JPH0516647A - Vehicle air conditioner - Google Patents

Abstract

PURPOSE:To prevent deterioration of the cooling performance or warming performance of a vehicle air conditioner by reducing the quantity of air from a blower fan only when vehicle heat loads are judged to be within a predetermined range as switching from fresh air intake to inside air circulation is commanded. CONSTITUTION:An air quantity control means 104 controls the quantity of air from a blower fan 103 according to vehicle heat loads and reduces the quantity of air from the blower fan 103 when switching from fresh air introduction to inside air circulation is commanded. A judging means 105 then determines whether or not vehicle heat loads are within a predetermined range. The air quantity control means 104 reduces the quantity of air from the blower fan 103 only when the vehicle heat loads are judged to be within the predetermined range as switching from fresh air introduction to inside air circulation is commanded. Therefore when the vehicle heat loads are considerably high or low the quantity of air from the blower fan 103 is not reduced, so preventing deterioration of the cooling performance or warming performance of the vehicle air conditioner.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner for a vehicle, which reduces the air volume of a blower fan when switching from introduction of outside air to circulation of inside air.

[0002]

2. Description of the Related Art In a general vehicle air conditioner, the outside air introduction for introducing the air outside the passenger compartment and the inside air circulation for introducing the air inside the passenger compartment can be switched by, for example, a switch operation. When switched, the fan noise increases due to the suction noise of the inside air inlet and the increase of the air volume due to the decrease of the vehicle interior pressure. Therefore, for the purpose of preventing the fan noise from increasing, there is known a vehicle air conditioner that automatically reduces the air volume of the blower fan when a command to switch from the outside air introduction to the inside air circulation is instructed (for example, , JP-A-64-41415).

[0003]

However, this conventional device always reduces the air volume of the blower fan when the switching from the outside air introduction to the inside air circulation is instructed regardless of the heat load of the vehicle. The air volume of the blower fan is also reduced when the load is considerably high (when strong cooling is required) or when it is considerably low (when strong heating is required), which reduces cooling or heating performance and reduces the set temperature. There is a problem that the arrival at is delayed.

An object of the present invention is to provide a vehicle air conditioner which normally reduces fan noise when switching from inside air circulation to inside air circulation and improves cooling and heating performance when the vehicle heat load is high or low. To provide.

[0005]

The invention according to claim 1 will be described with reference to FIG. 1A which is a diagram corresponding to the claims. In the invention of claim 1, the outside air introduction for introducing the air outside the vehicle compartment and the inside air circulation for introducing the air in the vehicle interior are performed. Instructing means 101 for instructing switching, switching means 102 for switching between introduction of outside air and circulation of inside air in accordance with the instruction of this instructing means 101, blower fan 103 for blowing the introduced air into the passenger compartment, and vehicle heat For a vehicle equipped with an air volume control means 104 for controlling the air volume of the blower fan 103 according to the load, and for reducing the air volume of the blower fan 103 when the instruction means 101 instructs switching from outside air introduction to inside air circulation. Applied to air conditioners. The air flow rate control means 1 is provided with a determination means 105 for determining whether or not the vehicle heat load is within a predetermined range.
The above problem can be solved by configuring 04 as follows. That is, the air volume control means 104 is the command means 101.
When the switch from outside air introduction to inside air circulation is instructed by, the air volume of the blower fan 103 is reduced only when it is determined that the vehicle heat load is within a predetermined range. Further, in particular, according to the invention of claim 2, when the vehicle heat load is determined to be within the predetermined range when the instruction means 101 instructs the switching from the outside air introduction to the inside air circulation, the vehicle heat load becomes farther from the predetermined range. The air volume control means 104 is configured to reduce the air volume reduction amount of the blower fan 103. Further, according to the invention of claim 3, the determining means 105 is configured to determine whether or not the vehicle heat load is within a predetermined range based on the blower fan speed determined according to the vehicle heat load. Furthermore, to explain with reference to FIG. 1 (b) which is a claim correspondence diagram, the invention of claim 4 is the above-mentioned command means 101, switching means 102, and blower fan 1.
03, and an air volume control means 204 for setting the air volume of the blower fan according to an air volume command from the outside. Then, a determination unit 205 for determining whether or not the air volume of the blower fan set by the air volume control unit 204 is less than a predetermined value is provided, and the air volume control unit 204 is configured as follows. That is, when the instruction means 101 instructs the air volume control means 204 to switch from the introduction of the outside air to the inside air circulation and the air volume of the blower fan 103 is determined to be less than the predetermined value, the blower fan 20 set as described above.
3 to reduce the air volume. Further, in the invention of claim 5, after the air volume of the blower fan 103 is reduced, the command means 101
When a command is issued to switch from the internal air circulation to the external air introduction, the air volume control means 104 and 204 are configured to increase the air volume after a lapse of a predetermined time from the instruction.

