JP2002067659A - Air conditioner for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly heat inside a cabin even in a vehicle which is equipped with a high-efficiency diesel engine or the like. SOLUTION: When heating by a heater core 5 only is judged to be insufficient based on temperature of cooling water of an engine 22 which is detected by a water temperature detection means 25, a clutch 8 is connected and a compressor 7 is driven. After the first setting time is elapsed from the starting of the compressor 7, when the detected temperature by the water temperature detection means 25 is not increased to the set temperature, the compressor 7 is judged to be broken down, the clutch 8 is cut off, and that is displayed on a display means 27. When the heating by the heater core 5 only is judged to be sufficient, the clutch 8 is cut off.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle air conditioner.

[0002]

2. Description of the Related Art Conventionally, in a vehicle air conditioner, the interior of a vehicle can be heated by supplying engine cooling water to a heater core disposed in an air conditioning unit inside the vehicle.

[0003]

However, in recent high-efficiency diesel engines and the like, since the temperature of the engine itself is suppressed from increasing, the temperature of the engine cooling water cannot be so much expected. Therefore, the heater core cannot quickly heat the interior of the vehicle, especially immediately after the engine is started, and it is difficult to obtain a comfortable air-conditioning state at an early stage.

Accordingly, an object of the present invention is to provide a vehicle air conditioner capable of quickly heating the inside of a vehicle even if the vehicle is equipped with a high-efficiency diesel engine or the like.

[0005]

According to the present invention, there is provided a vehicle air conditioner having a heater core in which an engine cooling water flows in an air conditioning unit. Water temperature detection means for detecting temperature, a clutch for transmitting or interrupting power from the engine to a compressor, air flow detection means for detecting a blower air flow, and adjusting the flow rate of the heat exchange medium discharged from the compressor and the compressor. A first flow path in which a heat exchanger for exchanging heat between the heat exchange medium passing through the first flow rate adjustment means and the surrounding air is connected in a ring shape; (1) a second path in which the depressurizing means and the second flow rate adjusting means are connected in parallel, and a third flow rate adjusting means, a vehicle exterior heat exchanger and a second When performing a heating operation by closing the third flow rate adjusting means and performing a heating operation by closing the third flow rate adjusting means and a heat exchange medium circuit including a third path connected in parallel with the pressure reducing means, based on a cooling water temperature of the engine detected by the water temperature detecting means, If it is determined that the heating is insufficient with the heater core alone, the clutch is connected to drive the compressor, and after the first set time has elapsed from the start of the compressor, the temperature detected by the water temperature detecting means reaches the set temperature. If it does not rise, it is determined that the compressor is out of order and the clutch is disengaged and the display means is displayed on the display means. Means.

[0006] With this configuration, even when the temperature of the engine cooling water is low immediately after the start of the compressor, a sufficient amount of heat exchange medium is supplied to the heat exchanger inside the vehicle to start heating the vehicle interior early. Can be. Further, if the detected temperature of the water temperature detecting means does not rise to the set temperature after the first set time has elapsed from the start of the compressor, it is determined that a failure has occurred, such as the compressor not being driven. be able to.

[0007] Further, a detection means for detecting a discharge pressure or a discharge temperature from the compressor is provided, and the control means detects the pressure detected by the detection means after a lapse of a second set time from the first set time. If the pressure is equal to or lower than the set pressure, or if the temperature detected by the detection unit is equal to or higher than the set temperature, the heat exchange medium is collected as long as the compressor is driven, if the total flow rate adjustment unit is fully closed for the third set time It is preferable in that it is possible.

After the second set time has elapsed from the third set time, the control means may determine that the pressure detected by the detection means is equal to or lower than the set pressure, or that the temperature detected by the detection means is equal to the set temperature. In the above case, when it is determined that the compressor is out of order and the restart of the compressor is prohibited,
This is preferable in that a problem caused by a failure can be prevented.

