JPH0516648A - Vehicle air conditioner - Google Patents

Abstract

PURPOSE:To switch warm-up control to steady control at optimum timing without using a water temperature sensor. CONSTITUTION:During warm-up control wherein lower portion blowout temperature is considerably low as compared to target blowout temperature, the quantity of air blown by a blower is set to a quantity V1 of air suitable for the warm-up control. When the difference between the target blowout temperature and the lower portion blowout temperature is reduced and a quantity V2 of air suitable for steady control becomes smaller than the quantity V1 of air suitable for the warm-up control, the quantity of air blown by the blower is set to V2. The quantities V1, V2 of air are compared with each other and the smaller is selected whereby the warm-up control can be switched to the steady control at optimum timing without using a water temperature sensor.

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 for performing warm-up control.

[0002]

2. Description of the Related Art When a vehicle is started in cold weather such as winter, the vehicle compartment, engine cooling water, etc. are in a considerably cold state. In such a case, if the air mix mode is set to max hot and the air volume is maximized, cold air will be blown and the passengers will feel cold. As a control to avoid such a problem, when the engine cooling water is not sufficiently warm, the amount of air blown into the vehicle interior is reduced to reduce unpleasant cold air generated by blowing cold air, So-called warm-up control is known.

As a method of measuring the engine cooling water temperature, which is an important parameter for performing warm-up control, there is a method of directly measuring the engine cooling water temperature with a water temperature sensor (Japanese Patent Laid-Open No. 2-57419).
However, recently, a blow-out temperature sensor is used in order to accurately detect the temperature of blown air blown into the vehicle interior, and there is an increasing demand for an air conditioner capable of performing warm-up control.

Therefore, in order to reduce the cost, an air conditioner has been devised which performs warm-up control using a blow-out temperature sensor instead of a water temperature sensor. It is disclosed in Japanese Patent No. 233112.

According to this conventional technique, when it is determined that the warm-up control is to be performed, when the blow-out temperature detected by the blow-out temperature sensor provided in the ventilation duct is lower than a predetermined temperature, that is, the air blown into the vehicle interior When the temperature is low, the amount of blown air is reduced until the blowout temperature reaches a predetermined temperature, and when the temperature becomes equal to or higher than the predetermined temperature, the normal airflow rate control is resumed so that the occupant does not feel uncomfortable.

[0006]

As in the above-mentioned prior art, if the timing of returning from the warm-up control in the transition period to the air volume control in the stationary period is set when the blowout temperature reaches a certain fixed value, Excess or deficiency occurs in warm-up depending on the magnitude of disturbance such as outside temperature.

For example, when the outside air temperature is considerably low, the warm-up control is additionally performed because the blow-out temperature remains lower even if the engine cooling water is sufficiently warmed. As a result, noise may be generated due to the fact that the amount of air blown into the vehicle interior continues to be long. Further, when the outside air temperature is relatively high, the blow-out temperature may reach a predetermined temperature even if the engine cooling water is not warmed to a steady state, and the warm-up control may be insufficient and the passenger may feel cold. Also, when the warm-up control is switched to the steady control, the air volume changes, which causes strangeness.

Therefore, the present invention was devised to solve the above-mentioned problems, and without using a water temperature sensor,
Moreover, it is an object of the present invention to provide a vehicle air conditioner capable of switching from warm-up control to steady-state air volume control at optimum timing.

[0009]

In order to achieve the above object, the present invention, as shown in FIG. 10, includes a blower 19 for generating an air flow in a ventilation duct 20 and a temperature control for adjusting the temperature of the air flow. Means 21 and a blow-out temperature detecting means 9 installed in the ventilation duct 20 for detecting the blow-out temperature of the air flow whose temperature is adjusted by the temperature adjusting means 21;
A warm-up determination unit M2 that determines whether warm-up control should be performed based on a predetermined condition and outputs a warm-up determination result, an outside air temperature detection unit 2 that detects at least the outside air temperature, and a vehicle room temperature that detects the vehicle interior temperature. Temperature information that blows out into the vehicle interior is calculated based on signals from the detection means 1 and the vehicle room temperature setting means 10 that sets the target set temperature in the vehicle interior, and the temperature at which the temperature adjusting means 21 is controlled based on the temperature information. An air conditioner for a vehicle comprising: an information calculation means M1; and an air volume control means M6 that outputs a control signal for controlling the blower 19 based on the temperature information, the blowout temperature, and the warm-up determination result. The air volume control means M6 calculates a first air volume signal to be blown by the blower 19 based on the blowout temperature, and a first air volume calculation means M3; Second flow rate calculating means M for the blower 19 for calculating a second flow rate signal to be blown based on the time information
4, the first air volume signal, the second air volume signal, and the warm-up determination result are input, and the first air-volume signal is selected when the warm-up determination result determines that the warm-up should be performed. Then, the first air volume signal and the second air volume signal are compared, and when the first air volume signal and the second air volume signal are close to each other, the second air volume signal is selected instead of the first air volume signal. The gist of the present invention is a vehicle air-conditioning system configured with the air volume selection means M5.

