JP2001121956A - Air conditioner for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner for a vehicle capable of restraining a temperature rise in a vehicle compartment immediately after the vehicle is stopped such as waiting until the traffic lights change. SOLUTION: On detecting a vehicle stop signal when the vehicle is stopped to wait until the traffic lights change, a compressor delay operation timer starts to count. The operation of an engine E and a compressor 11 is continued until the counting of the compressor delay operation time is completed after the vehicle is stopped, and a blowing fan 23 is turned off. Thus, the vapor pressure of a refrigerating cycle 1 is lowered so that the temperature of an evaporator 14 can be dropped. After the compressor delay operation, the blowing fan 23 is turned on, thereby blowing off the air heat-exchanged with the cooled evaporator 14 through a blowing duct into a vehicle compartment, so that the initial blow-off temperature after the vehicle stop can be lowered, and the time required for reaching the blow-off temperature which a passenger feels uncomfortable can be increased.

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 capable of air-conditioning the interior of a vehicle such as a large-sized route bus equipped with an automatic engine stop device.

[0002]

2. Description of the Related Art Conventionally, an air conditioner for a vehicle includes a blower fan driven by a drive motor, a refrigerant evaporator for exchanging heat of air blown into a passenger compartment with a refrigerant by the action of the blower fan, and cooling the refrigerant. The compressor includes a compressor driven by the engine to compress the refrigerant drawn from the refrigerant evaporator, and a refrigeration cycle having a refrigerant condenser for exchanging heat of the refrigerant discharged from the compressor with air to condense and liquefy.

[0003] In recent years, for example, in the case of a large-sized bus, for example, when a vehicle is stopped at a traffic light for the purpose of reducing noise when the vehicle stops, reducing exhaust gas (low pollution) and improving fuel economy (low fuel consumption). An idling stop and start system that automatically stops the engine every time it stops and restarts the engine when it starts
Restart device).

However, as shown in the time chart of FIG. 10, the engine and the electromagnetic clutch are turned off at the same time as the vehicle stop command is turned on to stop the compressor of the vehicle air conditioner. When the indoor temperature rises, there is a problem that passengers in the vehicle are uncomfortable while the vehicle is stopped. Therefore, as a conventional technique, as shown in a time chart of FIG. 10, there is a vehicle air conditioner configured to continuously operate only a blowing fan to blow air into a vehicle compartment even after the vehicle stops.

[0005]

However, in the above-described conventional technique, the refrigerant in the refrigerant evaporator evaporates and evaporates immediately after the vehicle stops, and the evaporator temperature rises immediately after the vehicle stops. In addition, since a sufficient amount of evaporated refrigerant is not held in the refrigerant evaporator, the evaporation temperature and the blowout temperature rise quickly. For this reason, the longer the vehicle stop time, the higher the temperature in the vehicle interior, which causes a problem that passenger discomfort increases. Alternatively, there is a problem that the driver does not use the above-described automatic engine stop / restart device because of concern about a rise in vehicle interior temperature.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a vehicle air conditioner capable of suppressing a rise in a vehicle interior temperature after a vehicle stops by lowering the temperature of a refrigerant evaporator immediately after the vehicle stops. .

[0007]

According to the first aspect of the present invention, the operation of the refrigerant compressor and the engine is continued until the condition for canceling the delayed compressor operation is satisfied after the vehicle stop signal is detected. In addition, the drive motor is controlled so as to reduce the rotation speed of the blower to a predetermined value or less. This allows the refrigerant compressor to continue to operate immediately after the vehicle stops, thereby lowering the evaporating pressure of the refrigeration cycle, thereby lowering the temperature of the refrigerant evaporator.

Accordingly, after the compressor delay operation, the air cooled by exchanging heat with the cooled refrigerant evaporator is blown into the passenger compartment by the operation of the blower.
The initial blowing temperature after the vehicle stops can be reduced. Therefore, it is possible to extend the time required to reach the blowing temperature at which the passenger feels uncomfortable, thereby suppressing the uncomfortable feeling of the passenger.