The control means corrects at least one of the first to third set times, the set temperature, and the set pressure based on an outside air temperature, and further detects a vehicle speed. Wherein the control means corrects the first and second set times, the set temperature, and the set pressure based on the speed detected by the vehicle speed detecting means, or adjusts the first and second set times, the set temperature. It is preferable that at least one of the set pressures is corrected based on the blower air volume, because more accurate failure determination can be performed.

When the cooling operation is performed by opening the third flow rate adjusting means, the set temperature and the set pressure are increased and the second set time is shortened as compared with the case of performing the heating operation. However, it is preferable in that an appropriate failure determination can be made.

According to another aspect of the present invention, there is provided a vehicle air conditioner including a heater core in which an engine cooling water flows in an air conditioning unit.
Water temperature detecting means for detecting a cooling water temperature of the engine,
A clutch that transmits or disconnects power from the engine to a compressor, and the compressor, a flow rate adjusting unit that adjusts a heat exchange medium flow rate discharged from the compressor,
A heat exchange medium circuit comprising a heat exchanger for exchanging heat with the heat exchange medium and the surrounding air having passed through the flow rate adjusting means connected in a ring shape, and a depressurizing means connected in parallel to the flow rate adjusting means and the heat exchanger; If it is determined that heating is insufficient with only the heater core based on an auxiliary heater provided in the air conditioning unit and a cooling water temperature of the engine detected by the water temperature detecting means, the clutch is connected. Then, the compressor is driven, and if it is determined that the heating is insufficient even by driving the compressor, the auxiliary heater is energized, while if it is determined that the heater core alone is sufficient for heating, the clutch is disconnected. And control means for performing the control.

With this configuration, even if the temperature of the engine cooling water is low immediately after the start of the compressor, the auxiliary heater can be energized to heat the air passing directly through the air conditioning unit. Heating can be started.

According to the present invention, there is provided a vehicle air conditioner having a heater core in which an engine cooling water flows in an air conditioning unit as means for solving the above-mentioned problems.
Water temperature detecting means for detecting a cooling water temperature of the engine,
A clutch that transmits or interrupts power from the engine to a compressor, and the compressor, a flow rate adjusting unit that adjusts a heat exchange medium flow rate discharged from the compressor,
A heat exchange medium circuit comprising a heat exchanger for exchanging heat with the heat exchange medium and the surrounding air having passed through the flow rate adjusting means connected in a ring shape, and a depressurizing means connected in parallel to the flow rate adjusting means and the heat exchanger; If it is determined that heating is insufficient with only the heater core based on the auxiliary heater provided in the engine cooling water circuit and the engine cooling water temperature detected by the water temperature detecting means, the clutch is disengaged. When the connection is made to drive the compressor and it is determined that the heating is insufficient even by driving the compressor, the auxiliary heater is energized, while when it is determined that the heater core alone is sufficient for heating, the clutch is activated. Control means for shutting off.

With this configuration, even when the temperature of the engine cooling water is low immediately after the start of the compressor, the auxiliary heater is energized to heat the engine cooling water, and the heating by the heater core can be started at an early stage.

If the detected temperature of the water temperature detecting means does not rise to the set temperature after a first set time has elapsed from the start of the compressor, it is determined that the compressor has failed,
Disengage the clutch, display that effect on display means,
When the auxiliary heater provided in the engine cooling water circuit is energized, it is preferable that the auxiliary heater can compensate for the auxiliary heating even when the in-vehicle heat exchanger cannot perform the auxiliary heating.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic diagram of a vehicle air conditioner according to the present embodiment. In this air conditioner for a vehicle, a blower 2, a heat exchanger 3 inside a vehicle, an air mix damper 4, and a heater core 5 are provided in an air conditioning unit 1 inside the vehicle.
Are arranged.

The blower 2 is driven to rotate by the blower motor 6 to introduce outside air or inside air into the air conditioning unit 1.

