner comprising: control means for operating the machine. A) a refrigerant compressor for compressing and discharging the sucked refrigerant, and a refrigerant evaporator for dehumidifying and cooling air sent into the vehicle cabin by heat exchange with the refrigerant supplied by the operation of the refrigerant compressor. A refrigerating cycle, b) evaporator temperature detecting means for detecting a temperature of the refrigerant evaporator, c) glass dew point temperature calculating means for calculating a dew point temperature of a window glass of a vehicle, and d) a temperature of the refrigerant compressor. After the ON state has continued for a certain period of time,
Compressor determination means for detecting an off state of the refrigerant compressor; e) an outlet mode determination for determining whether an outlet mode is a mode for opening a defroster outlet for blowing air toward the window glass. F) comparison and determination means for comparing the detected value of the evaporator temperature detection means with the calculated value of the glass dew point temperature calculation means; and g) the compressor determination means determines that the refrigerant compressor is off. It is determined that the mode is the mode in which the defroster outlet is opened by the outlet mode determining means, and the detection value of the evaporator temperature detecting means is calculated by the comparison determining means by the glass dew point temperature calculating means. When it is determined that the value is larger than the value, the control means for operating the refrigerant compressor so that the detected value of the evaporator temperature detecting means is smaller than the calculated value of the glass dew point temperature calculating means. Vehicle air conditioner equipped with and.