JPH05131845A - Air conditioner for vehicle - Google Patents

Abstract

PURPOSE:To prevent the freezing of an evaporator without lowering an air- conditioning level by performing rapid cooling-down control in the case of the evaporator being in the dry state at the vehicle start time, and performing normal capacity control at the time of the evaporator being in the wet state. CONSTITUTION:At the vehicle starting initial time, whether or not the temperature of an evaporator is the specified value or more is judged by an evaporator state judging means 120. In the case of the temperature of the evaporator being the specified temperature or more, it is so judged that a thermal condition is high and the evaporator is normally in the dry state, so that rapid cooling- down control is executed. In the case of the temperature of the evaporator being the specified value or less, it is so judged that the thermal condition is low and the evaporator is normally in the wet state, so that rapid cooling- down control is made ineffective. In addition, outside temperature and vehicle interior temperature are added to the thermal condition which is the judgment factor of the evaporator state judging means 120.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a function of preventing freezing of an evaporator in a vehicle air conditioner having a rapid cool-down function which maximizes the capacity of a variable capacity compressor for a predetermined time at the beginning of driving the vehicle. The present invention relates to a rapid cooldown control device.

[0002]

2. Description of the Related Art A conventional rapid cool-down control device for an air conditioning system for a vehicle has a means for setting a target temperature of an evaporator, as disclosed in Japanese Patent Application Laid-Open No. 1-111517.
Means for detecting the actual temperature of the evaporator, and by setting the target temperature of the evaporator below the freezing temperature of the evaporator (for example, −10 ° C.), the difference between the target temperature of the evaporator and the actual temperature is usually set. The rapid cooldown control is performed by maximizing the compressor capacity determined by the above, and continuing this for a predetermined time (for example, 10 minutes) after the actual evaporator temperature becomes a predetermined value (for example, 3 ° C.) or less.

Further, in order to prevent this freezing, Japanese Patent Laid-Open No. 1-281515 discloses that the temperature of the evaporator is detected, and when the detected value is below a predetermined value for a predetermined time, the electromagnetic clutch is turned off. There is disclosed a device for stopping the operation of the cooling cycle to prevent the evaporator from freezing.

[0004]

However, when the vehicle is restarted immediately after the vehicle is stopped or after being stopped for a short time, the temperature of the evaporator does not rise sufficiently and the surface of the evaporator is condensed. Water droplets are accumulated, and if the rapid cooldown control is executed in this state, there is a problem that the evaporator freezes easily.To prevent further freezing, the operation of the cooling cycle was stopped. In this case, there was a problem that the air conditioning level would drop.

For this reason, according to the present invention, even when a request for the rapid cooldown control is started at the time of starting the vehicle, it is determined whether or not the quick cooldown control is to be performed depending on the state of the evaporator, and the evaporator is not lowered without decreasing the air conditioning level. An object of the present invention is to provide a vehicle air conditioner that prevents freezing.

[0006]

When the invention of claim 1 is explained with reference to FIG. 1, the heat load amount is predetermined in the vehicle air conditioner having at least the evaporator 7 for cooling the introduced air in the air conditioning duct 2. When it is larger than the value, the rapid cooldown start determination means 100 for requesting the transition to the rapid cooldown control, the evaporator temperature detection means 110 for detecting the temperature of the evaporator 7, and the evaporator temperature detection means 110 are detected. Evaporator state determination means 12 for determining whether the evaporator temperature is higher than a predetermined value or lower than the predetermined value.
0 and this evaporator state determination means 120
When it is determined that the evaporator temperature is higher than a predetermined value, the rapid cooldown control means 130 which validates the request for rapid cooldown by the rapid cooldown start determination means 100 and shifts to and executes the rapid cooldown control.
And when the evaporator state determination means 120 determines that the evaporator temperature is lower than a predetermined value,
The present invention comprises the normal control means 140 for invalidating the request for the rapid cooldown by the rapid cooldown start determination means 100 and shifting to the normal control and executing the normal control, and the invention of claim 2 will be described with reference to FIG. In a vehicle air conditioner having an evaporator 7 for cooling at least the introduced air in the air conditioning duct 2, a rapid cooldown start determination means 100 for requesting transition to the rapid cooldown control when the heat load amount is larger than a predetermined value. A heat load condition detecting means 150 for detecting a heat load condition including not only the evaporator temperature but also the temperature of intake air, and the heat load condition detected by the heat load condition detecting means 150 is higher than a predetermined value, Evaporator state determination means 120 for determining when it is lower than a predetermined value, and evaporator state determination means 12 When it is determined that the heat load condition is higher than a predetermined value, the rapid cooldown control means 130 which validates the rapid cooldown request by the rapid cooldown start determination means 100 and shifts to the rapid cooldown control and executes the rapid cooldown control. When the evaporator state determination means 120 determines that the heat load condition is lower than a predetermined value, the rapid cooldown start determination means 10
A normal control unit 140 that invalidates the request for rapid cooldown by 0 and shifts to the normal control and executes the normal control is provided.