[0010]

The first air volume signal calculated by the first air volume calculating means is based on the blowout temperature detected by the blowout temperature detecting means.
That is, the first air volume signal is a signal that reflects the temperature adjustment capability of the temperature adjustment means, for example, the degree of increase in engine cooling water temperature, and is also a signal that is influenced by the outside air temperature and the like. Therefore, it can be said that the first air volume signal is an air volume signal suitable for being adopted during the warm-up control.

On the other hand, the second air volume signal calculated by the second air volume calculation means is based on the temperature information calculated by the temperature information calculation means. In other words, the second air volume signal does not indicate the air volume signal in the transition period such as during warm-up control, but is the original air volume signal suitable for the control in the stationary period.

In the present invention, the air volume selection means always compares the first and second air volume signals to select the optimum air volume. Specifically, the first air volume signal is selected when it is determined that the air should be warmed up, and the second air volume signal is selected instead of the first air volume signal when both air volume signals are close to each other.

The above-mentioned approaching is when the air volume blown by the blower does not actually change even if the first air volume signal is switched to the second air volume signal. It is also time to end the warm-up control as a result of the engine coolant temperature etc. having risen considerably.

Therefore, according to the present invention, by switching from the warm-up control to the steady control when the above-mentioned approach is made, there is no change in the air volume at the time of switching, and neither excessive nor insufficient warm-up occurs.

[0015]

As described above, according to the present invention, it is possible to blow out an air flow suitable for the warm-up control without using the water temperature sensor. Also, since it is possible to switch from warm-up control to steady-state control without excess or deficiency of warm-up, it is possible to prevent problems such as long warm-up period resulting in noise, and short warm-up period causing passengers to feel cold. be able to.
Further, since the blown air volume of the blower does not change at the time of the above switching, it is possible to realize air volume control that does not make the passenger feel uncomfortable.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. First, a specific configuration of one embodiment will be described with reference to FIG. Here, FIG. 2 is a block diagram schematically showing the overall configuration of the air conditioner of one embodiment.

As shown in FIG. 2, a blower 19 which is a blower for generating an air flow in the duct 20 is arranged in the ventilation duct 20. An evaporator 12 is arranged downstream of the blower 19 so as to close the ventilation duct 20, and the evaporator 12 cools the air flow blown by the blower 19. Further, a heater core 13 is arranged at a downstream portion of the evaporator 12 so as to block the ventilation duct 20 by about half, and the heater core 13 reheats the cold air passing through the evaporator 12.

The air whose temperature is adjusted by the evaporator 12 and the heater core 13 is blown out through the face duct 15 toward the upper body of the passenger in the passenger compartment, or through the foot duct 16 toward the feet of the passenger. Or, it is blown out to the windshield through a diff duct (not shown).

An inside / outside air switching damper 6 for switching the intake ratio of the inside air and the outside air is arranged upstream of the blower 19. Further, an air mix damper 21 is disposed upstream of the heater core 13 to control the temperature of the air blown into the vehicle compartment by switching the ratio of the air passing through the heater core 13. Here, the air mix damper 21 is a temperature adjusting means. Also face duct 15 and foot duct 16
A blowout mode switching damper 17 that switches the air blown into the vehicle compartment between the face duct 15 and the foot duct 16 is disposed in the branching portion.

The temperature of the air passing through the face duct 15 is detected by the upper outlet temperature sensor 8, and the detection result is output to the electronic control unit (hereinafter referred to as ECU) 7 as a digital signal. Further, the temperature of the air passing through the foot duct 16 is detected by the lower outlet temperature sensor 9, and the detection result is output to the ECU 7 as a digital signal. Here, the lower outlet temperature sensor 9 is the outlet temperature detecting means of the present invention.

