JP2853476B2 - Vehicle air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle air conditioner for instructing an increase in an engine idle speed during a compressor operation.

[Prior art]

[0002] A vehicle comprising a compressor for compressing a refrigerant driven by an engine, an evaporator for vaporizing the refrigerant compressed by the compressor, and a blower fan for blowing the introduced air through the evaporator into the vehicle interior. Air conditioners for air conditioners are known. In vehicles equipped with this type of air conditioner, for example, a valve (AAC valve) for adjusting an auxiliary air flow rate is provided in an air passage bypassing a throttle valve, and the AAC valve is used when the compressor is operated (ON). The engine idle speed is increased by opening the engine by a certain opening (for example, Nissan Service Bulletin June 1987, No. 578, No. B-7)
1 page). Here, in this specification, the operation of the compressor (ON) indicates a state in which the compressor discharges the refrigerant, and the operation of the compressor (OFF) indicates a state in which the refrigerant discharge amount of the compressor is almost zero. Therefore, for example, in the case of a variable displacement compressor, it is not actually in a non-operating state, but when the refrigerant discharge capacity is zero, it is assumed that the compressor is not in operation.

[0003]

SUMMARY OF THE INVENTION In such a vehicle,
Even when the heat load is not so large, the engine idle speed is increased in conjunction with the turning on of the compressor. However, when the heat load is not so large, a sufficient cooling performance can often be obtained without increasing the engine idle speed and increasing the refrigerant flow rate. This leads to poor fuel economy.

Therefore, a sensor for detecting the air temperature immediately after the evaporator (hereinafter referred to as the temperature immediately after the evaporator) is provided, the thermal load on the evaporator is estimated based on the temperature immediately after the evaporator, and the engine idle speed is determined according to the estimation result. It is conceivable to control. According to this, when the heat load on the evaporator is small, the idling speed does not increase even if the compressor is turned on, so that the fuel efficiency is improved. By the way, the temperature immediately after the evaporation is originally
For example, it is used for control of turning on and off a fixed displacement compressor near the freezing limit of an evaporator.However, when a variable displacement compressor is used, the amount of refrigerant discharged can be controlled according to the required cooling capacity. Therefore, there is almost no need to turn the compressor on and off, and a temperature sensor immediately after evaporation is unnecessary. For this reason, in the method of controlling the engine idle speed based on the temperature immediately after the evaporation as described above, it is necessary to newly provide a temperature sensor immediately after the evaporation when adopting a system without the temperature sensor immediately after the evaporation, which leads to a cost reduction. There is a problem that leads to up. On the other hand, if the idle speed is reduced when the thermal load is large, such as during a cool down, the cooling capacity may be reduced.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a vehicle for which a suitable idle speed control can be performed without using a temperature sensor immediately after the evaporation and without lowering the cooling capacity under a large heat load and without deteriorating fuel efficiency. An object of the present invention is to provide an air conditioner.

[0006]

Means for solving the problem will be described with reference to FIG.
The vehicle air conditioner according to the first aspect of the present invention includes an engine 10
Compressor 102 driven by the compressor 1 to compress the refrigerant
And an evaporator 103 for vaporizing the refrigerant compressed by the compressor 102, a variable speed blower fan 104 for passing air introduced from outside the vehicle through the evaporator 103 and blowing air into the vehicle interior, and an engine when the compressor is not operating. A command for maintaining the idle speed at the first speed is output, and a speed increase command for increasing the engine idle speed to a second speed higher than the first speed when the compressor is operating. Speed command means 105 for outputting the temperature, and the outside air temperature sensor 1 for detecting the outside air temperature
06, fan speed determining means 107 for determining the speed of the blower fan based on at least the temperature in the vehicle compartment, and when the determined blower fan speed exceeds the predetermined speed when the outside air temperature is within a predetermined range. A correcting means 110 for correcting the blower fan speed to a predetermined speed or less, a heat load determining means 109 for determining a heat load based on the outside air temperature and the determined or corrected blower fan speed, and a determined or corrected blower fan. If the fan speed is less than the predetermined speed,
And, when the heat load is less than a predetermined value, a prohibiting means 108 for prohibiting the output of the rotational speed increasing command by the rotational speed commanding means 105 even when the compressor is operating is provided, thereby solving the above problem. . According to a second aspect of the present invention, there is provided a compressor, an evaporator, a blower fan, an outside air temperature sensor, a judging means for judging a speed of the blower fan, and a judging means for judging a heat load based on the outside air temperature and the blower fan speed. A first thermal load determining means, a second thermal load determining means for determining a thermal load based on at least a vehicle interior temperature and a target value of the vehicle interior temperature, separately from the first thermal load determining means; And a rotational speed command means for controlling the engine idle rotational speed based on the result of the determination by the second heat load determining means. The control contents of the rotation speed command means are as follows. (A) When the compressor is not operating, a command for setting the engine idle speed to the first speed is output. (B) When the compressor is operating and the thermal load determined by the second thermal load determining means is less than a predetermined value, the blower fan speed is less than the predetermined speed and the first thermal load determining means determines. When the applied heat load is less than the predetermined value, a command for setting the engine idle speed to the first speed is output, and otherwise, the second engine speed is set to a second value higher than the first speed. A command to output the number of rotations is output. (C) When the compressor is operating and the heat load determined by the second heat load determining means is equal to or greater than a predetermined value, the engine idle speed is reduced to the second speed regardless of the determination result of the second heat load determining means. A command to output a third rotation speed higher than the second rotation speed is output.

[0007]

(1) When the determined blower fan speed exceeds the predetermined speed when the outside air temperature is within the predetermined range, the blower fan speed is corrected to the predetermined speed or less. Then, the heat load is determined based on the outside air temperature and the determined or corrected blower fan speed, and when the determined or corrected blower fan speed is lower than the predetermined speed and the heat load is lower than the predetermined value, Even when the compressor is operating, the output of the rotation speed increase command by the rotation speed command means 105 is prohibited. (2) When the compressor operates and the heat load determined by the second heat load determination means is less than a predetermined value, the blower fan speed is less than the predetermined speed and the first heat load is reduced. When the heat load determined by the load determining means is less than a predetermined value, a command for setting the engine idle speed to the first speed (the speed when the compressor is off) is output. At other times, a command is output to set the engine idle speed to a second speed higher than the first speed.
When the compressor is operating and the thermal load determined by the second thermal load determining means is equal to or greater than a predetermined value, the engine idle speed is set to the second rotational speed regardless of the determination result of the second thermal load determining means. A command for setting the third rotation speed higher than the number is output.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. 2, a throttle valve 12 is provided in an intake passage 11 of an engine 10, and a bypass passage 1 is provided in a passage 13 that bypasses the throttle valve 12.
An auxiliary air flow control valve (AAC valve) 14 for adjusting the auxiliary air flow passing through 3 is provided. AAC
The opening degree of the valve 14 is controlled by an idle speed control circuit 31, and the engine idle speed is controlled by adjusting the auxiliary air flow rate in accordance with the operating state of the engine or a command value from an air conditioning control circuit 26 described later. .

Reference numeral 20 denotes an air conditioner. The air conditioner 20 is supplied via a variable capacity compressor 21 driven by the engine 10 and a condenser, a liquid tank, and an expansion valve (not shown) which are compressed by the compressor 21. Evaporator 2 for evaporating the refrigerant and cooling the passing air
2 and a blower fan 23 that blows outside air introduced from an inlet (not shown) through the evaporator 22 and blows air into the vehicle interior.
And a blower fan control circuit 27 that drives and controls the blower fan 23. The compressor 21 is turned on / off by a command from an air conditioning control circuit 26 via a relay 25, and controls the discharge amount of the refrigerant according to a required amount of cooling capacity.

The air-conditioning control circuit 26 has an outside air temperature T.
An outside air temperature sensor 41 for detecting amb, an indoor temperature sensor 42 for detecting a vehicle interior temperature Tinc, and a solar radiation sensor 43 for detecting an amount of solar radiation Qsun are connected.
, A fan switch 45 for manually switching the speed of the blower fan 23, and an off switch 46 for turning off the air conditioning control are also connected. In this embodiment, by operating the fan switch 45, the speed of the blower fan 23 can be switched in four stages from the first speed to the fourth speed in ascending order of the air volume. Although the fan switch 45 is shown as a single switch for convenience, it is actually composed of a plurality of switches. The control circuit 26 turns on / off the compressor 21 according to the state of the air conditioner switch 44 or the blower fan switch 45 and the vehicle thermal load, and controls the fan applied voltage Vf via the blower fan drive circuit 27 to control the blower fan. In addition to controlling the speed (air volume) of the engine 23, a command value of the engine idle speed is determined according to the outside air temperature Tamb and the blower fan speed, and is output to the idle speed control circuit 31.

Next, the procedure of air-conditioning control and engine idle speed control in this embodiment will be described with reference to the flowcharts of FIGS. FIG. 3 shows an air conditioning control circuit 26.
The basic air-conditioning control performed in step S110
Then, in the normal auto air conditioner mode, for example, the set temperature Tptc is initially set to 25 ° C. Next, in step S120, various information from each sensor is input. The data information of these sensors will be specifically described. The set temperature Tptc is obtained from a control panel (not shown), and the vehicle interior temperature Tinc is obtained from the interior temperature sensor 42.
Thus, the outside air temperature Tamb is given from the outside air temperature sensor 41, and the solar radiation amount Qsun is given from the solar radiation sensor 43, respectively.

In step S130, the outside air temperature sensor 41
Is processed to a value Tam corresponding to the actual outside air temperature, excluding the influence from other heat sources on the outside air temperature Tamb obtained from. In step S140, the solar radiation amount information from the solar radiation sensor 43 is corrected to a value Q'sun as a heat amount suitable for subsequent conversion. In step S150, a value T 'obtained by correcting the set temperature Tptc set on the control panel according to the outside air temperature.
Process to ptc. In step S160, T'ptc, Tin
Using c, Tam, and Q'sun, Xm = (A + D) T'ptc + B.Tam + C.Q'sun-D.T
The target outlet temperature Xm is calculated by inc + E (where A to E are constants), and the opening of the air mix door (not shown) is controlled in accordance with the target outlet temperature Xm.

In step S170, the on / off of the compressor 21 is controlled. In step S180, an engine idling speed command control (to be described in detail later) is performed. In step S190, the blowing based on the calculated target blowing temperature Xm is performed. Set an exit. In step S200, the suction port,
That is, the selection switching between the outside air inlet and the inside air inlet is controlled, and in step S210, the blower fan 23 is controlled to control the air volume from the outlet. Thereafter, the process returns to step S120.

FIG. 4 shows the details of the engine idling speed command control in step S180 (FIG. 3). First, in step S1, it is determined whether the compressor 21 is on (operating) and off (non-operating). ), In step S2, the idling speed command value Ne is changed to the idling speed N ₁ (corresponding to the first speed, when the compressor is off).
For example, it is set to 650 rpm. The command value Ne is input to the idle speed control circuit 31, where actual idle speed control is performed, which will be described in detail with reference to FIG. On the other hand, when the compressor 21 is turned on the process proceeds to step S3, to determine the state N ₂ or N ₃ from the characteristics shown in accordance with the target air temperature Xm which is the arithmetic. Here, the target outlet temperature Xm decreases as the vehicle thermal load increases.

[0015] In step S4 to determine the state determined in step S3, if N _3, the idling rotation speed command value Ne corresponds to a high N ₃ (third rotation speed than N ₁ in step S5 , For example, 850 rpm). On the other hand, the process proceeds to step S6 when it is determined that the N _2, whether less than the fan applied voltage Vf obtained by control of the air flow rate of the blower fan to be described later 9v, namely the judgment blower fan speed whether less than a predetermined speed I do. If Vf ≧ 9v, the routine proceeds to step S14, where the idling speed command value Ne is set to N
An intermediate value N ₂ between ₁ and N ₃ (corresponding to the second rotation speed, for example, 750 rpm) is set, and if Vf <9 V, the process proceeds to step S7. In steps S7 and S8, the currently set blower fan speed is determined. If MH (blower fan voltage = 6.25 to 9.0 V), step S
Proceeding to 9, the reference value T1 of the outside air temperature is set to 22. When the blower fan speed is ML (blower fan voltage = 4 ~
6.25v), Lo (blower fan voltage = 4v or less), T is set in steps S10 and S11, respectively.
1 is set to 24,26.

[0016] In step S12, based on the characteristics shown in the figure, the outside air temperature Tamb to determine whether state N ₁ or N ₂ depending on whether exceeds the reference value T1, which is the set. Step S13 determines the result in the idle speed command value Ne is set to N ₁ proceeds to step S2 if N _1, sets the command value Ne into N ₂ in step S14, if N ₂ . Here, the reference value T used in step S12 is used.
1 is set higher as the blower fan speed increases, so that the determination in step S13 is that the outside air temperature T
This means that it is determined whether the logical product of amb and the blower fan speed is less than a predetermined value.

FIG. 5 shows only a part of the actual engine idle speed control procedure by the idle speed control circuit 31. In step S21, the air conditioning control circuit 2
6 to determine the idle speed command value Ne input from
If Ne ≠ N ₂ and Ne ≠ N ₃ , that is, if it is determined that idle-up is not to be performed, in step S24, the opening of the AAC valve 14 is feedback-controlled so that the actual engine idle speed N becomes N ₁ (650 rpm). Is done. On the other hand, step S21 is affirmed, it is determined to perform the idle-up control proceeds to step S25, Ne = N ₂ when it is determined that the AAC in step S22
The valve 14 is opened by a predetermined value, and thereafter, the process proceeds to step S23, where the engine idle speed N becomes N ₂ (750 rpm).
m), the opening degree of the AAC valve 14 is feedback-controlled. Further, when it is determined that Ne = N ₃ in step S25, opens the AAC valve 14 by a predetermined value in step S26, then the process proceeds to step S27, so that the engine idle speed is N ₃ (850rpm) A
The opening of the AC valve 14 is feedback-controlled.

FIG. 6 shows the above step S210 (FIG. 3).
3 shows details of the blower fan air volume control. If it is determined in step S31 that the off switch 46 is on, the blower fan 23 is turned off in step S32, and the off switch 4
If it is determined that 6 is off, the process proceeds to step S33. If it is determined in step S33 that the fan switch 45 is on, the process proceeds to step S34. Steps S34 to S36 are processes for determining the blower fan speed instructed by the fan switch 45. If it is determined that the speed is the first speed, step S37 is performed.
Sets the blower fan applied voltage Vf to 4.0 V. If it is determined that the speed is the second speed, the third speed, or the fourth speed, the applied voltage Vf is set to 6.25 V in steps S38 to S40, respectively.
9.0 V and Vacc (highest voltage) are set respectively.
After steps S37 to S40, the process proceeds to step S34.

On the other hand, in step S33, the fan switch 4
5 is determined to be off, the constants L, M,
N and P are set to -82, -35, 65, and 131, respectively. Then, in step S42, the blower fan applied voltage Vf is determined based on the target blowing temperature Xm from the characteristics shown. In step S43, a correction for defining an upper limit value of Vf is performed based on the outside air temperature Tamb. More specifically, the upper limit value of Vf decreases from 12v to 9v when the outside air temperature Tamb ranges from 10 ° C to around 15 ° C, and from 25 ° C to 30 ° C.
Up to 12v. Therefore, according to this processing, for example, when the outside air temperature Tamb is around 20 ° C., even if the Vf determined in step S42 exceeds 9
Is limited to Thereafter, the process proceeds to step S44, and the determined application voltage Vf is applied to the blower fan 23.

The above is the control procedure in this embodiment. According to the procedure of FIGS. 4 and 5, the outside air temperature Tam
The heat load on the evaporator 22 is determined based on b and the blower fan speed. When the blower fan speed is lower than the predetermined speed and the heat load is lower than the predetermined value, the idle speed is N even when the compressor is operating. held by _1, it does not increase in N _2. Therefore, unnecessary increase in idle speed is avoided, and fuel efficiency can be improved. Further, since there is no need to use a sensor immediately after the evaporation as in the conventional case, even when employing a system without a temperature sensor immediately after the evaporation, it is not necessary to newly provide a temperature sensor immediately after the evaporation, and the cost can be reduced. Further, even when the blower fan speed is equal to or higher than a predetermined speed, when the logical product is equal to or higher than a predetermined value, that is, when the heat load on the evaporator 22 is high,
Since the idle speed during compressor operation is increased N _2, it is possible to obtain a sufficient cooling performance even when the heat load such as during cool-down is large. Since the opportunity for air conditioning in the cool-down state is smaller than the opportunity for air conditioning in the stable cooling state, the fuel efficiency can be improved as a whole.

If the engine idling speed is low when the blower fan speed is higher than a predetermined speed (for example, when the blower fan applied voltage Vf is 9 V or higher), the charge / discharge balance of the alternator may be lost and the battery may run out. However, in the above control, when the blower fan speed is 9 V or more, the idling speed always increases to N ₂ irrespective of the logical product, so that the charge / discharge balance of the alternator is always properly maintained to prevent the battery from running out. it can.

Further, in this embodiment, as shown in FIG.
Automatic control for determining the blower fan applied voltage Vf (blower fan speed) based on the target blow temperature Xm, that is, the vehicle heat load, is performed. At this time, the outside air temperature Tamb is 1
When the temperature is in the range of 0 ° C. to 30 ° C., the upper limit of the applied voltage Vf is limited, and the following operation and effect can be obtained. Generally, in the auto control, when the outside air temperature Tamb is in the range of 10 ° C. to 30 ° C., the blower fan is rarely operated at the highest speed (for example, the applied voltage of 12 V). However, for example, when the vehicle is parked in the sun for a long time, the room temperature rises considerably due to the solar radiation. Therefore, if the upper limit of the applied voltage Vf is not limited as described above, if the outside air temperature is, for example, 20 ° C. Even when the air conditioner is operated, the blower fan may be operated at the highest speed. Then, the engine idle speed in this case is likely to increase in N _2. However, in general, when the outside air temperature is 10 ° C. to 30 ° C., the user does not feel much discomfort even if the blower fan speed is not set to the highest speed. Therefore, in this embodiment, the blower fan speed is limited. The outside air temperature Tamb ranges from 10 ° C. to 30 ° C.
If the blower fan speed is 9 v
It was kept below. Therefore, at this time, there is a high possibility that the engine idling speed is maintained at a low speed without being increased, thereby improving fuel efficiency.

Further, in this embodiment, as shown in FIG.
If the target air temperature Xm during the compressor ON is equal to or less than a predetermined value, that is, when the vehicle thermal load is above a predetermined value, the rotational speed of the normal compressor on the engine idle speed (second speed) than N ₂ Is set to a higher rotation speed N ₃ , so that an effect that a sufficient cooling power can be obtained under a high heat load can be obtained. Also, if the engine idling speed is kept at N ₂ during a high heat load, the cooling power is insufficient and the blower fan is operated at a high speed for a long time. there is, according to this embodiment, the blower fan by setting the idle speed to the N ₃ is not being operated for a long time a high speed, the passenger will not be feel uncomfortable.

In the configuration of the above embodiment, the air-conditioning control circuit 26 constitutes the rotation speed command means 105, the judgment means 107, the prohibition means 108, the fan speed determination means and the correction means. In the above description, the reference value of the outside air temperature is set lower as the blower fan speed is higher, and the outside air temperature and the blower fan are determined by determining whether the detected outside air temperature is equal to or higher than the set reference value. Although it is determined whether the logical product of the speeds is equal to or greater than a predetermined value, the direction of the logical product determination is not limited to the embodiment. Further, a threshold value for determining the target blow-out temperature Xm used in FIG. 4 and a reference value of the outside air temperature determined by the blower fan speed are as follows:
It is not limited to the numerical values shown. Further, the present invention can be applied to a compressor using a fixed displacement compressor.

[0025]

According to the first aspect of the present invention, when the blower fan speed is lower than the predetermined speed and the heat load determined based on the outside air temperature and the blower fan speed is lower than the predetermined value (the heat load on the evaporator). Is low), an increase in the idle speed is prohibited even during the operation of the compressor, so that unnecessary idle-up is not performed, which contributes to an improvement in fuel efficiency. In addition, when the blower fan speed is equal to or higher than the predetermined speed, the idling speed always increases regardless of the outside air temperature, so that the charge / discharge balance of the alternator is not disrupted and the battery can be prevented from running out. Further, when the blower fan speed exceeds the predetermined speed when the outside air temperature is within the predetermined range, the blower fan speed is corrected to the predetermined speed or less, so that unnecessary idle-up in a specific case is avoided, and further Fuel efficiency can be improved. According to the invention of claim 2, the blower fan speed is lower than the predetermined speed, and based on the outside air temperature and the fan speed, at least when the heat load determined based on the vehicle interior temperature and its target value is lower than the predetermined value. When the heat load determined by the above is less than the predetermined value, the idle speed does not increase even when the compressor is operating, so that unnecessary idle-up is not performed as described above, which contributes to improvement of fuel efficiency. On the other hand, when the blower fan speed is equal to or higher than the predetermined speed, the idle speed always increases, so that the charge / discharge balance of the alternator is not disrupted and the battery can be prevented from running out. When the heat load determined based on at least the vehicle interior temperature and the target value thereof is equal to or higher than a predetermined value, the engine idle speed becomes the third engine speed regardless of the heat load determined based on the outside air temperature and the fan speed. Increased to the number of revolutions. That is, the fact that the heat load determined based on the vehicle interior temperature and its target value is equal to or more than the predetermined value means that the occupant desires strong cooling, and therefore, regardless of the level of the heat load on the evaporator. To increase the engine speed to enhance cooling.
Thus, the occupant does not feel discomfort due to insufficient cooling.

[Brief description of the drawings]

[Fig. 1] Claim correspondence diagram

FIG. 2 is an overall configuration diagram of an embodiment of the present invention.

FIG. 3 is a flowchart showing basic air conditioning control.

FIG. 4 is a flowchart showing an example of a procedure of engine idle speed command control;

FIG. 5 is a flowchart illustrating an example of a procedure of actual engine idle speed control;

FIG. 6 is a flowchart showing a procedure of blower fan air volume control;

[Explanation of symbols]

 Reference Signs List 10 engine 13 bypass passage 14 auxiliary air flow control valve 20 air conditioner 21 compressor 22 evaporator 26 air conditioning control circuit 31 idle speed control circuit 41 outside temperature sensor 26 control circuit

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-59-156818 (JP, A) JP-A-2-23245 (JP, A) JP-A-2-98007 (JP, U) (58) Field (Int.Cl. ⁶ , DB name) B60H 1/32 623

Claims (2)

(57) [Claims] 1. A compressor driven by an engine to compress a refrigerant, an evaporator for vaporizing the refrigerant compressed by the compressor, and a variable speed for blowing air introduced from outside the vehicle through the evaporator into a vehicle interior. When the compressor is not operating, the blower fan outputs a command for maintaining the engine idle speed at the first speed, and when the compressor is operating, the engine idle speed is higher than the first speed. A rotation speed command means for outputting a rotation speed increase command for increasing the rotation speed to 2, an outside air temperature sensor for detecting an outside air temperature, and a speed of the blower fan based on at least a vehicle interior temperature.
Fan speed determining means for determining the temperature , the fan speed determining means determines when the outside air temperature is within a predetermined range.
If the blower fan speed exceeds the specified speed,
Correction means for correcting the afan speed to a predetermined speed or less ; heat load determination means for determining a heat load based on the outside air temperature and the determined or corrected blower fan speed; and the determined or corrected blower fan speed Is the prescribed
If the speed is less than and the heat load is less than a predetermined value,
An air conditioner for a vehicle, comprising: a prohibition unit that prohibits the output of the rotation speed increase command by the rotation speed command unit even when the compressor is operating. 2. The refrigerant is compressed by being driven by an engine.
Compressor and an evaporator that vaporizes the refrigerant compressed by the compressor.
And the air introduced from outside the vehicle through the evaporator.
A variable speed blower fan that blows air into the vehicle interior, an outside air temperature sensor that detects an outside air temperature , a determination unit that determines the speed of the blower fan, and a heat load based on the outside air temperature and the blower fan speed.
A first thermal load determining means for determining a load, and at least a vehicle interior separate from the first thermal load determining means.
Determines thermal load based on target temperature and cabin temperature
To a second heat load determining means, (a) shows the compressor is not operated, the engine idle
Output a command to set the rotation speed to the first rotation speed,
(B) when the compressor is operating and the second heat load
When the heat load determined by the load determination means is less than a predetermined value
The blower fan speed is lower than a predetermined speed and
The heat load determined by the first heat load determination means is a predetermined value.
If the engine idle speed is less than the first
Command to output the rotation speed of
Is higher than the first engine speed.
(C) outputs a command for setting a high second rotation speed.
Determining the second heat load during the operation of the compressor and the second heat load
If the heat load determined by the means is equal to or greater than a predetermined value,
Irrespective of the judgment result of the second heat load judgment means,
The engine idle speed is higher than the second speed.
Speed command for outputting a command to set a third speed
And a vehicle air conditioner.