[0006]

[Action]

(1) When the invention instructing means 101 of claim 1 instructs the switching from the outside air introduction to the inside air circulation, the air volume control means 104 causes the blower fan 103 only when the vehicle heat load is determined to be within a predetermined range. Reduce the air flow. As a result, when the vehicle heat load is considerably high or very low, the air volume of the blower fan is not reduced, and the cooling performance or heating performance can be improved. (2) The invention air volume control means 104 of claim 2 reduces the air volume reduction amount of the blower fan 103 as the vehicle heat load deviates from a predetermined range when the air volume is reduced. (3) The invention determining means 105 according to claim 3 determines whether or not the vehicle heat load is within a predetermined range based on the blower fan speed determined according to the vehicle heat load. (4) When the invention instructing means 101 of claim 4 issues an instruction to switch from the outside air introduction to the inside air circulation and the air volume of the blower fan 103 is determined to be less than a predetermined value, the air volume control means 104 is set as described above. The air volume of the blower fan 103 is reduced. (5) Inventive air volume control means 104 and 204 according to claim 5, when the switching from the internal air circulation to the external air introduction is instructed after the air volume of the blower fan 103 is reduced, after a predetermined time has elapsed from the time of the instruction. Increase the air volume.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. The vehicle air conditioner according to the present invention, as shown in FIG. 2, is a compressor for a compression refrigeration cycle including a variable displacement compressor 2, a condenser 3, an evaporator 4, a liquid tank 5, and an expansion valve 6 driven by an engine 1. The laser unit 100 is provided. Variable displacement compressor 2
When the suction pressure exceeds the set pressure, the inclination angle is increased to increase the discharge capacity, and the set pressure is controlled by the solenoid current supplied from the CPU 41 shown in FIG. Further, the evaporator 4 is arranged in an air conditioning duct 7 having an outside air introduction port 7a and an inside air introduction port 7b (collectively referred to as an intake port). Each inlet 7a, 7b
An intake door (inside / outside air switching door) 8 that controls the flow rate of air introduced into the air conditioning duct 7 is provided in the vehicle. By opening and closing the intake door 8, the above-mentioned outside air introduction and inside air circulation are switched.

Further, in the air conditioning duct 7, as is well known, a blower fan 9, a heater core 10 and an air mix door 11 are provided.
And a vent door 12 and a foot door 13 that adjust the amount of air blown from the vent outlet 7c and the foot outlet 7d provided in the air conditioning duct 7, respectively. Further, a defroster door 14 is provided at the defroster outlet 7e provided in the air conditioning duct 7. Here, the bend outlet 7c is for blowing air toward the upper half of the occupant, the foot outlet 7d is for blowing air toward the occupant's feet, and the defroster outlet 7e is
It is for blowing air toward the window glass.

FIG. 3 is a block diagram showing a control system of the vehicle air conditioner. The CPU 41, via the input circuit 42, has an outside air temperature sensor 43 for detecting the outside air temperature Tamb, an indoor temperature sensor 44 for detecting the vehicle interior temperature Tinc, and an insolation Qs.
A solar radiation sensor 45 that detects un is connected, and various temperature information and heat quantity information (this corresponds to the vehicle heat load) are input to the CPU 41 from these sensors 43 to 45.