Reference numeral 1 is a vehicle room temperature sensor which is a vehicle room temperature detecting means for detecting a vehicle interior temperature, 2 is an outside air temperature sensor which is an outside air temperature detecting means for detecting an outside air temperature, 3 is a solar radiation sensor for detecting an insolation amount, and 10 Is a temperature setter which is a vehicle room temperature setting means for setting a target set temperature in the vehicle interior. The output signals of the above sensors and temperature setter are output to the ECU 7.

The ECU 7 is a central processing unit (hereinafter referred to as CP
U), a ROM, a RAM, and a well-known microcomputer having an input / output interface. Then, based on the signals from the respective sensors and the temperature setting device, arithmetic processing is performed according to a predetermined program and map, and signals for controlling the respective actuators are output. The ECU 7 is activated by a signal from an ignition key (not shown). The programs and maps will be described later with reference to FIGS. 4 to 8.

After the above-mentioned arithmetic processing, the ECU 7 performs the internal / external air servo motor 5 and the air mix server based on the arithmetic result.
A control signal is output to the blower motor 14 and the blowout mode servomotor 18, and the inside / outside air servomotor 5, the air mix servomotor 14, and the blowout mode servomotor 18 are output.
Inside and outside air switching damper 6, air mix damper 2 respectively
1 and the blowout mode switching damper 17 are driven. The ECU 7 also outputs a control signal to the blower controller 4. The blower controller 4 receives the signal and controls the rotation speed of the blower motor 11 to control the strength of the air flow blown by the blower 19.

Next, the control method of the blower 19 will be described with reference to FIG.
Will be explained. Here, FIG. 3 is a drive circuit diagram of the blower motor used in the air conditioner of the present embodiment. The ECU 7 detects the blower voltage VM at the terminal 4 in order to perform feedback control of the voltage applied to the blower 19 according to the above-described arithmetic processing. The ECU 7 also applies a control input from the terminal 3 to the blower controller 4 to control the output voltage BLW. Terminal 2 connects the blower motor 11 to the battery voltage (+
B) is a terminal that drives a bypass relay 4a that short-circuits the output terminal of the blower controller 4, and terminal 1 is a terminal that drives a main relay 4b that supplies power to the blower motor 11. Again 4c
Is a power transistor and 4d is a thermal fuse.

Next, the operation of this embodiment will be described with reference to FIGS. 4 is a flow chart showing the flow of control of the microcomputer in the ECU 7,
FIG. 5 is a flowchart showing a specific control flow in step 104 in FIG. 6 is a map for determining whether or not to warm up according to the target outlet temperature, FIG. 7 is a map showing the air volume V ₂ according to the target outlet temperature, and FIG. ₅ is a map showing the air volume V ₁ according to the signal (lower temperature).

In this embodiment, as shown in FIG. 4, the initial value of the warm-up flag (WUF) is set to 0 in step 101, and then in step 102 the vehicle room temperature sensor 1, the outside air temperature sensor 2, and the solar radiation sensor. 3 and each signal from the temperature setter 10 are read. And step 10
At 3, the target blowout temperature (hereinafter referred to as TAO) blown into the vehicle compartment is obtained based on the read signals.

Here, how to obtain TAO will be described.
The vehicle room temperature detected by the vehicle room temperature sensor 1 is T _r , the outside air temperature detected by the outside air temperature sensor 2 is T _am , the amount of solar radiation detected by the solar radiation sensor 3 is T _s , and the set temperature set in the temperature setter 10 is T _set , the vehicle room temperature gain that is multiplied by the vehicle room temperature T _r is K _r , and the outside air temperature gain that is multiplied by the outside air temperature T _am is K _am ,
Assuming that the solar radiation gain that is multiplied by the solar radiation amount T _s is K _s , the temperature setting gain that is multiplied by the set temperature T _set is K _set , and the correction constant is C, TAO is calculated based on the calculation formula described in the following formula 1. It That is, the control mechanism in step 103 is temperature information calculation means.

[0028]

[Number 1] After determining the TAO at _{TAO = K set * T set -K} r * T r -K am * T am -K s * T s + C step 103, then step 1
Optimal blower motor 1 according to the situation at 04
Determine the supply voltage to 1. That is, the optimum air volume blown by the blower 19 is obtained. That is, in step 104, it is determined whether to perform warm-up control or steady control, and the optimum air volume is obtained in each case.

Therefore, in step 104, the subroutine shown in FIG. 5 is executed. When this subroutine is first executed here, the initial value of the warm-up flag (WUF) is 0 in step 101, so W
UF is not standing (WUF = 0).

First, at step 110, it is judged if warm-up control should be performed. The determination is made by the ECU
The determination is performed according to a map (FIG. 6) stored in advance in the microcomputer in FIG. 7, and the determination value f, which is the vertical axis of FIG. 6, is determined by f = 0 or f = 1. The control mechanism in step 110 is the warm-up determination means of the present invention.

When it is judged in step 110 that the warm-up should not be performed (NO), that is, when the judgment value f in FIG. 6 is f = 0, the ECU is judged in step 111.
Blower 1 as shown in the map stored in Figure 7 (Figure 7)
The air volume blown out by 9 is controlled to V _2, and the warm-up flag (WUF) is set in step 112 (WUF = 1). Here, V ₂ is the air volume corresponding to TAO obtained in step 103, and is an air volume suitable as the air volume blown out during the steady control. In the present embodiment, the second
The map shown in FIG. 7 is substituted for the air volume calculation means.

When it is determined in step 110 that the warm-up should be performed (YES), that is, when the determination value f in FIG. 6 is f = 1, it is determined in step 113 whether or not the warm-up flag is set. Find out. That is W
Check whether UF = 1. Where WUF = 1 (YES)
If so, as can be seen from step 112 above, it is not necessary to perform warm-up control in the future, that is, steady control must be performed, so step 11
1 is controlled. If WUF = 1 is not (NO),
Go to step 114.

In step 114, the lower outlet temperature sensor 9
Output signal from (hereinafter, this output signal is referred to as TAH)
Of the blower air volume V ₁ of the blower 19 and TAO
And the magnitude of the blown air volume V ₂ of the blower 19 according to the above. Here, the value of the air volume V ₁ is the blower 19 according to TAH.
It is obtained according to the map (FIG. 8) showing the blown-out air volume. The first air flow rate calculation means of the present invention is replaced with the map shown in FIG. 8 in this embodiment.

At step 114, the lower outlet temperature sensor 9
If it is determined that the blown air volume V ₂ according to the target blown air temperature (TAO) is larger than the blown air volume V ₁ according to the output signal (TAH) from (YES), step 11
The air volume blown by the blower 19 at 5 is V ₁ shown in FIG. That is, during the warm-up control, when the air volume V ₁ suitable for the warm-up control is smaller than the air volume V ₂ suitable for the steady control, if the air volume blown out by the blower 19 is set to V ₂ , the occupant will feel a cold wind. In such a case, the smaller air volume (V ₁ ) is selected as the air volume blown out by the blower 19 because the air is blown and it becomes uncomfortable. That is, during the warm-up control, the amount of air blown by the blower 19 is made as small as possible so as not to make the passenger's mood uncomfortable. The control mechanism in step 115 is the air volume selecting means of the present invention.

When it is determined in step 114 that V ₁ <V ₂ , the air volume blown by the blower 19 is set to V in step 115.
Return as ₁ . As this control is repeated, the magnitude of V _{1 and} the magnitude of V ₂ come close to each other. Then, eventually, V ₁ = V ₂ and V ₁ > V ₂ . That is, in step 114, it is determined that V ₁ ≧ V ₂ (NO). The air flow rate be switched from V ₁ to V ₂ at the moment when the V ₁ = V ₂ is not changed.

Therefore, when V ₁ ≧ V ₂ , the blower 19
Even if the blown-out air volume is set to the airflow rate V ₂ suitable for the steady control, there is no change in the blown air volume of the blower 19, and the warm-up control can be smoothly shifted to the steady control. In other words, the timing for returning the air volume blown by the blower 19 to the air volume V ₂ suitable for steady control is obtained in step 116. The control mechanism in step 116 is the air volume selection means of the present invention.

When the air volume blown by the blower 19 is set to V ₂ in step 116, a warm-up flag (WUF) is set in step 117. That is, in step 116, the warm-up control is completed, and the normal control is returned to, so that WUF = 1.

When the amount of air blown by the blower 19 is determined as described above, the blowout mode is obtained at step 105 shown in FIG. Since the method for obtaining the blowout mode is already known, detailed description will be omitted here.

When the blowout mode is obtained in step 105, the opening degree of the air mix damper 21 is obtained in step 106. Here, how to obtain the opening degree of the air mix damper 21 will be described.

In the upper blowing mode, that is, when air is blown through the face duct 15 toward the upper body of the occupant, the blowing temperature detected by the upper blowing temperature sensor 8 is TAV, and TAO shown in the above equation 1 is used. Deviation En
(= TAO-TAV) is calculated.

When En is obtained, the proportional gain is Kp, the integration time is Ti, the sampling time is θ, the differentiation time is Td, the opening of the air mix damper 21 is SWn, and the control value of the previous air mix damper opening is SWn. −1, SWn is calculated according to the following mathematical formula 2.

[0042]

[Formula 2] SWn = SWn-1 + Kp ((En-En-1) + θ * En / Ti + Td * (En-2En-1 + En-2) / θ) Also, in the lower blowing mode, that is, when the air is the foot duct. When blown through 16 towards the occupant's feet,
Blow-out temperature TAH and TAO detected by the lower blow-out temperature sensor 9
The deviation En (= TAO-TAH) is calculated. When En is calculated, the opening degree SWn of the air mix damper 21 is calculated by the above-described mathematical expression 2 as in the case of the upper blowing mode.

In the vertical blowing mode, that is, when air is blown into the vehicle compartment through the face duct 15 and the foot duct 16, En is set to TAO- (TAV + TAH).
The opening degree SWn of the air mix damper 21 is calculated by the above mathematical expression 2 as / 2.

At step 106, the air mix damper 2
When the opening degree of 1 is obtained, then in step 107, a control signal is sent to the blower controller 4 so that the blown air volume V of the blower 19 becomes the air volume obtained in step 104. Then, the blower controller 4 receives the signal, controls the energization of the blower motor 11, and drives the blower 19.

In step 108, the air mix servomotor 14 is controlled so that the opening of the air mix damper 21 becomes the air mix damper opening SWn obtained in step 106. Then, in step 109, the blowout mode switching damper 17 is controlled so that the blowout mode becomes the blowout mode obtained in step 105. Then return.

As a result of the operation as described above, the target outlet temperature TAO, the lower outlet temperature TAH, and the blower 19
The blown-out air volume V is as shown in FIG. Here is a brief summary of the explanations so far. Note that, in FIG. 9, the solid line of the blown air volume V indicates the actual air volume blown out from the blower 19.

As shown in FIG. 9, TAH is low and TAO is high in the initial stage of warm-up control. At this time, the blower air volume V of the blower 19 adopts the air volume V ₁ according to TAH, and its size is relatively small. And TAO and T
The difference between AH and AH gradually decreases, and the difference between the air volume V ₁ according to TAH and the air volume V ₂ according to TAO also gradually decreases. Then, when the time t exceeds t = t ₁ , V ₁ ≧ V ₂ , and the blown air volume V of the blower 19 is the air volume V corresponding to TAO.
It becomes ₂ .

The warm-up control is completed when t = t ₁ . Then, after that, TAO≈TAH. Further, since the vehicle interior temperature at this time is increased by the warm-up control, TAO decreases from the above formula 1 as time passes. TAH also decreases accordingly.

By the way, TAO when t = t ₂ (≈TA
H) is about 65 ° C. While blowing air volume of the blower 19 at this time is V _2, V ₂ at this time from the figure 1 it can be seen that less than V _1.

From time t = t ₂ to time t = t ₃ , TAO (= TAH) decreases, and as can be seen from FIG. 1, the blown air volume V of the blower 19 is V ₂
Is smaller than V ₁ , and the amount of air actually blown out from the blower 19 is also V ₂ .

After t = t ₃ , V ₂ > V ₁ is established due to the relationship between the characteristics of V _{1 and} the characteristics of V ₂ stored in the microcomputer in the ECU 7. This shows the left part from the intersection A in FIG.

However, in this embodiment, since the end management of the warm-up control is performed by the warm-up flag (WUF), once the warm-up control is completed,
Warm-up control is not performed unless the ignition key is turned off and then turned on again. That is, once the warm-up control is completed, the blown air volume V of the blower 19 remains V = V ₂ until the ignition key is turned off.

Therefore, as can be seen from FIGS. 9 and 1,
When t = t ₃ is exceeded, V ₂ > V _{1 in} terms of characteristics, but the air volume V actually blown out by the blower 19 is V ₂ , and even if V ₂ > V _{1 in} terms of characteristics, the air volume blown out of the blower 10 is It cannot be V ₁ . In this way, after the warm-up control is completed, there is no fear that the warm-up will occur every time it is determined that the warm-up should be performed in step 110 of FIG. 5, and the blown air volume V will also change.

FIG. 9 shows the blown air volume in the conventional example in which warm-up control is performed using the water temperature sensor. As described above in detail, in the present embodiment, the air volume V ₁ suitable for the warm-up control is compared with the air volume V ₂ suitable for the steady control, and the smaller one is output as the blow-out air volume V of the blower 19, so that the warm-up is performed. The optimum timing for ending the control and returning to the steady control can be obtained.

Further, since the warm-up flag (WUF) is used in this embodiment, once the warm-up is completed, the warm-up control is not performed again until the ignition key is turned off. It is preventing.

Incidentally, FIG. 10 shows a diagram corresponding to the claims of the present invention.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a map showing a blower airflow rate according to a target blowout temperature and a lower blowout sensor according to an embodiment of the present invention.

FIG. 2 is a block diagram schematically showing an overall configuration of an air conditioner according to an embodiment of the present invention.

FIG. 3 is a drive circuit diagram of a blower used in the air conditioner.

FIG. 4 is a flowchart showing a control flow of a microcomputer used in the air conditioner.

FIG. 5 is a flowchart specifically showing control of a subroutine of air volume calculation in the flowchart of FIG.

FIG. 6 is an explanatory diagram of a map showing whether or not to warm up used in the flowchart.

FIG. 7 is an explanatory diagram of a map showing a second air volume according to a target outlet temperature used for the air volume calculation.

FIG. 8 is an explanatory diagram of a map showing a first air volume according to a lower outlet temperature used in the air volume calculation.

FIG. 9 is a graph showing a transition of a target blow temperature, a lower blow temperature, and a blower blow air volume in the apparatus of the one embodiment.

FIG. 10 is a diagram corresponding to the claims of the present invention.

[Explanation of symbols]

 1 Vehicle room temperature sensor as vehicle temperature detecting means 2 Outside air temperature sensor as outside temperature detecting means 9 Lower outlet temperature sensor as outlet temperature detecting means 10 Temperature setting device as vehicle room temperature setting means 19 Blower as blower 20 Ventilation duct 21 Air mix damper M1 as temperature adjusting means Temperature information calculating means M2 Warm-up judging means M3 First air volume calculating means M4 Second air volume calculating means M5 Air volume selecting means M6 Air volume controlling means

Claims (1)

Claim: What is claimed is: 1. A blower for generating an air flow in a ventilation duct, a temperature adjusting means for adjusting the temperature of the air flow, and a temperature adjusting means installed in the ventilation duct. A blow-out temperature detection unit that detects the adjusted blow-out temperature of the air flow, a warm-up determination unit that determines whether warm-up control should be performed based on a predetermined condition, and outputs a warm-up determination result, and at least an outside air temperature. The temperature information blown out into the vehicle compartment is calculated based on the signals from the outside air temperature detection means for detecting the temperature, the vehicle room temperature detection means for detecting the vehicle interior temperature, and the vehicle room temperature setting means for setting the target set temperature in the vehicle interior. Based on temperature information, temperature information calculating means for controlling the temperature adjusting means, and the temperature information, the blowout temperature, and the warm-up determination result, the blower. In a vehicle air conditioner configured with an air volume control unit that outputs a control signal for controlling, the air volume control unit calculates a first air volume signal to be blown by the blower based on the blowout temperature. Means, second air volume calculation means for calculating a second air volume signal to be blown by the blower based on the temperature information, the first air volume signal, the second air volume signal, and the warm-up determination result are input. When the warm-up determination result determines that the warm-up should be performed, the first air volume signal is selected, the first air volume signal and the second air volume signal are compared, and the first air volume signal is obtained. The second
An air conditioner for a vehicle, comprising: an air volume selecting means for selecting the second air volume signal in place of the first air volume signal when the air volume signal approaches.