[0007]

Therefore, according to the first aspect of the present invention, the temperature of the evaporator is detected by the evaporator temperature detecting means 110, and the evaporator state judging means 120 judges whether the evaporator temperature is equal to or higher than a predetermined value. When the evaporator state determination means 120 determines that the evaporator temperature is equal to or higher than the predetermined value, it is determined that the evaporator is often in a dry state due to high thermal conditions, and the rapid cooldown start determination is made. The rapid cooldown control means 130 executes the rapid cooldown control by validating the request for the rapid cooldown by the means 100, and the evaporator state determination means 1 described above.
When the evaporator temperature is determined to be equal to or lower than the predetermined value by 20, the restart is performed immediately after the vehicle is stopped or after being stopped for a short time, the thermal condition is low, and the evaporator 7 is often in a wet state. Then, since the normal control unit 140 performs the normal control by invalidating the request for the rapid cooldown from the rapid cooldown start determination unit 100, it is possible to prevent the evaporator from freezing when the vehicle is restarted, and the above-mentioned problem is achieved. It is possible.

Further, in the invention of claim 2, the heat load condition detecting means 150 detects the heat load conditions of the evaporator temperature and the intake air temperature, and the evaporator state judging means 120 detects the heat load condition of a predetermined value or more. It is determined whether or not. When the heat load condition is equal to or more than the predetermined value by the evaporator state determination means 120, it is determined that the heat condition is high and the evaporator is in a dry state in many cases, and the other heat load conditions are also added. Since it can be determined that there is no fear of freezing, the rapid cooldown control unit 130 executes the rapid cooldown control by validating the request for the rapid cooldown from the rapid cooldown start determination unit 100, and the evaporator state determination unit 120 performs the rapid cooldown control. If it is determined that the heat load condition is less than or equal to the predetermined value, it is determined that the thermal condition is low and the evaporator is often in a wet state, and there is a risk of freezing from other heat load conditions. In order to be able to make a determination, the normal control means 140 invalidates the rapid cooldown request from the rapid cooldown start determination means 100. Since the control of normal is performed, it is possible to prevent freezing of the evaporator, in which the object can be achieved.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

The vehicle air conditioner 1 shown in FIG.
Has an inside air introduction port 3, an outside air introduction port 4, and an inside air / outside air switching door (INTAKE door) 5 for appropriately selecting the inside air introduction port 3 or the outside air introduction port 4, on the most upstream side of the air conditioning duct 2. A blower 6 is provided on the downstream side. On the downstream side of the blower 6, a temperature adjusting means including an evaporator 7, an air mix door 13, and a heater core 11 is provided, and further on the most downstream side of the air conditioning duct 2, a differential air outlet 14 and a vent air outlet 15 are provided. , And the foot air outlet 16 are provided, and the mode doors 17a, 17b, 1
The openings are appropriately selected by 7c.

The evaporator 7 has a variable capacity mechanism 26.
A variable capacity compressor 8, a condenser, an expansion valve 10, and a cooling cycle. In this cooling cycle, the high-temperature and high-pressure gas refrigerant compressed by the variable capacity compressor 8 is transferred to the condenser 9 by the condenser 9.
When it radiates heat to the air passing through it, it is condensed and becomes a high-pressure liquid refrigerant, which is adiabatically expanded by the expansion valve 10 and becomes a mist-like refrigerant. This atomized refrigerant absorbs the heat of the air passing through the evaporator 7 in the evaporator 7 and evaporates to become a gas refrigerant. By repeating the heat absorbing action in the evaporator 7 and the heat radiating action in the condenser 9, the air passing through the evaporator 7 is cooled, and the cooling level changes depending on the amount of refrigerant discharged from the variable capacity compressor 8. ..