Further, the input circuit 42 includes an auto switch 51, an economy switch 52, an off switch 53, an ignition switch 54, a differential switch 55, and a REC switch 56 provided on a control panel of a driver's seat.
And the air volume setting switch 57 is connected. The auto switch 51 is a switch for instructing normal auto control, the economy switch 53 is a switch for instructing fuel saving and power saving auto control, and the off switch 53 is a switch for instructing on / off of the blower fan. Is. The diff switch 55 is a switch for instructing selection of the defroster outlet 7e, and the REC switch 56 is a switch for instructing internal air circulation. The air volume setting switch 57 is a switch for manually instructing the blower fan air volume, and in the present embodiment, the first speed, the second speed, the third speed, and the fourth speed can be selected in ascending order of the air volume.

The CPU 41 is also connected via an output circuit 49 to an air mix door actuator 61, a vent door actuator 62, a foot door actuator 63, a defroster door actuator 64, an intake door actuator 65 and a blower fan control circuit 66, and a blower fan control circuit 66. A motor (blower fan motor) 9 a for driving the blower fan 9 is connected to the fan control circuit 66. The blower fan motor 9a rotates at a speed according to the voltage applied from the blower fan control circuit 66, and blows out an air volume according to the rotation speed into the vehicle interior. The compressor 2 is further connected to the output circuit 49 via a relay 67.

Next, the procedure of the air conditioning control executed by the CPU 41 will be described with reference to the flow charts of FIGS. FIG. 4 is a main flowchart, and first, step S1
Initialization is performed at 0, and in the normal auto air conditioner mode, for example, the set temperature Tptc is initially set at 25 ° C. In step S20, various information from each sensor is input. The data information of each of these sensors will be specifically described. The set temperature Tptc is from a control panel (not shown), the vehicle interior temperature Tinc is from the indoor temperature sensor 44, the outside air temperature Tamb is from the outside air temperature sensor 43, and the amount of solar radiation Qsun is the amount of solar radiation. Each is given from the sensor 45.

Next, in step S30, the outside air temperature sensor 4
The outside air temperature Tamb obtained from No. 3 is processed to a value Tam corresponding to the actual outside air temperature by removing influences from other heat sources. In step S40, the solar radiation amount information as the light amount from the solar radiation sensor 45 is processed into a value Q'sun as a heat amount suitable for the subsequent conversion. In step S50, the set temperature Tptc set by the control panel is processed into a value T'ptc corrected according to the outside air temperature. In step S60, T'p
From tc, Tinc, Tam, Q'sun, Xm = (A + D) T'ptc + B * Tam + C * Q'sun-D * Tinc + E (however, A-E is a constant) and the target blowout temperature Xm is calculated. The actual opening of the air mix door 11 is controlled according to the opening Xm. The blowout temperature is determined by this air mix door opening degree control. Here, the target blowout temperature Xm decreases as the vehicle heat load described above increases, and increases as the vehicle heat load decreases.

In step S70, the compressor 2 that pressure-feeds the refrigerant to the evaporator 3 is controlled. Step S
At 80, the air outlets are controlled by the actuators 62, 63 and 64. Next, at step S90, the intake door 8 is driven by the intake door actuator 65 to perform suction port control, that is, switching control between outside air introduction and internal air circulation. In step S100, the blower fan air volume is controlled by controlling the voltage applied to the blower fan motor 9a. Then, the process returns to step S20.

FIG. 5 shows details of the suction port control in step S90. First, if it is determined in step S902 that the diff switch 55 has been turned from off to on, then step S902
Proceed to 911 to select outside air introduction (FRE). That is, the intake door actuator 65 drives the intake door 8 to the position indicated by the solid line in FIG. 2 to open the outside air introduction port 7a. When step S902 is denied, it progresses to step S903, and when it determines with the REC switch 56 being ON in step S903, it progresses to step S905.

If it is determined in step S905 that the compressor 2 has been switched from on to off, the process proceeds to step S911, and if not, the inside air circulation (REC) is selected in step S906. That is, the intake door actuator 65 drives the intake door 8 to the position indicated by the alternate long and two short dashes line in FIG. 2 to open the inside air introduction port 7b. If it is determined in step S903 that the REC switch 56 is off, the flow advances to step S904 to determine the on / off state of the compressor. If it is off, the process proceeds to step S911, and if it is on, the process proceeds to step S907.