According to the second and third aspects of the present invention, when the condition for canceling the compressor delay operation is satisfied, the refrigerant compressor and the engine are automatically stopped, and the blower is operated or the rotation speed of the blower is set to a predetermined value. The drive motor is controlled so as to rise above the value. As a result, the refrigerant in the refrigerant evaporator evaporates and evaporates, and the temperature of the refrigerant evaporator rises.However, since the temperature of the refrigerant evaporator immediately after the vehicle stops is decreased, the refrigerant evaporator after the compressor delay operation is operated. The rise in temperature can be suppressed. Therefore, it is possible to extend the time required to reach the blowing temperature at which the passenger feels uncomfortable, thereby suppressing the uncomfortable feeling of the passenger.

According to the fourth aspect of the present invention, even if the flow rate of the refrigerant circulating in the refrigeration cycle is low, the expansion device can sufficiently secure the amount of the refrigerant supplied to the refrigerant evaporator. Is provided, a sufficient amount of refrigerant required for evaporation can be supplied to the refrigerant evaporator even after the vehicle stops. For this reason, it is possible to further reduce the temperature of the refrigerant evaporator and to suppress a rise in the vehicle interior temperature.

According to the invention described in claim 5, in the compressor delay operation in which the operation of the refrigerant compressor and the engine is continued after the vehicle stops, the compressor delay operation is performed after detecting the vehicle stop signal and starting the compressor delay operation. This is done until the time has elapsed. Alternatively, according to the invention described in claim 6, in the compressor delay operation in which the operation of the refrigerant compressor and the engine is continued after the vehicle stops, the evaporator is started after detecting the vehicle stop signal and starting the compressor delay operation. The process is performed until the temperature or the evaporator pressure becomes equal to or less than the set value.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on embodiments with reference to the drawings. FIGS. 1 to 6 show a first embodiment of the present invention. FIG. 1 is a diagram showing a refrigeration cycle of a vehicle air conditioner, and FIG. It is a figure showing an engine control device.

The vehicle air conditioner of this embodiment includes a refrigeration cycle 1 for air conditioning the interior of a vehicle such as a large route bus, and an air conditioner control device (hereinafter referred to as an air conditioner ECU) 2 comprising a microcomputer and the like. It is configured to be controlled by: In the vehicle of this embodiment, the engine E is automatically stopped when the vehicle stops (idling), such as at a traffic light, for the purpose of improving fuel efficiency when driving in an urban area with a high stopping rate. An idling stop and start system (automatic engine stop and restart device) that automatically restarts the engine E when the vehicle starts moving is provided.

The engine E includes an engine starting device (not shown) including a starting motor and an ignition device for starting or restarting the engine E, and a fuel injection device (not shown) for injecting fuel into the engine E. ) Is provided.
The engine starter is energized by an engine controller (not shown) 3 (not shown) to start the engine E when the occupant turns on the key switch, or when the ERS main switch is turned on. Restart the engine E.

The refrigeration cycle 1 includes a compressor 11, a condenser 12, a receiver (not shown), a throttle device 13, an evaporator 14, and the like. Of these, the compressor 11 is driven by the engine E,
This is a refrigerant compressor that compresses and discharges refrigerant sucked from the evaporator 14.

The compressor 11 has an engine E
An electromagnetic clutch 15 is connected as clutch means for interrupting transmission of rotational power from the compressor to the compressor 11. The V pulley 16 of the electromagnetic clutch 15 is drivingly connected to a V pulley 17 provided on the output shaft of the engine E via a V belt 19.

The condenser 12 is a refrigerant condenser that condenses and liquefies the refrigerant discharged from the compressor 11 by blowing air from the condenser fan 21. The condenser fan 21
Is a condenser blower that blows cooling air, which exchanges heat with the refrigerant in the condenser 12, to the condenser 12.
2 driven. Here, the condenser fan 21 may be mounted on the output shaft of the engine E and changed to a condenser (cooling) fan driven by the engine E.

As the throttle device 13, a variable throttle such as a temperature-operated expansion valve for reducing and expanding the refrigerant flowing from the receiver is used. The evaporator 14 is provided with the diaphragm device 1.
3 is a refrigerant evaporator that receives the air blown by an evaporator fan (hereinafter referred to as a blower fan) 23 and evaporates and vaporizes the refrigerant flowing in from 3.