The variable displacement compressor 8 is of a wobble plate type, for example, and as shown in FIG. 4, a drive shaft 51 connected to a running engine (not shown) via an electromagnetic clutch 18 is inserted into a compressor body 8a. Was
The wobble plate 52 is attached to the hinge ball 5 on the drive shaft 51.
Connected through 3. This wobble plate 52
Is a crank chamber 54 formed in the compressor body 8a.
Is swingably supported on the drive shaft 51 about a hinge ball 53 as a fulcrum, and a piston 55 connected to the wobble plate 52 is connected to a cylinder bore 56 depending on a swing angle.
It is designed to reciprocate inside.

Further, the variable displacement compressor 8 is provided with a pressure control valve 57 so as to face the crank chamber 54. The pressure control valve 57 includes a valve body 59 for adjusting the communication between the crank chamber 54 and the suction chamber 58 communicating with the suction side, and a pressure responsive member 60 for moving the valve body 59 according to the pressure in the suction chamber 58. A solenoid 62 that moves the valve body 59 according to the amount of electric current I _SOL (capacitance variable signal) applied to the electromagnetic coil 59.
By controlling the amount of current I _SOL to the electromagnetic coil 61 from the outside, the piston 55 and the cylinder bore 56 are
The amount of blow-by gas that leaks into the crank chamber 54 from the interval is adjusted to the suction side.

A variable capacity mechanism 26 for changing the capacity of the variable capacity compressor 8 from the pressure control valve 57 and the like is constructed. In the capacity varying mechanism 26, the electromagnetic coil 61
When the amount of current I _SOL flowing through the solenoid 62 rises and the magnetic force of the solenoid 62 rises, the valve body 59 has a crank chamber 57 and a suction chamber 58.
A force acts in the direction of narrowing the communication with and the amount of blow-by gas leaking from the crank chamber 54 to the suction chamber 58 is reduced. Therefore, the pressure in the crank chamber 57 increases and the piston 5
The stroke of No. 5 is reduced, so that the discharge amount of the refrigerant is reduced.

Thus, by controlling the energization amount I _SOL from the outside, the refrigerant amount is controlled and the cooling capacity of the evaporator can be controlled.

Further, the heater core 11 of the vehicle air conditioner 1 is supplied with cooling water for a traveling engine (not shown) by opening the solenoid valve 12, thereby heating the passing air.

In the vehicle air conditioner 1 having the above structure,
The inside air or the outside air selected by the inside / outside air switching door 5 is blown to the downstream side of the air conditioning duct 2 by the blower 6. This air is cooled by passing through the evaporator 7, and is divided into air passing through the heater core 11 and air bypassing the heater core 11 depending on the opening degree of the air mix door 13. The air that has passed through the heater core 11 and is heated and the bypassed as-cooled air are mixed on the downstream side of the heater core 11,
The air whose temperature is adjusted to the desired temperature can be obtained. This temperature-controlled air is supplied to the mode doors 17a, 17b, 17
The temperature is adjusted in the vehicle interior by blowing out from the air outlets 14, 15, 16 selected by c into the vehicle interior.

In order to control the vehicle air conditioner 1, a microcomputer 19 is provided, and at least a temperature sensor 22 for detecting the outside air temperature, a temperature sensor 23 for detecting the temperature inside the vehicle, and a solar radiation for detecting the amount of solar radiation. Sensor 2
4, and a signal from a temperature sensor attached to the evaporator 7 (or a temperature sensor attached to the vicinity of the downstream side of the evaporator 7 for estimating the evaporator temperature) 25, a multiplexer (MPX) 20 and an A / D converter. Two
Signals from the operation panel 27, which will be described below, are input to the microcomputer 19.

The microcomputer 19 includes a central processing unit (CPU), a read-only memory (R) (not shown).
OM), a random access memory (RAM), an input / output port (I / O), etc., which are known per se and process the above-mentioned input signals according to a predetermined program and execute output circuits 37a to 37g. The control device controls the actuators 38a, 38b, 38c, the blower 6, the electromagnetic clutch 18, the variable capacity mechanism 26, and the electromagnetic valve 12, for example.

The operation panel 27 includes an AUTO switch 28 for automatically controlling the air conditioner, an A / C switch 29 for turning ON / OFF the operation of the cooling cycle, a DEF switch 30 for forcibly setting the blowout mode to the differential mode, and an air conditioner. Switch 32 for stopping the operation of the vehicle, a REC switch 31 for manually setting the intake air mode to inside air circulation (REC) or outside air introduction (FRE), up / down switches 33a and 33b for setting the temperature inside the vehicle, and a display section. 33c, a temperature setter 33, a MODE switch 34a for manually setting the blowing mode, and a display 34
b, a mode setting unit 34, a fan switch 35a for manually setting the air flow rate of the blower 6, and a display unit 3
The air volume setting device 35 is composed of 5b. The display units 33c, 34b, 35b are controlled by the microcomputer 19 via the display circuit 36.