The in-vehicle heat exchanger 3 is connected in the middle of a heat exchange medium circuit B in which a heat exchange medium is circulated by driving the compressor 7. The compressor 7 is driven by an engine 22 described later, and its driving force can be connected or disconnected by a clutch 8. In the heat exchange medium circuit B, the first path b1 to which the first capillary tube 9, the first flow rate control valve 10, and the muffler 11 are connected, and the second capillary tube 12 and the second flow rate control valve 13, are connected. 2nd route b2
And a third path b to which the third flow control valve 14, the vehicle exterior heat exchanger 15, and the third capillary tube 16 are connected
3 is comprised. A pressure detection sensor 17 and a temperature detection sensor 18 are provided near the discharge port of the compressor 7.
Is provided so that the pressure and temperature of the heat exchange medium discharged from the compressor 7 can be detected. The muffler 11 is for preventing the heat exchange medium that has passed through the first flow control valve 10 from generating abnormal noise in the vehicle interior heat exchanger 3. 19 and 20 are the first
A check valve and a second check valve, 21 is a compressor 7
This is an accumulator for preventing liquid from flowing into the accumulator.

The air mix damper 4 changes the rate at which the air heated or cooled by the heat exchanger 3 inside the vehicle is divided.
That is, by adjusting the amount of air heated by the heater core 5, it is used to adjust the temperature of air blown into the vehicle interior.

The heater core 5 is disposed in one of the flow paths divided by the air mix damper 4, and is provided with an engine 22.
Is connected to a circuit branched from a cooling water circuit A for cooling the cooling water by the radiator 23, so that the engine cooling water flows inside. A bypass passage a is connected in parallel to the radiator. The flow of the cooling water to the radiator 23 is allowed or blocked by the three-way valve 24. Further, the temperature of the cooling water flowing out of the engine 22 is detected by a water temperature detection sensor 25.

The connection and disconnection of the clutch 8 for driving and stopping the compressor 7, switching of the three-way valve 24, adjustment of the opening of the flow control valve 10, and the like are performed by detecting the temperature t detected by the water temperature detection sensor 25, The control is performed by the control device 26 based on the pressure p detected by the pressure detection sensor 17. Further, the control device 26 causes the failure display section 27 to display the failure status of the compressor 7 as described later.

Next, the drive control of the vehicle air conditioner by the control device 26 will be described with reference to the flowcharts of FIGS.

When the engine 22 is started and heating by the vehicle air conditioner is started (step S1), the temperature t detected by the water temperature detection sensor 25, that is, the compressor 7
Is read (step S2). And
It is determined whether the detected temperature t is higher than the first set temperature T1 (step S3). The first set temperature T1 is a maximum value (for example, 80 ° C.) that does not require cooling water to be radiated by the radiator 23 and cooled.

If the detected temperature t is higher than the first set temperature T1, it is necessary to cool the engine cooling water. Therefore, by switching the three-way valve 24, the water is passed through the radiator 23 and cooled (step S4). And clutch 8
And the driving of the compressor 7 is stopped (step S5).

On the other hand, if the detected temperature t is equal to or lower than the first set temperature T1, the three-way valve 24 is switched so that the cooling water does not flow through the radiator 23 (step S6). It is determined whether it is higher than T2 (step S7). The second set temperature T2 is determined by the heater core 5
Is set to the minimum value at which the air passing through the air conditioning unit 1 can be sufficiently heated.

If the detected temperature t is higher than the second set temperature T2, it is determined that the interior of the vehicle can be sufficiently heated only by the heater core 5, and the clutch 8 is disconnected and the driving of the compressor 7 is stopped as described above (step S8). ). On the other hand, if the detected temperature t is equal to or lower than the second set temperature T2, the heater core 5
Since the inside of the vehicle cannot be sufficiently heated depending on only the condition, the clutch 8 is connected and the compressor 7 is driven to start the auxiliary heating (step S9).