The blower fan 23 is connected to the evaporator 1
An air-conditioning case (not shown) that exchanges heat with the refrigerant in 4
And a blower for an evaporator that blows air into the vehicle interior through a blower duct (not shown), and is driven by a drive motor 24. The ventilation duct is a ceiling duct having one or two outlets so that the air-conditioned air blows out for each seat.

The air conditioner ECU 2 is equivalent to the air conditioning control means of the present invention, and includes a well-known microcomputer including a CPU, a ROM, a RAM, and the like. Sensor signals from various sensors such as an air temperature sensor 4 and an air temperature sensor 5 for detecting the air temperature immediately after passing through the evaporator 14 (hereinafter referred to as “after-evaporation temperature”) are A / D converted by an input circuit (not shown). It is configured to be input to a microcomputer later.

The air conditioner ECU 2 is connected to an air conditioner (A / C) switch 6 for commanding cooling of the passenger compartment, a temperature setting device 7 as a temperature setting means for setting the passenger compartment temperature to a desired temperature, and the like. I have. The engine ECU 3 includes a main switch 8 of an idling stop / start system, a vehicle speed sensor 9 as a vehicle speed detecting unit for detecting a running speed (vehicle speed) of the vehicle, and a rotation as a rotation speed detecting unit for detecting a rotation speed of the engine E. The speed sensor 10, a lever position detecting means (not shown) for detecting the position of the shift lever, and the like are connected.

When the main switch 8 is turned on and the engine speed detected by the speed sensor 10 is the idling speed, the engine ECU 3 detects that the shift lever is at the N (neutral) position. And outputs a vehicle stop signal to the engine E and the air conditioner ECU 2.

The engine ECU 3 outputs a vehicle start signal to the engine E and the air conditioner ECU 2 when the shift lever detects the L (low) position or the D (drive) position while outputting the vehicle stop signal. . In addition,
The vehicle stop signal may be output when the traveling speed detected by the vehicle speed sensor 9 is equal to or lower than a predetermined speed (for example, 0 km / h), even if the engine rotation speed is not the idling rotation speed.

Next, a control method by the air conditioner ECU 2 of the vehicle air conditioner of this embodiment will be briefly described with reference to FIGS. Here, FIG. 3 is a flowchart showing the control operation when the vehicle stops.

First, switch signals from various switches,
Sensor signals from various sensors and a vehicle stop signal or a vehicle start signal from the engine ECU 3 are detected (step S).
1). Next, it is determined whether a vehicle stop signal is detected. That is, it is determined whether or not the vehicle stop command has been turned ON by detecting the vehicle stop signal (step S).
2). If the result of this determination is NO, normal air-conditioning operation is performed (step S3). Thereafter, the process proceeds to step S1.

If the result of the determination in step S2 is YES, the drive motor 24 of the blower fan 23 is turned off. Further, a compressor delay operation timer is started (step S4). Next, it is determined whether or not the count of the compressor delay operation timer has been completed. That is, the compressor delay operation time (predetermined time: for example, 5 seconds to 1
0 seconds) (step S)
5). If this determination is NO, the determination process of step S5 is repeated.

If the result of the determination in step S5 is YES, the drive motor 24 of the blower fan 23 is turned on,
The engine E is turned off. Further, the electromagnetic clutch 15 of the compressor 11 is turned off (step S6). Thereafter, the process exits the flowchart of FIG.

Here, the fan air volume of the blower fan 23 is
It is changed by changing the control voltage applied to the drive motor 24. The control voltage to the drive motor 24 is determined by the operation position of the air volume variable lever (switch) or the target blow temperature (TAO). Then, after the compressor delay operation, the drive motor 24 of the blower fan 23 is turned on.
In such a case, it is desirable to apply a control voltage to the drive motor 24, which is a fan air volume when the vehicle is running. May be changed.

[Operation of First Embodiment] Next, the operation of the vehicle air conditioner of this embodiment will be briefly described with reference to FIGS. Here, FIG. 4 is a time chart showing the control operation when the vehicle stops.

While the vehicle is running, the cycle operation of the refrigeration cycle 1 is performed by turning on the electromagnetic clutch 15 of the compressor 11 and the drive motor 24 of the blower fan 23. As a result, a sufficient amount of refrigerant required for evaporation can be supplied into the evaporator 14, so that the temperature of the air blown into the vehicle compartment decreases. Therefore, since the temperature in the vehicle compartment is lowered, the vehicle compartment is cooled.

Then, the vehicle stops due to waiting for a traffic light or the like,
When the rotation speed of the engine E reaches the idling rotation speed, that is, the engine E enters an idling state,
When the shift lever is operated to the N position, the engine ECU
3 outputs a vehicle stop signal. And air conditioner ECU
2 detects the vehicle stop signal and turns on the drive motor 24 to stop the operation of the blower fan 23 when the vehicle stop command is turned on.

At this time, the engine E and the electromagnetic clutch 15 are not turned off, and the engine E and the compressor 11 are not turned off.
Continue driving. In this case, it is desirable that the condenser fan 21 continue its operation, and in this embodiment, the condenser fan 2
The description 1 is omitted because it operates in synchronization with the operation of the compressor 11.

At the same time as the blower fan 23 is turned off, the compressor delay timer is started, and the counting of the compressor delay operation time after the vehicle stops is started. When the compressor delay operation timer completes counting for a predetermined time (for example, 5 seconds to 10 seconds), the compressor delay operation is released.

Therefore, the operation of the engine E and the compressor 11 is stopped by turning off the engine E and the electromagnetic clutch 15, and at the same time, the drive motor 24 is turned off.
By performing N, the blower fan 23 is operated. After that, air conditioning is performed only by blowing air. Thereby, after the compressor delay operation, the air that has exchanged heat with the evaporator 14 cooled during the compressor delay operation is blown into the vehicle interior through the air duct by the operation of the air blowing fan 23,
The outlet temperature after the vehicle stops is kept low.

[Effects of the First Embodiment] As described above, the vehicle air conditioner of this embodiment continues to operate the compressor 11 until a predetermined time elapses even after the vehicle stops, and during that time, the blower fan 23 Since the operation is stopped, the refrigeration cycle 1 during the compressor delay operation after the vehicle stops.
As shown in the time chart of FIG. 5, the temperature of the evaporator 14 (the temperature of the air immediately after passing through the evaporator 14 is the post-evaporation temperature) as shown in the time chart of FIG.
Goes down. Therefore, after the compressor delay operation, the air that has exchanged heat with the evaporator 14 cooled by the compressor delay operation is blown into the vehicle interior through the air duct by the operation of the blower fan 23, as shown in the time chart of FIG. In addition, the initial outlet temperature after the vehicle stops can be reduced.

After the compressor delay operation, the operation of the compressor 11 is stopped and the blower fan 23 is operated, so that the refrigerant in the evaporator 14 evaporates and evaporates, and the temperature of the evaporator 14 rises. Since the temperature of the evaporator 14 is lowered immediately after the vehicle stops, it is possible to suppress a rapid rise in the temperature of the evaporator 14. As a result, it is possible to extend the time required to reach the blowing temperature at which the passenger feels uncomfortable.

[Second Embodiment] FIGS. 5 to 8 show a second embodiment of the present invention, and FIG. 7 is a diagram showing the entire configuration of the diaphragm device. () Is a diagram showing a main configuration of the aperture device.

The expansion device of this embodiment uses a temperature-operated expansion valve 30 having the structure shown in FIG. The expansion valve 30 includes a valve body 31 constituting a valve case, a ball valve (valve element) 32 constituting a variable throttle valve together with the valve body 31, and a coil spring 33 for urging the ball valve 32 upward in the drawing. , An element 34 for driving the ball valve 32, and a temperature-sensitive cylinder 35 connected to the element 34
And

The valve body 31 is provided with a bubble sheet 38 provided in a partition that divides the internal space into a high-pressure channel 36 on the refrigerant inlet side and a low-pressure channel 37 on the refrigerant outlet side. . In addition, the high-pressure side flow path 36 is connected to an outlet of the receiver via a refrigerant pipe. In addition, the low pressure side flow path 3
Reference numeral 7 is connected to an inlet of the evaporator 14 via a refrigerant pipe.

In the hollow portion of the bubble sheet 38, a throttle hole 39 having an inner diameter smaller than that of the high-pressure channel 36 and the low-pressure channel 37 is provided. And in the valve body 31,
A bleed port 40 is provided as a flow path for bypassing a pressure reducing portion (valve portion) mainly composed of the ball valve 32 and the throttle hole 39. The bleed port 40
Is for ensuring a sufficient amount of refrigerant supplied into the evaporator 14 even when the ball valve 32 is in a closed state in which the ball valve 32 is seated on the bubble seat 38.

The ball valve 32 operates in the vertical direction together with a spring seat 45 abutting on an operating rod 44 connected to the diaphragm 41 in the element 34. The coil spring 33 has an upper end held by a spring seat 45 and a lower end held by an adjusting screw 46. Temperature sensing cylinder 35
Is for detecting the evaporation temperature at the outlet of the evaporator 14, and is connected to one side pressure chamber 48 of the element 34 through a capillary tube 47.

With the above configuration, for example, if the temperature inside the vehicle increases while a certain amount of refrigerant is flowing, the refrigerant evaporates and evaporates quickly, and the temperature at the outlet of the evaporator 14 increases. Therefore, the gas (refrigeration cycle 1)
Since the same gas refrigerant as the refrigerant charged in the inside expands (separates from the adsorbent that adsorbs gas), the diaphragm 4
1, the operating rod 44, the spring seat 45 and the ball valve 32 are lowered. As a result, the throttle hole 39 tends to be opened, so that the amount of refrigerant supplied to the evaporator 14 increases. When the temperature in the vehicle compartment decreases, the operation is reversed, and the amount of refrigerant supplied to the evaporator 14 decreases.

Here, FIG. 5 is a time chart showing the change of the post-evaporation temperature in the first and second embodiments and the prior art, and FIG. 6 is the change of the blowout temperature in the first and second embodiments and the prior art. 6 is a time chart showing the time chart shown in FIG. In FIGS. 5 and 6, the first embodiment is a case where the compressor delay operation is performed as described above, and the throttle device 13 is the same as that of the related art. The second embodiment is a case where the compressor delay operation is performed as described above, and the expansion device uses the expansion valve 30 with the bleed port 40.

As described above, in the vehicle air conditioner of this embodiment, by providing the bleed port 40 in a part of the valve body 31 of the expansion valve 30, the expansion valve 30 is temporarily provided after the vehicle stops.
Is in a valve closed state, that is, even if the ball valve 32 is seated on the bubble seat 38, a sufficient amount of refrigerant supplied into the evaporator 14 can be secured. For this reason, even after the vehicle is stopped, the amount of refrigerant required for evaporation can be supplied into the evaporator 14.

Therefore, as shown in the time charts of FIGS. 5 and 6, the temperature of the evaporator 14 can be reduced as compared with the first embodiment, and the rise in the temperature of the air blown into the vehicle compartment can be reduced by the first temperature. It can be suppressed more than the embodiment.

[Third Embodiment] FIG. 9 shows a third embodiment of the present invention and is a view showing a refrigeration cycle of an air conditioner for a vehicle.

The expansion device 13 of the present embodiment includes a first pressure reducing means 51 constituted by an expansion valve used when the vehicle is running.
And a second pressure reducing means 52 constituted by a fixed throttle such as a capillary tube or an orifice used when the vehicle stops.
And The sub second decompression unit 52 is provided in the middle of a bypass channel 53 that bypasses the first decompression unit 51. Note that an electronic expansion valve that can arbitrarily set the opening of the throttle valve may be used as the throttle device 13.

[Modification] In the present embodiment, an example in which the present invention is applied to an air conditioner (cooling device) for a vehicle such as a large-sized route bus has been described. The present invention may be applied to an air conditioner (cooling device) for a vehicle such as an automobile. Further, although the receiver cycle is used as the refrigeration cycle 1, an accumulator cycle or a heat pump cycle may be used.

In this embodiment, the cooling heat exchanger such as the evaporator 14 is installed in the air-conditioning case in which the airflow toward the vehicle compartment is generated by operating the blower fan 23. Both a heat exchanger and a heat exchanger for heating may be installed. Accordingly, the vehicle air conditioner can be used as a vehicle air conditioner and a vehicle dehumidifier.

In this embodiment, the drive motor 24 is controlled so that the operation of the blower fan 23 is stopped during the compressor delay operation after the vehicle stops, but the rotation of the blower fan 23 is controlled during the compressor delay operation after the vehicle stops. The drive motor 24 may be controlled so that the speed is reduced to a predetermined rotation speed (for example, a rotation speed at which the blowing amount becomes LOW) or less.

In this embodiment, the condition for canceling the compressor delay operation is set to a time when a predetermined time set in advance from the start of the count of the compressor delay operation timer has elapsed and the count is completed. The compressor delay operation is canceled when the temperature of the evaporator 14, the evaporator temperature or the evaporator pressure (low pressure of the refrigeration cycle 1) is detected to be equal to or less than the set value after the start of the compressor delay operation. Is also good.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a refrigeration cycle of a vehicle air conditioner (first embodiment).

FIG. 2 is a block diagram showing an air conditioner ECU and an engine ECU (first embodiment).

FIG. 3 is a flowchart showing a control operation when the vehicle is stopped (first embodiment).

FIG. 4 is a time chart showing a control operation when the vehicle is stopped (first embodiment).

FIG. 5 is a time chart (first and second embodiments) showing a change in the temperature of air blown out of the vehicle cabin.

FIG. 6 is a time chart showing changes in the temperature of the evaporator (first and second embodiments).

FIG. 7 is a cross-sectional view illustrating an entire configuration of a diaphragm device (second embodiment).

8A is a cross-sectional view showing a main configuration of a diaphragm device, and FIG. 8B is a cross-sectional view taken along line AA of FIG. 8A (second embodiment).

FIG. 9 is a configuration diagram showing a refrigeration cycle of a vehicle air conditioner (third embodiment).

FIG. 10 is a time chart showing a control operation when the vehicle is stopped (prior art).

[Explanation of symbols]

 E engine 1 refrigeration cycle 2 air conditioner ECU (air conditioning control means) 3 engine ECU 11 compressor (refrigerant compressor) 12 condenser (refrigerant condenser) 13 expansion device 14 evaporator (refrigerant evaporator) 23 blower fan

Claims (6)

[Claims] An air conditioner for a vehicle equipped with an automatic engine stop device for automatically stopping an engine when a vehicle stop signal output when the vehicle stops is provided. (A) The air conditioner is driven by the engine to compress refrigerant. A refrigeration cycle having a refrigerant compressor that discharges and discharges air, and a refrigerant evaporator that cools air by exchanging heat with air and refrigerant; and (b) driving the air cooled by the refrigerant evaporator driven by a drive motor. A blower that blows air into the vehicle interior; and (c) continues to operate the refrigerant compressor and the engine until the condition for canceling the compressor delay operation is satisfied after the detection of the vehicle stop signal, and An air conditioner for a vehicle, comprising: air conditioning control means for controlling the drive motor so that the rotation speed falls below a predetermined value. 2. The vehicle air conditioner according to claim 1, wherein said air conditioner control means automatically stops said refrigerant compressor and said engine when said condition for canceling said compressor delay operation is satisfied, and said air blower. An air conditioner for a vehicle, wherein the driving motor is controlled so as to drive the vehicle. 3. The vehicle air conditioner according to claim 1, wherein said air conditioning control means automatically stops said refrigerant compressor and said engine when said condition for canceling said compressor delayed operation is satisfied, and said blower An air conditioner for a vehicle, wherein the drive motor is controlled so that the rotation speed of the vehicle increases to a predetermined value or more. 4. The method according to claim 1, wherein:
The vehicle air conditioner according to any one of claims 1 to 3, wherein the refrigeration cycle includes a throttle device for supplying an appropriate amount of refrigerant to the refrigerant evaporator after detecting the vehicle stop signal. Air conditioner. 5. The method according to claim 1, wherein
In the air conditioner for a vehicle according to any one of the first to third aspects, the compressor delay operation for continuing the operation of the refrigerant compressor and the engine after the vehicle stops is performed for a predetermined time after the vehicle stop signal is detected and the compressor delay operation is started. The vehicle air conditioner is operated until the time elapses. 6. The method according to claim 1, wherein:
In the vehicle air conditioner according to any one of the first to third aspects, the compressor delay operation for continuing the operation of the refrigerant compressor and the engine after the vehicle stops is performed by detecting the vehicle stop signal and starting the compressor delay operation, and then starting the evaporator. An air conditioner for a vehicle, which is performed until the temperature or the evaporator pressure becomes equal to or lower than a set value.