A flow chart of an air conditioning control program executed by the microcomputer 19 will be shown below, and will be described in accordance with this flow chart.

The flow chart shown in FIG.
This is a main program executed by the microcomputer 19 in the automatic control mode of the air conditioner. This main program is started from step 200 by pressing the AUTO switch 28. In step 300, the set temperature Td, the vehicle compartment temperature Tr,
Outside temperature Ta, solar radiation Qs, and evaporator temperature Te
Is input as data.

From these data, the total signal T, which is a heat load signal, is calculated in step 400 by the following mathematical formula 1.

[0024]

[Equation 1] T = A / Tr + B / Ta + C / Te + D / Qs-E / Td + F

A, B, C, D and E are gain constants, and F is a correction term. These values are set by experiments to values that produce the optimum air conditioning effect.

Based on the total signal T calculated in step 400, the inside / outside air switching door position is changed to the inside air circulation mode (R) as shown in FIG. 6A in step 500.
EC) and the outside air introduction mode (FRE) are switched, and in step 600, the blower voltage of the blower 6 is set as shown in FIG. 6B. In addition, M of FIG.
AX HI indicates the maximum high speed operation of the blower 6, HI indicates high speed operation, and LOW indicates low speed operation.

In step 700, the air mix door 13 is controlled by the total signal T as shown in FIG. 6 (c), the following compressor control is performed in step 800, and further step 900 is performed.
6, the control of the mode doors 17a, 17b, 17c is performed as shown in FIG. 6 (d), and the above control is repeated thereafter.

6C, FC (full cool) indicates that the air mix door 13 is fully closed or close to it, and FH (full hot) indicates that the air mix door 13 is fully open or close to it. In addition, VENT (vent mode) in FIG. 6D shows a so-called upper blow mode in which the blow blows out only from the vent outlet 15, and HEAT (heat mode) shows a so-called lower blow mode in which only the foot blow outlet 16 blows out. , BI / L (bi-level mode) is an outlet switching signal T _F (T _F = Te + K ₁ Θ; K
₁ is a calculation constant, and Θ is the opening degree of the air mix door 13. ) Indicates a mode of linearly changing FC to FH.

The first aspect of the compressor control performed in step 800 is as shown in FIG. 7, in which various data are read in step 801 and an ignition switch (IG) (not shown) is turned on in step 802. It is determined whether or not the state has changed from OFF to ON. This determination is to determine whether or not the vehicle is in the initial stage of startup, and to determine one of the factors for performing the quick cooldown control.

If it is determined in step 802 that the ignition switch has changed from OFF to ON, the process proceeds to step 804, and the O
If the state is N, step 804 is bypassed and step 807 is proceeded to.

In step 804, it is determined whether the total signal T is 10 or more. This decision is
The heat load represented by the comprehensive signal T is for determining whether or not the heat load requires the rapid cooldown control, and it may be a heat load (10 or more) at a level for performing the quick cooldown control. For example, the process proceeds to step 805, and if not, the process proceeds to step 807.

In step 805, it is determined whether the evaporator temperature Te is lower than 20 ° C.
When the evaporator temperature Te is lower than 20 ° C., this determination is restarting immediately after the vehicle is stopped or restarted after a short stop, and the thermal condition is high and the evaporator 7 is in a wet state. We judge that there are many cases, and it is 20 ℃
In the above cases, it is determined that the thermal conditions are low and the evaporator 7 is in a dry state in many cases. Usually, in a heat load state where rapid cool-down control is required, the evaporator temperature is less than 20 ° C. means that the temperature of the evaporator 7 is sufficiently high by restarting the vehicle immediately after it is stopped or after restarting it for a short time. This is because it has not risen and it can be determined that the water droplets generated by dew condensation during cooling are attached to the surface of the evaporator.

In step 805, if the evaporator temperature Te is less than 20 ° C., step 80
7, the rapid cool-down control that may cause freezing is avoided, and if the temperature is 20 ° C. or higher, it can be determined that the evaporator 7 is in a dry state. Therefore, the process proceeds to step 806 and the rapid cool-down control is performed. The flag F is set to 1, and the routine proceeds to step 808, where the target evaporator temperature T'e is-
It is set to 10 ° C.