In step S907, one of REC, 20% FRE, and FRE is selected from the illustrated characteristics based on the target outlet temperature Xm calculated in step S60 of FIG. Then, in step S908, it is determined which is selected, and if REC, the process proceeds to step S909 to select the inside air circulation, and if FRE, the above step S908.
Proceed to 911 to select the introduction of outside air. Also 20% FRE
In this case, the process proceeds to step S910, and the intake door 8 is drive-controlled so that the outside air is introduced by 20% and the inside air is introduced by 80%. After steps S909 to S911, the process returns to the process of FIG.

The above is the procedure for controlling the suction port. According to this procedure, when the REC switch 56 is off and the compressor 2 is on, the suction port is normally controlled based on the target outlet temperature Xm. Also in this state R
When the EC switch 56 is turned on, normally, the internal air circulation is forcibly selected.

6 to 8 are a subroutine flow chart showing the details of the air flow rate setting control in step S100 (FIG. 4). First, in step S101 of FIG. 6, the on / off state of the off switch 53 is determined. If it is on, the blower fan motor 9a is stopped in step S134 to return to the process of FIG. 4, and if it is off, the process proceeds to step S102. When it is determined in step S102 that the air volume setting switch 57 is operated (ON), step S10
3, the blower fan voltage Vf 'is set to 4.0 (LO) in step S106 when it is determined in step S103 that the first speed is commanded by the air volume setting switch 57.
And If it is determined in step S104 that the second speed is instructed, the blower fan voltage Vf 'is set to 6.0 (ML) in step S107, and step S105 is performed.
If it is determined that the third speed is instructed in step S108, the blower fan voltage Vf 'is set to 9.0 (MH) in step S108.
And Furthermore, if step S105 is denied, that is, if the fourth speed is commanded, step S109
Then, the voltage Vf ′ is set to V _ACC (maximum voltage). After that, the process proceeds to step S112 in FIG.

On the other hand, if it is determined in step S102 that the air volume setting switch 57 is off, the process proceeds to step S110 in FIG. 7 and variables L, M, N, P are set to L = -8 M = 20 N = 31 in step S110. With P = 75, the process proceeds to step S111. In step S111, the voltage V is calculated based on the target outlet temperature Xm from the characteristic shown in the figure.
f '(voltage applied to the blower fan motor 9a) is determined, and the process proceeds to step S112.

According to this characteristic, the voltage Vf 'is constant when the target blowout temperature Xm is within the predetermined range, but when Xm is larger than this predetermined range, the larger Xm is, that is, the vehicle heat load is smaller. Vf 'becomes larger as it goes. On the other hand, when Xm becomes smaller than the predetermined range, Vf 'becomes larger as Xm becomes smaller, that is, as the vehicle heat load becomes larger. This means that it is necessary to increase the blower fan air volume to obtain stronger heating as the vehicle heat load is smaller, and to increase the blower fan air volume to obtain stronger cooling as the vehicle heat load is larger. by.

In step S112, it is determined whether or not the outside air introduction is selected. If it is determined that the outside air introduction is not selected, that is, the inside air circulation is selected, step S11.
3, the timer Tvr is stopped and reset, and the process proceeds to step S114. This timer will be described later.

If it is determined in step S114 that the REC switch 56 is off, the process proceeds to step S117 and the voltage V
When f ″ is set to Vf ″ = Vf ′ and it is determined that the REC switch 56 is on, the process proceeds to step S115. If the determined voltage Vf ′ is determined to be 10.5 or more in step S115, the process proceeds to step S117, and if it is less than 10.5 and is 8 or more (when step S116 is negative), step S11.
In step 8, Vf ″ = Vf′−1.5 is set, and when it is less than 8 (when step S116 is affirmed), Vf ″ = Vf′−1 is set in step S119 and the process proceeds to step S129 in FIG.

On the other hand, if it is determined in step S112 that the outside air introduction is selected, step S12 in FIG.
If it is determined that the timer Tvr is operating in step S120, the process proceeds to step S123. If it is determined that the timer Tvr is not operating, the process proceeds to step S125. In step S125, it is determined whether or not the REC switch 56 is switched from on to off, and if affirmative, step S122
Then, the timer Tvr is started and the process proceeds to step S123.