In the auxiliary heating, the heat exchange medium is cooled by the heat exchanger 3 on the inside of the vehicle. Therefore, a decrease in the discharge pressure from the compressor 7 cannot be prevented by adjusting the opening of the motor valve. To a value lower than the first set pressure P1 (for example, 8 kgf / cm2G). Therefore, the discharge pressure p from the compressor 7
Is read (step S10), and it is determined whether or not the detected pressure p is lower than the first set pressure P1 (step S10).
11) If the detected pressure p becomes lower than the first set pressure P1, the flow control valve 10 is closed (step S1).
2). As a result, the flow into the heat exchanger 3 on the inside of the vehicle is prevented, and the flow rate flowing back to the compressor 7 through the second capillary tube 12 increases. As a result, the operating condition of the compressor 7 is satisfied, and abnormal stop, failure, and the like are prevented.

During the start and stop of the series of auxiliary heating, the detected pressure p is changed to the second set pressure P2 (for example, 2
It is determined whether it is higher than 0 kgf / cm2G) (step S13). If the detected pressure p is higher than the second set pressure P2, it is determined that if driving in the compressor 7 is continued, there is a risk of failure, the power from the engine 22 is shut off by the clutch 8, and the compressor 7 is stopped. (Step S14). As a result, an unreasonable load is not applied to the engine 22, and the fuel consumption can be suppressed.

At this time, the opening of the flow control valve 10 is corrected upward (or fully opened) to promote the cooling of the heat exchange medium. That is, since the pressure (temperature) of the heat exchange medium is higher on the compressor 8 side than on the inside heat exchanger 3 side, the heat exchange medium flows into the inside heat exchanger 3 side from the compressor 8 side. In addition, there is a flow of air outside the inside heat exchanger 3 as long as the inside air conditioning is performed. Therefore, when the opening of the flow control valve 10 is upwardly corrected (or fully opened), heat radiation of the heat exchange medium is promoted, and its temperature and pressure are reduced at an early stage to return the compressor 7 until the operating conditions are satisfied. Becomes possible. For example,
An electromagnetic on-off valve was used as the flow control valve 10, and after the compressor 7 was stopped, changes in the pressure and temperature of the heat exchange medium were compared between when the electromagnetic on-off valve was closed and when it was opened. As a result, as shown in the graph of FIG. 6A, the stop time of the compressor 7 was able to be shortened by opening the electromagnetic on-off valve. FIG.
As shown in the graph of (b), since the driving time of the compressor 7 becomes long, it became possible to raise the blowing temperature early.

Thereafter, when the operation of the engine 22 is continued, the temperature of the engine 22 itself rises, and the water temperature detection sensor 25
, The three-way valve 24 is automatically switched in step 3 as described above.
The engine cooling water is cooled by the radiator 23 (Step S4).

In the auxiliary heating, a failure diagnosis of the compressor 7 is performed as follows (step S20).
That is, the flag F is set to 1 (step S21), and the temperature t detected by the water temperature detection sensor 25 and the pressure detection sensor 17
Is read, that is, the discharge temperature and the discharge pressure from the compressor 7 (steps S22 and S2).
3). Then, it is determined whether the detected temperature t is lower than the third set temperature T3 and whether the detected pressure p is higher than the third set pressure P3 (Steps S24 and S2).
5).

If both conditions in steps S24 and S25 are satisfied, the first flow control valve is opened (step S26), and after the first set time t1 has elapsed (step S27), the water temperature detection sensor 25 The detected engine coolant temperature te is read (step S28), and it is determined whether the detected temperature te is higher than the fourth set temperature T4 (step S29). If the detected temperature t is higher than the fourth set temperature T4, there is no problem in continuing the auxiliary heating by the in-vehicle heat exchanger 3, and the above-described steps are performed until the second set time t2 further elapses (step S32). After returning to S22 and repeating the above process, the process returns to normal heating. On the other hand, if the detected temperature t is equal to or lower than the fourth set temperature T4, it is determined that the temperature of the heat exchange medium does not rise so much because the compressor 7 does not operate sufficiently due to a failure, and a failure is displayed on the failure display unit 27 ( In step S30, the driving of the compressor 7 is stopped (step S30).
31), end the auxiliary heating.

At least one of the conditions when the detected temperature t is equal to or higher than the third set temperature T3 in the step S24, or when the detected pressure p is equal to or lower than the third set pressure P3 in the step S25. If satisfied, it is determined whether or not the flag F is 1 (step S33). If the flag F is 1, the total flow control valves 10, 13,
14 is closed (step S34), and after the third set time t3 has elapsed (step S35), the flag F is set to 0 (step S36). On the other hand, if the flag F is not 1, the step S22 is continued until the second set time t2 elapses.
And the process is repeated (step S37). Then, even if the second set time t2 has elapsed, the step S2
4. If both of the conditions in S25 are not satisfied, it is determined that the compressor 7 is out of order, and a fault indication is displayed on the fault display unit 27 (step S38), and the driving of the compressor 7 is stopped. (Step S39), and prohibits the restart (step S40).

As described above, according to the embodiment, since the failure diagnosis of the compressor 7 can be performed, the auxiliary heating is not continued with the compressor 7 having failed.

In the above embodiment, the third and fourth set temperatures T3 and T4, the fourth set pressure P4, and the first to third set times t1 to t3 are set according to the graphs shown in FIGS. It is preferable to change according to the temperature, the vehicle speed, and the blower air volume (however, the third set time t3 is only the outside air temperature).

In the above-described embodiment, the flow path is switched by the three-way valve 24. However, the flow of water not only to the radiator 23 but also to the heater core 5 may be stopped by appropriately providing an on-off valve or the like. Good.

Further, in the above-described embodiment, the description has been made of the interior heating of the vehicle. However, according to the vehicle air conditioner having the above configuration, the first and second flow control valves are closed to close the outside heat exchanger 15. To dissipate heat and use the in-vehicle heat exchanger 3 for cooling. In this case, it is necessary to increase the set temperature and the set pressure and to shorten the second set time t2 as compared with the above-described heating.

In the auxiliary heating, the air passing through the air conditioning unit 1 can be directly heated by an auxiliary heater disposed downstream of the heater core 5 in addition to the vehicle interior heat exchanger 3. Good. According to this, even if it is diagnosed that the compressor 7 has failed, auxiliary heating by the auxiliary heater is possible. Therefore, it is possible to heat the interior of the vehicle at the minimum required temperature. When the compressor 7 is out of order, it is preferable to increase the amount of electricity supplied to the auxiliary heater as compared with the case where the outage is not out of order.

The auxiliary heater may be provided in the middle of the engine cooling water circuit. According to this, the heating performance of the heater core 5 can be improved by assisting the heating of the engine cooling water, which is insufficient with the compressor 7 alone. However, even if the compressor 7 is diagnosed as having failed, auxiliary heating by the auxiliary heater is possible. Therefore, it is possible to heat the interior of the vehicle at the minimum required temperature. When the compressor 7 is out of order, it is preferable to increase the amount of electricity supplied to the auxiliary heater as compared with the case where the outage is not out of order.

[0040]

As is clear from the above description, according to the present invention, if it is determined that heating is insufficient with only the heater core, the clutch is connected to drive the compressor. Rather, by performing the auxiliary heating by the heat exchanger, the in-vehicle heating can be started early.

In particular, if the detected temperature of the water temperature detecting means does not rise to the set temperature after the elapse of the first set time from the start of the compressor, it is determined that the compressor is faulty. It is possible to make a determination, and there is no occurrence of an ancillary problem caused by driving with a failure.

Further, the entire flow rate adjusting means is fully closed until the third set time elapses, and thereafter, the driving of each flow rate adjusting means is controlled based on the pressure detected by the detecting means. After the exchange medium is collected, the compressor can be restarted appropriately and reasonably.

Further, after the second set time has elapsed from the restart of the compressor, if the pressure detected by the detecting means is lower than the set pressure, or if the temperature detected by the detecting means is higher than the set temperature, Since it is determined that the compressor has failed, accurate failure diagnosis can be performed.

Further, the first to third set times may be corrected based on the outside air temperature, or the first and second set times may be corrected.
Set temperature and set pressure are detected speed by vehicle speed detection means,
Since the correction is made based on the blower air volume, a more accurate failure diagnosis can be performed.

Further, an auxiliary heater is provided in the air conditioning unit or in the engine cooling water circuit, and when the heating by the heater core alone is insufficient, the heater is energized. it can.

In particular, since the auxiliary heater in the air conditioning unit and the engine cooling water circuit is energized at the time of failure diagnosis of the compressor, even if heating by the heat exchanger inside the vehicle cannot be performed, it is supplemented to the necessary minimum. Heating performance can be ensured.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a vehicle air conditioner according to an embodiment.

FIG. 2 is a flowchart illustrating air conditioning control by the control device of FIG. 1;

FIG. 3 is a flowchart illustrating air conditioning control by the control device of FIG. 1;

FIG. 4 is a flowchart showing air conditioning control by the control device of FIG. 1;

FIG. 5 is a flowchart showing air conditioning control by the control device of FIG. 1;

6 is a graph showing a change in pressure (a) and a change in temperature (b) of the heat exchange medium when the flow control valve of FIG. 1 is opened or closed.

FIG. 7 shows an outside air temperature, third and fourth set temperatures T3 and T4, a fourth set pressure P4, first to third set times t1 to t.
6 is a graph showing each relationship with No. 3;

FIG. 8 shows vehicle speed, third and fourth set temperatures T3 and T
It is a graph which shows each relationship with 4th, 4th set pressure P4, and 1st and 2nd set time t1 and t2.

FIG. 9 shows the blower air volume, third and fourth set temperatures T3 and T4, fourth set pressure P4, first and second set times t1.
6 is a graph showing the relationship between the values and t2.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Air-conditioning unit 2 ... Blower 3 ... Heat exchanger inside a car 4 ... Air mix damper 5 ... Heater core 6 ... Blower motor 7 ... Compressor 8 ... Clutch 9 ... 1st capillary tube 10 ... 1st flow control valve 11 ... Muffler 12 ... 2nd 2 capillary tube 13 ... second flow control valve 14 ... third flow control valve 15 ... outside heat exchanger 16 ... third capillary tube 17 ... pressure detection sensor 18 ... temperature detection sensor 22 ... engine 23 ... radiator 24 ... three-way valve 25 water temperature detection sensor 26 control device 27 failure display

Claims (10)

[Claims] 1. A vehicle air conditioner having a heater core in which an engine cooling water flows in an air conditioning unit, wherein a water temperature detecting means for detecting a temperature of the engine cooling water, and a power from the engine to a compressor. Or a clutch to be shut off, an air flow detecting means for detecting a blower air flow, the compressor, a first flow adjusting means for adjusting a flow rate of a heat exchange medium discharged from the compressor, and a heat exchange passing through the first flow adjusting means. A first path in which a heat exchanger for exchanging heat between the medium and the surrounding air is connected in a ring shape, a second path in which a first pressure reducing means and a second flow rate adjusting means are connected in parallel to the flow rate adjusting means and the heat exchanger, A heat exchange medium circuit including a third path in which a third flow rate adjustment means, an exterior heat exchanger, and a second pressure reduction means are connected in parallel to the flow rate adjustment means and the heat exchanger; When performing the heating operation with the third flow rate adjusting means closed, if it is determined that the heating is insufficient with only the heater core based on the cooling water temperature of the engine detected by the water temperature detecting means, the clutch is connected. If the temperature detected by the water temperature detecting means does not rise to the set temperature after the first set time has elapsed from the start of the compressor, it is determined that the compressor is malfunctioning, and the clutch is disconnected. If, on the other hand, this is displayed on the display means, and it is determined that heating only with the heater core is sufficient,
A vehicle air conditioner comprising: a control unit that disconnects the clutch. 2. The apparatus further comprises a detecting unit for detecting a discharge pressure or a discharge temperature from the compressor, wherein the control unit detects the discharge pressure or the discharge temperature after the second set time has elapsed from the first set time. 2. The method according to claim 1, wherein when the detected pressure is equal to or lower than a set pressure, or when the temperature detected by the detecting unit is equal to or higher than the set temperature, the total flow rate adjusting unit is fully closed for a third set time. Vehicle air conditioners. 3. The control means, when a pressure detected by the detection means is equal to or less than a set pressure after a lapse of a second set time from the third set time, or when a temperature detected by the detection means is equal to or more than the set temperature The vehicle air conditioner according to claim 2, wherein in the case of (1), it is determined that the compressor is out of order and restart of the compressor is prohibited. 4. The apparatus according to claim 1, wherein the control unit corrects at least one of the first to third set times, the set temperature, and the set pressure based on an outside air temperature. 4. The vehicle air conditioner according to any one of items 3. 5. A vehicle speed detecting means for detecting a vehicle speed, wherein the control means corrects the first and second set times, the set temperature, and the set pressure based on the speed detected by the vehicle speed detecting means. The vehicle air conditioner according to any one of claims 1 to 4, wherein: 6. The control device according to claim 1, wherein the control unit corrects at least one of the first and second set times, the set temperature, and the set pressure based on a blower air volume. The vehicle air conditioner according to any one of claims 4 to 7. 7. When the cooling operation is performed by opening the third flow rate adjusting means, the set temperature and the set pressure are increased and the second set time is shortened as compared with the case of performing the heating operation. The vehicle air conditioner according to any one of claims 1 to 4, wherein 8. A vehicle air conditioner provided with a heater core in which an engine cooling water flows in an air conditioning unit, wherein a water temperature detecting means for detecting a temperature of the cooling water of the engine, and a power from the engine is transmitted to a compressor. Or a clutch for shutting off, the compressor, a flow rate adjusting means for adjusting the flow rate of the heat exchange medium discharged from the compressor, and a heat exchanger for exchanging heat between the heat exchange medium passing through the flow rate adjusting means and the surrounding air. And a heat exchange medium circuit in which a pressure reducing means is connected in parallel to the flow rate adjusting means and the heat exchanger; an auxiliary heater disposed in the air conditioning unit; and an engine detected by the water temperature detecting means. If it is determined based on the cooling water temperature that the heating is insufficient with the heater core alone, the clutch is connected to drive the compressor, and the Control means for energizing the auxiliary heater if it is determined that heating is insufficient even by driving the impreza, and disengaging the clutch if it is determined that heating is sufficient only with the heater core. A vehicle air conditioner characterized by the above-mentioned. 9. A vehicle air conditioner having a heater core in which an engine cooling water flows in an air conditioning unit, wherein a water temperature detecting means for detecting a temperature of the cooling water of the engine, and transmitting power from the engine to a compressor. Or a clutch for shutting off, the compressor, a flow rate adjusting means for adjusting the flow rate of the heat exchange medium discharged from the compressor, and a heat exchanger for exchanging heat between the heat exchange medium passing through the flow rate adjusting means and the surrounding air. A heat exchange medium circuit in which pressure reducing means is connected in parallel with the flow rate adjusting means and the heat exchanger; an auxiliary heater disposed in an engine cooling water circuit; and an engine detected by the water temperature detecting means. Based on the cooling water temperature, if it is determined that heating is insufficient with only the heater core, the clutch is connected to drive the compressor, Control means for energizing the auxiliary heater if it is determined that heating is insufficient even by driving the compressor, and disconnecting the clutch if it is determined that heating is sufficient only with the heater core. A vehicle air conditioner characterized by the above-mentioned. 10. If the temperature detected by the water temperature detecting means does not rise to the set temperature after a lapse of a first set time from the start of the compressor, it is determined that the compressor is out of order and the clutch is disconnected. 9. The air conditioner for a vehicle according to claim 8, wherein a display means is displayed on the display means, and the auxiliary heater is energized.