In step 807, it is determined whether or not the flag F of the rapid cooldown control is set to 1. If F = 1, the process proceeds to step 808, and if F ≠ 1, the process proceeds to step 808. Proceeding to 822, normal compressor capacity control is executed.

This compressor capacity control is based on the total signal T
6E, the capacity control signal (I _SOL ) value is proportional to the integral control (PI) by the difference ΔT between the evaporator outlet temperature T'e and the evaporator temperature Te.
Control). For this reason, setting the target outlet temperature T′e of the evaporator to −10 ° C. in step 808 means maximizing the capacity of the compressor. The lower limit value α of the target outlet temperature of the evaporator shown in FIG. 6 (e) is specifically 3 ° C., and the upper limit value β is 12 ° C. to 13 ° C.

After the control in step 822, the process returns to the main routine in step 823.

Further, in step 808, the target temperature T'e of the evaporator is set to -10 ° C. to maximize the compressor capacity, and then in step 810, the total signal T is a predetermined value or more (specifically, 3 or more). It is determined whether or not. In this determination, if the value of the total signal T is not a predetermined value, specifically, 3 or more, in order to indicate that the heat load has decreased, the process proceeds to step 818, and the flag F of the rapid cooldown control is set. Set 0, step 8
At 20, the target temperature T'e of the evaporator is -10 ° C.
From the above, the transition control is performed to gradually increase the value calculated by the total signal T, and the routine proceeds to step 822 to execute the normal capacity control.

In step 810, the total signal T
Is greater than or equal to the predetermined value 3, the process proceeds to step 812, where it is determined whether the evaporator temperature is 3 ° C. or lower. In this determination, if the evaporator temperature Te is 3 ° C. or less, the timer t for continuously operating the rapid cooldown control for 10 minutes is started in step 814,
In step 816, it is determined whether 10 minutes have elapsed.

When the evaporator temperature Te is 3 ° C. or more in step 812, the process bypasses step 814 and proceeds to step 816, and passes through steps 816 and 823 to return to the main routine. As a result, the start of the timer t is postponed until the evaporator temperature Te reaches 3 ° C.

In step 816, if the timer t has not elapsed for 10 minutes, the process returns from step 823 to the main routine to continue the rapid cooldown control.

If it is determined in step 816 that the timer t has timed out, step 818
In step 8, the flag F is set to 0 and the above step 8 is performed.
20 after executing the transfer control of step 20.
The normal capacity control is executed.

As described above, the rapid cooldown control is
State with maximum compressor capacity Step 808)
Then, is the evaporator temperature Te reduced to 3 ° C. or lower and continued for 10 minutes (step 812, step 814,
Step 816), or until the total signal T becomes a predetermined value (specifically, 3) or less (step 810), the vehicle of step 802 is set as an execution condition of the rapid cooldown control according to the present invention. The initial startup of
The total signal T in step 804 is not less than a predetermined value,
In other words, the heat load is equal to or higher than the predetermined value, and the evaporator temperature Te in step 805 is equal to or higher than the predetermined value. In other words, the thermal condition is high and the evaporator is in a dry state.

Further, as a feature of the invention of claim 1 as described above, when the evaporator temperature Te is below a predetermined value (specifically, 20 ° C.) at the initial stage of vehicle startup, the evaporator is in a wet state. Even if there is a request for rapid cooldown control due to other factors, execution of this rapid cooldown control is avoided and normal control is performed.

The difference between the invention of claim 2 and the invention of claim 1 in the flowchart according to the invention will be described below with reference to FIG. 8, in which the value of the total signal T is 10 or more in step 804. If it is determined that the heat load state for performing the rapid cooldown control is determined, step 851
Then, it is determined whether the evaporator temperature Te is 10 ° C. or lower.

In this determination, the evaporator temperature is 1
When the temperature is 0 ° C. or less, it is determined that the thermal condition of the evaporator 7 is low, and the step 82 is performed via the step 807.
2, the normal compressor capacity control is executed in step 822 as described above.

If it is determined in step 851 that the evaporator temperature is 10 ° C. or higher, step 85
In step 2, the mode of intake air is determined by the position of the inside / outside air switching door (INTAKE) 5.