If it is determined in step S123 that 3 seconds have elapsed from the start of clocking, the timer Tvr is determined in step S124.
Is stopped and reset, the process proceeds to step S126, and if it is determined that 3 seconds have not elapsed yet, the process proceeds to step S115 in FIG. On the other hand, if step S121 is denied, the process proceeds to step S125, and step S1
25 auto switch 51 or economy switch 5
If it is determined that the No. 2 is turned on from the above step S
If not, the process proceeds to step S126.

In step S126, it is determined from the output of a speed sensor (not shown) whether the vehicle speed Vc exceeds 80 km / h. If the result is negative, the process proceeds to step S117 in FIG. 7, and if the result is affirmative, the process proceeds to step S127. move on. Step S
At 127, the value of δ is determined from the characteristic shown in accordance with the vehicle speed Vc, and at step S128, the voltage Vf ″ is obtained from Vf ″ = Vf′−δ. That is, the vehicle speed Vc is 80K
When it exceeds m / h, the voltage Vf ″ is decreased as the vehicle speed Vc increases.

Next, in step S129, if it is determined that the current blower fan applied voltage Vfout is equal to or higher than the obtained voltage Vf ", the flow advances to step S130 to determine whether or not the determined voltage Vf" is 4.0 or less. To determine. If step S130 is denied, the blower fan applied voltage Vfout is set to Vf ″ in step S131, and if affirmed, the applied voltage Vfout is set to 4.0 in step S132.

On the other hand, if it is determined in step S129 that the current blower fan applied voltage Vfout is less than Vf ", the process proceeds to step S133 to increase the applied voltage Vfout to Vf", and Vfout = Vfout + Fv (Vf "-Vfout ) Is used to obtain a new applied voltage Vfout, where Fv is a function that increases with the passage of time, and therefore according to the above equation, the applied voltage Vfout gradually increases, not at once. . Steps S131 to S13
The applied voltage Vfout determined by any one of 3 is applied to the blower fan motor 9a, and the blower fan 9 rotates at a speed according to the applied voltage Vfout. Then, the air volume corresponding to the rotation speed is blown into the vehicle interior. After that, the process returns to the process of FIG.

According to the above procedure, when the air volume setting switch 57 is not operated at the time of setting the outside air introduction, the voltage Vf 'depending on the target outlet temperature Xm, that is, the heat load of the vehicle.
(= Vf ″) is determined, the blower fan applied voltage Vfout (normally Vfout = Vf ″) is determined based on this, and the air volume of the blower fan 9 is controlled. Then, when the REC switch 56 is turned on in this state to instruct the internal air circulation, based on the determined voltage Vf ′, step S
The voltage Vf ″ is determined as indicated by 115 to S119. Specifically, when (1) Vf ′ ≧ 10.5, Vf ″ = Vf ′ (2) 8 ≦ Vf ′ <10.5 Sometimes Vf ″ = V
f′−1.5 (3) When Vf ′ <8, Vf ″ = Vf′−1.

Here, the voltage Vf 'is the target outlet temperature X
Since it is obtained from the characteristics of step S111 (FIG. 7) based on m, a small Vf ′ indicates that the vehicle heat load is within a predetermined range (the indoor temperature is almost comfortable). , Vf ′ is large, it means that the vehicle heat load is higher or lower than a predetermined range. Therefore, according to the control of steps S115 to S119, when the vehicle heat load is within the predetermined range when the switch from the outside air introduction to the inside air circulation is instructed (in the cases of (2) and (3) above). The blower fan air volume is reduced, and when the vehicle heat load is smaller or larger than this range (case (1) above), that is, when powerful cooling or heating is required, the blower fan air volume is not reduced. Therefore, in the cases of (2) and (3), the fan noise can be reduced as in the conventional case. In this case, since the room temperature is almost comfortable,
Even if the fan air volume is reduced, the cooling performance or the heating performance is not significantly impaired. On the other hand, in the case of (1), the fan noise is not reduced because the blower fan air volume is not reduced, but the cooling performance or the heating performance is not degraded.

Further, such steps S115 to S11
The control of 9 is also performed when the fan wind speed (any one of the first speed to the fourth speed) is set according to the operation of the air flow setting switch 57 (air flow command). In this case, Vf "
At the 4th speed setting, where the maximum voltage is V _ACC (> 10.5), the air volume is not reduced from the outside air introduction to the inside air circulation switching.
When the speed is lower than or equal to the speed, the fan air volume is reduced according to Vf ″. That is, the fact that the 4th speed is set by the occupant is when a considerably strong cooling or heating performance is desired. Similar to the above, the fan air volume is not reduced.

Further, particularly in the present embodiment, when the blower fan air volume is reduced at the time of switching from the outside air introduction to the inside air circulation, the reduction amount is divided into two stages as shown in the above (2) and (3), and the vehicle heat is reduced. As the load deviates from the predetermined range, that is, the stronger cooling capacity or heating capacity performance is required, the reduction amount of the blower fan air flow is reduced. As a result, even when the air flow rate of the blower fan is reduced, it is possible to minimize the deterioration of the cooling performance and the heating performance. It should be noted that this control is not limited to two steps, and if it is divided into three steps or more, finer control can be performed.

Further, according to the above procedure, when the REC switch 56 is turned off from the on state (step S121) after the blower fan air flow is reduced by switching from the outside air introduction to the inside air circulation (step S121), the timer is started for 3 seconds. Until the time elapses, the process from step S115 is continued, and if the vehicle speed is 80 km / h or less after 3 seconds, the process of step S117 is performed. That is, a process of increasing the air volume to the original state (the state before the reduction) is performed 3 seconds after the switching to the outside air introduction is instructed. The reason for performing this control will be described below with reference to FIG.

That is, when the switching operation from the inside air circulation to the outside air introduction is performed, it takes time t1 for the intake door 8 to switch from the inside air circulation position to the outside air introduction position, as shown by L1 in FIG. In the example, this is about 3 seconds). On the other hand, since the blower fan air volume can be switched in a relatively short time by changing the fan applied voltage, if the fan applied voltage is increased at the same time as the switching operation from the internal air circulation to the external air introduction, as shown by a broken line L12, for example. The blower fan's air volume immediately rises, and the air volume will be increased before outside air introduction is set.
For this reason, the fan noise is increased during the time period indicated by t2, which gives an occupant a discomfort. Therefore, in this embodiment, the solid line L11
As shown in Fig. 4, the air volume is increased after waiting for the time (3 seconds) from the command of the internal air circulation to the setting of the external air introduction. I try not to give a pleasant feeling.

In the configuration of the above embodiment, the REC switch 56 is the command means 101, and the intake door 8 and the intake door actuator 65 are the switching means 102.
The CPU 41 controls the air volume control means 104 and the determination means 1
05 respectively.

In the above, steps S115 and S11 are performed.
As shown in 6, it is determined whether the vehicle heat load is within a predetermined range.
Although it is performed by determining the voltage Vf ′ determined in step S111, the present invention is not limited to this, and may be performed by determining the target outlet temperature Xm, for example. The threshold value of Vf ′ used in steps S115 and S116 is not limited to 10.5 or 8. Furthermore, the delay time for increasing the air volume at the time of the command to switch from the inside air circulation to the outside air introduction is not limited to 3 seconds.

[0037]

According to the first aspect of the present invention, in the blower fan air amount controlled in accordance with the heat load of the vehicle, when the switch from the outside air introduction to the inside air circulation is instructed, the vehicle heat load falls within the predetermined range. The air volume of the blower fan is reduced only when it is determined that the air flow from the outside air is introduced in the same way as before when the vehicle heat load is moderate (when strong cooling and heating are not required). The fan noise when switching the internal air circulation can be reduced, and when the vehicle heat load is considerably high (when strong cooling is required) or when it is considerably low (when strong heating is required), the air volume of the blower fan can be reduced. Without being reduced, it is possible to prevent a decrease in cooling performance or heating performance. Further, in particular according to the invention of claim 2,
When it is determined that the vehicle heat load is within the predetermined range when the switching from the outside air introduction to the inside air circulation is instructed, the air flow reduction amount of the blower fan is reduced as the vehicle heat load deviates from the predetermined range. Even if the blower fan air volume is reduced, it is possible to minimize the deterioration of the cooling performance and the heating performance. Further, according to the invention of claim 4, in the case where the air volume of the blower fan is set in accordance with the air volume command from the outside, switching from outside air introduction to inside air circulation is instructed, and the air volume of the blower fan is less than a predetermined value. When the determination is made, the air volume of the blower fan is reduced, so that the same effect as in claim 1 can be obtained. Further, according to the invention of claim 5, when the switching from the internal air circulation to the external air introduction is instructed after the air volume of the blower fan is reduced, the air volume is increased after a predetermined time has elapsed from the time of the instruction. Therefore, the air volume increases after the inside air circulation is completely switched to the outside air introduction, and it is possible to prevent the fan noise from increasing due to the increase in the air volume before the outside air introduction setting, and to eliminate the discomfort of the occupant.

[Brief description of drawings]

FIG. 1 is a diagram corresponding to a complaint.

FIG. 2 is a diagram showing a configuration of a vehicle air conditioner according to the present invention.

FIG. 3 is a block diagram showing a control system of the air conditioner.

FIG. 4 is a main flowchart showing a procedure of air conditioning control.

FIG. 5 is a subroutine flow chart showing details of suction port control.

FIG. 6 is a subroutine flowchart showing details of air volume control.

FIG. 7 is a flowchart following FIG.

FIG. 8 is a flowchart following FIG.

FIG. 9 is a time chart showing the opening degree of the intake door and the blower fan applied voltage when switching the suction port.

[Explanation of symbols]

2 compressor 7a Outside air inlet 7b Inside air inlet 8 intake door 9 Blower Fan 9a Blower fan motor 41 CPU 56 REC switch 65 intake door actuator 66 Blower fan control circuit 101 Command means 102 switching means 103 blower fan 104 Air volume control means 105 determination means

Claims (5)

[Claims] 1. A command means for instructing switching of outside air introduction for introducing air outside the vehicle compartment and inside air circulation for introducing air inside the vehicle compartment, and switching between the outside air introduction and the inside air circulation in accordance with the instruction of the instruction means. And a blower fan for blowing the introduced air into the passenger compartment, and controlling the air volume of the blower fan according to the heat load of the vehicle, and switching from outside air introduction to inside air circulation by the command means. When instructed, in a vehicle air conditioner including an air volume control means for reducing the air volume of the blower fan, a determination means for determining whether or not the vehicle heat load is within a predetermined range, the air volume control means Is the blower fan only when it is determined that the vehicle heat load is within a predetermined range when the instruction means instructs the switching from the outside air introduction to the inside air circulation. Vehicle air-conditioning apparatus characterized by reducing air flow. 2. The air conditioner for a vehicle according to claim 1, wherein the air flow control unit reduces the air flow reduction amount of the blower fan as the vehicle heat load deviates from a predetermined range. 3. The determination means determines whether the vehicle heat load is within a predetermined range based on a blower fan speed determined according to the vehicle heat load. Air conditioning system for vehicles. 4. Command means for instructing switching of outside air introduction for introducing air outside the passenger compartment and inside air circulation for introducing air inside the passenger compartment, and switching between the outside air introduction and the inside air circulation in accordance with the instruction of the instruction means. In a vehicle air conditioner comprising: a switching unit that performs the above, a blower fan that blows the introduced air into the vehicle compartment, and an air volume control unit that sets the air volume of the blower fan according to an air volume command from the outside. The blower fan set in the air volume control means comprises a determination means for determining whether the air volume is less than a predetermined value, the air volume control means, the command means is instructed to switch from outside air introduction to internal air circulation, An air conditioner for a vehicle, which reduces the set air volume of the blower fan when it is determined that the air volume of the blower fan is less than a predetermined value. 5. The air flow rate control means, when the air flow rate of the blower fan is reduced and then the switching from the internal air circulation to the external air introduction is instructed by the commanding means, the predetermined time has elapsed from the time of the instruction. The vehicle air conditioner according to any one of claims 1 to 4, wherein the air flow rate is increased.