In this determination, when the position of the inside / outside air switching door 5 is in the outside air introduction mode (FRE), it is determined in step 853 whether the outside air temperature Ta is 35 ° C. or higher. Further, in the determination of step 852, the position of the inside / outside air switching door 5 is set to the inside air circulation mode (REC).
If it is, in step 854, the vehicle interior temperature T
It is determined whether r is 33 ° C. or higher. In this determination, when the outside air or the inside air is equal to or higher than the predetermined value, it is determined that there is no risk of freezing of the evaporator, and therefore the rapid cooldown control of step 806 and thereafter is executed, and the outside air or the inside air is equal to or less than the predetermined value. If it is, it is determined that the temperature decrease rate of the evaporator is high,
The process proceeds to step 822 and shifts to normal control.

Thus, according to the second aspect of the present invention, it is determined whether or not the evaporator may be frozen depending on the temperature of the evaporator and the temperature of the intake air, so-called thermal conditions. In order to avoid the rapid cooldown control, it is possible to prevent the evaporator from freezing.

[0049]

As described above, according to the invention of claim 1, when the temperature of the evaporator is lower than a predetermined value at the initial stage of vehicle startup, the thermal condition is low and the evaporator is often in a wet state. By determining that the normal cool-down control is performed by avoiding the rapid cool-down control, it is possible to prevent the evaporator from freezing while maintaining the air conditioning level. Further, according to the invention of claim 2, the evaporator is prevented. If the temperature is lower than the specified value and the temperature of the intake air is lower than the specified value, it is determined that the thermal conditions are low and the evaporator is in a state where it is easy to freeze, and the rapid cool-down control is avoided to avoid normal cooling. Since the capacity is controlled, it is possible to prevent the evaporator from freezing while maintaining the air conditioning level.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing a configuration of a first invention.

FIG. 2 is a functional block diagram showing a configuration of a second invention.

FIG. 3 is a configuration explanatory view of a vehicle air conditioner according to an embodiment of the present invention.

FIG. 4 is a sectional view of a variable displacement compressor according to an embodiment of the present invention.

FIG. 5 is a flowchart of a main routine of air conditioning control executed by a microcomputer.

FIG. 6 is a timing chart showing a control state of each control device according to a comprehensive signal.

FIG. 7 is a flowchart of a compressor capacity control subroutine executed by a microcomputer according to the first aspect of the present invention.

FIG. 8 is a flowchart of a portion of the compressor capacity control subroutine according to the second invention which is executed by the microcomputer, which is different from the first invention.

[Explanation of symbols]

 2 Air-conditioning duct 7 Evaporator 100 Rapid cooldown start determination means 110 Evaporator temperature detection means 120 Evaporator state determination means 130 Rapid cooldown control means 140 Normal control means 150 Thermal load condition detection means

Claims (2)

[Claims] 1. In a vehicle air conditioner having an evaporator for cooling at least introduced air in an air conditioning duct, a rapid cooldown start determination requesting transition to a rapid cooldown control when a heat load amount is larger than a predetermined value. Means, an evaporator temperature detecting means for detecting the temperature of the evaporator, and an evaporator state determining means for determining whether the evaporator temperature detected by the evaporator temperature detecting means is higher than a predetermined value or lower than a predetermined value. When the evaporator state determination means determines that the evaporator temperature is higher than a predetermined value, the rapid cooldown control is validated by enabling the rapid cooldown request by the rapid cooldown start determination means, and the rapid cooldown is executed. Down control means and the evaporator state determination hand When the evaporator temperature is determined to be lower than a predetermined value, the normal cooler is provided, which invalidates the request for the rapid cooldown by the rapid cooldown start determining means, shifts to the normal control, and executes the normal control. A vehicle air conditioner. 2. In a vehicle air conditioner having an evaporator for cooling at least the introduced air in an air conditioning duct, a rapid cooldown start determination requesting transition to a rapid cooldown control when a heat load amount is larger than a predetermined value. Means, a heat load condition detecting means for detecting a heat load condition including not only the evaporator temperature but also the intake air temperature, and the heat load condition detected by the heat load condition detecting means is higher than a predetermined value, When the heat load condition is determined to be higher than a predetermined value by the evaporator state determination means that determines when the heat load condition is lower than a predetermined value, the rapid cooldown start determination means requests the rapid cooldown. And a rapid cool-down control means for executing and shifting to the rapid cool-down control. When the heat load condition is determined to be lower than a predetermined value by the heat condition determination means, the normal cooler means for invalidating the quick cooldown request by the rapid cooldown start determining means and shifting to normal control for execution. An air conditioner for a vehicle, comprising: