JPH04129826A - Air conditioner for vehicle - Google Patents

Abstract

PURPOSE:To prevent an unpleasant feeling due to the fact that blowoff temperature is high by enabling an air volume controlling means to control a driving means to reduce the air volume of a blower fan more than normal in response to the inhalation temperature when the temperature inside a car room is below the specified temperature and the inhalation temperature exceeds a specified value. CONSTITUTION:When the indoor temperature TINC is below 30 deg.C, the inhalation temperature TINT is judged whether it is not more than 15 deg.C or not. When negatively judged, namely, the inhalation temperature exceeds a specified value, impressed voltage Vf'' is determined by a formula of Vf''=Vf'-(TINT-15)...(1). Then, the impressed voltage Vf''is impressed to a blower fan motor 9a through a blower fan control circuit 65 to drive a blower fan at a speed responding to that voltage Vf''. On the other hand, when the temperature inside a car room is below 30 deg.C and the inhalation temperature exceeds 15 deg.C, the impressed voltage Vf'' is determined by the formula. If this formula is observed, the higher the inhalation temperature TINT is, the more the impressed voltage Tf'' is lowered reducing air volume of the blower fan.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a vehicle air conditioner having a blower fan and an evaporator.

B. Conventional technology Vehicle air conditioners have been known that include a blower fan and an evaporator that cools the air from the blower fan, and that control the air volume of the blower fan depending on the vehicle heat load (for example, outside temperature and amount of solar radiation). (For example, "Service Bulletin JN0.578 (June 1986)" published by 8 San Jidosha).

C0 Problems to be Solved by the Invention However, immediately after the air conditioner is activated, the cooling capacity of the evaporator is not sufficient. Therefore, if the air volume of the blower fan is large, the air cannot be cooled sufficiently by the evaporator, and the blowing temperature may decrease. There was a problem in that the air pressure became high, and as a result, the passengers felt uncomfortable.

An object of the present invention is to provide a vehicle air conditioner that prevents discomfort caused by high blowout temperature.

Means for Solving Problems No.90 To explain with reference to FIG. 1, which is a diagram corresponding to the claims, the present invention comprises a blower fan 101, a driving means 102 for driving the blower fan 101, and an evaporator for cooling air from the blower fan 101. 103, and an air volume control means 104 that controls the drive means 102 to control the air volume of the blower fan 101 according to the vehicle heat load. The above problem is solved by comprising a suction temperature sensor 105 that detects the suction temperature downstream of the evaporator 103 and an indoor temperature sensor 106 that detects the temperature inside the vehicle, and by configuring the air volume control means 104 as follows. .

That is, when the vehicle interior temperature is below a predetermined temperature and the suction temperature exceeds a predetermined value, the air volume control means 104 controls the drive means 102 to reduce the blower fan air volume compared to normal according to the suction temperature.

80 action When the vehicle interior temperature is less than a predetermined temperature and the suction temperature exceeds a predetermined value, the air volume of the blower fan 101 is reduced compared to normal according to the suction temperature (air temperature downstream of the evaporator 103). As a result, if the cooling capacity of the evaporator 103 is insufficient, the air volume of the blower fan 101 decreases, and this reduction in air volume lowers the blowing temperature to a level that does not cause discomfort to the occupants. Furthermore, when the temperature inside the vehicle is higher than a predetermined temperature, the air volume is set to the normal air volume in order to increase the cooling capacity.

In the above-mentioned sections and section E, which describe the present invention in detail, figures of embodiments are used to make the present invention easier to understand, but the present invention is not limited to the embodiments.

F. Example An embodiment of the present invention will be described with reference to FIGS. 2 to 5.

As shown in FIG. 2, the vehicle air conditioner according to the present invention has the following features:
Variable displacement compressor 2 driven by engine 1
．． Capacitor 3. Evaporator 4° liquid tank 5.
A compression refrigeration cycle cooler unit 100 including an expansion valve 6 is provided.

The variable capacity compressor 2 increases the discharge capacity by increasing the inclination angle when the suction pressure exceeds the set pressure. Controlled by SQL. Further, the evaporator 4 is disposed within an air conditioning duct 7 having an outside air introduction lower a and an inside air introduction lower b.

Each of the introduction lowers a, 7b is provided with an inside/outside air switching door 8 that controls the flow rate of air introduced into the air conditioning duct 7. Furthermore, inside the air conditioning duct 7, there is a well-known rib blower fan 9,
Heater unit h ] O, air mix door 11 is provided, and vents I provided in air conditioning ducts 1 to 7
- A vent door 12 and a foot 1-door 13 are provided for adjusting the amount of air from the air blowing lower c and the foot blowing lower d, respectively.

Furthermore, a defroster blowout lower e provided in the air conditioning duct 7
A defroster door 14 is provided.

The vent blowout lower c is for blowing air towards the upper body of the occupant, the foot blowout lower d is for blowing air towards the occupant's feet, and the defroster blowout lower e is for blowing air towards the window glass. It is for blowing out. After the air from the blower fan 9 is cooled by the evaporator 4, it is blown into the vehicle interior from each outlet.

FIG. 3 is a block diagram showing a control system of a vehicle air conditioner according to the present invention. The CPU 41 is connected via an input circuit 42 to an outside air temperature sensor 43 .
An indoor temperature sensor 441 that detects the vehicle indoor temperature TIN(:
A solar radiation sensor 45 that detects the solar radiation amount Q8LIN and a suction temperature sensor 46 that detects the air temperature (suction temperature) TINT downstream of the evaporator 4 are connected, and these sensors 43
- 46, various temperature information and heat amount information are input to the CPU 41.

Furthermore, the input circuit 42 includes an ignition switch 51.
is connected, as well as a defroster switch 52, an air volume setting switch 53, and an off switch 54 provided on the control panel of the driver's seat. The defroster switch 52 is a switch for commanding a defroster mode (mainly a mode in which air is blown out from the defroster blowing lower e), and the air volume setting switch 53 is a switch for manually commanding the air volume of the blower fan 9. In this embodiment, the first, second, and third speeds can be selected by operating the air volume setting switch 53. Further, the off switch 54 is a switch that is turned on when the operation of the blower fan 9 is stopped.

Furthermore, the CPU 41 is connected to an air mix door actuator 61 . Vent door actuator 62. A foot door actuator 63, a defroster door actuator 64, and a blower fan control circuit 65 are connected, and a motor 9a that drives the blower fan 9 is connected to the blower fan control circuit 65. Output circuit 4
9 is further connected to the compressor 2 via a relay 66.

Next, the control procedure by the CPU 4.1 will be explained based on the flowcharts of FIGS. 4 and 5.

FIG. 4 is a flowchart showing the basic control of the air conditioning control device executed by the CPU 4-1.

- This program is started when the ignition switch 51 is turned on, initial settings are made in step SIO, and in normal auto air conditioner mode, for example, the set temperature T
Initialize PTC to 25°C.

In step S20, various information from each sensor and switch is input.

To specifically explain these data information, the set temperature T
The PTC is determined from a control panel (not shown), the vehicle interior temperature TING is determined from the interior temperature sensor 44, and the outside air temperature TA is determined from the interior temperature sensor 44.
MB is from the outside temperature sensor 43, solar radiation QsυN is from the solar radiation sensor 45, suction temperature T [NT is the suction temperature sensor 4
It is given from 6.

Next, in step S30, the outside air temperature TAMB obtained from the outside air temperature sensor 43 is processed to a value TAM corresponding to the actual outside air temperature by removing the influence from other heat sources. Next, in step S40, the solar radiation amount information as the light amount from the solar radiation sensor 45 is converted into a value Q″S as the heat amount suitable for subsequent conversion.
Process to UN.

In step S50, the set temperature T PTC set on the control panel is corrected according to the outside temperature T'
Process to PTC.

In step S60, TINCt TAM+Q″SUN
(These correspond to the vehicle heat load) and T'PTC
The target blowout temperature To is calculated from
1 and control the blowing temperature.

In step S70, the compressor 2 is controlled.

In step S80, based on the target blowout temperature To, the vent door actuator 62. The foot door actuator 63 and the defroster door actuator 64 drive each door 7c, 7d, and 7e to control the air outlet.

In step S90, selection switching of the suction ports, that is, the outside air introduction lower a and the inside air introduction lower b is controlled.

In step 5100, the air volume from the outlet is controlled by controlling the blower fan 9 as described later. After that, the process returns to step S20, and the above-described process is repeated.

FIG. 5 is a flowchart showing details of the air volume control in step 5100 described above.

In FIG. 5, first, in step 5101, the state of the off switch 54 is determined. If the off switch 54 is on, the blower fan 9 is stopped in step 5102, and if it is off, it is determined in step 5103 whether or not the air volume setting switch 53 is operated. If the blower fan motor 9a has been operated, the process advances to step 5104, and the voltage applied to the blower fan motor 9a is determined based on the operating state.

That is, if the first speed is commanded, step 5104 is affirmed, and step 5106 sets the applied voltage to vl.

If 2 speed is commanded, step 5105 is affirmed and step 8107 changes the applied voltage to V2 (V2>V
l). Furthermore, if 3 speeds have been commanded, step 5105 is denied and the applied voltage is changed to V in step 8108.
3 (V3>v2). and step S]-09
Then, the above-determined applied voltage is applied to the blower fan motor 9a via the blower fan control circuit 65.

As a result, the blower fan 9 is driven at a speed (air volume) corresponding to the applied voltage.

On the other hand, if it is determined in step 5103 that the air volume setting switch 53 is not operated, the process proceeds to step 5Lio, where it is determined whether the defroster switch 52 is on. If it is off, the process proceeds to step 5112; if it is on, constants are set in step 5111, M, N, and P are changed, and the process proceeds to step 5112. That is, these constants R, M,
Although N and P are set to predetermined values in advance, they are changed when the defroster switch 52 is operated.

In step 5112, it is determined whether or not the vent mode (mainly the mode in which air is blown out from the vent blowout lower c) is set by the air outlet control in step 380. If the answer is negative, the process proceeds to step 5l14, and if the answer is affirmative, the process proceeds to step 5112. Then, in step 5113, a variable β is determined from the illustrated characteristics in accordance with the solar radiation correction value Q'5LIN, and the process proceeds to step 5114. In step 5114, the voltage Vf is determined from the illustrated characteristics according to the target blowing temperature To and the constants M, N, and P, and the process proceeds to step 5115. In step S1]-115, a variable α is determined from the characteristics shown in the figure in accordance with the outside temperature correction value TAM, and then in step S116, the voltage Vf' is determined by the following equation.

When in vent mode: Vf' = 5 + β + (Vf-
5-β)×αOther than vent mode: Vf' = 6+
β+(Vf-6)Xα Here, β in the vent mode is a value obtained from the characteristics of step 5113 above, and β in other than the vent mode is a preset value.

Next, the process advances to step 5117, and the indoor temperature TINC is 30.
Determine whether the temperature is below ℃. If this is denied, the process proceeds to step 5120, where the calculated voltage Vf' is applied as the applied voltage Vf'', and the process proceeds to step 5121; if affirmed, it is determined in step 5118 whether or not the suction temperature TINT is 15° C. or less.Step If 8118 is affirmed, the process proceeds to step 5120, and if negative, that is, if the suction temperature exceeds a predetermined value, in step 5119, Vf
The applied voltage Vf is obtained from "=Vf'-a (TINT-15)-(1)" and the process proceeds to step 5121. In step 5121, the blower fan control? The above step 5120 or 511 is performed via the control circuit 65.
The applied voltage Vf'' obtained in step 9 is applied to the blower fan motor 9a.
and drives the blower fan 9 at a speed (air volume) corresponding to the voltage Vf''.

According to the above procedure, Vf' is determined based on the voltage Vf obtained from the target blowing temperature To and the constants α and β,
In a normal case (when the vehicle interior temperature is 30° C. or higher or the suction temperature exceeds 15° C.), this Vf' is applied to the blower fan motor 9a as an applied voltage Vf'' to determine the blower fan air volume.

On the other hand, if the vehicle interior temperature is less than 30'C and the suction temperature is 15
℃, the applied voltage Vf
” is determined. According to this equation (1), the suction temperature T
The higher INT is, the smaller the applied voltage Vf" is, and the blower fan air volume is reduced. That is, when the cooling capacity of the evaporator 4 is not sufficient, the blower fan air volume is reduced accordingly, and thereby the rise in the blowing temperature is suppressed. This prevents discomfort from being caused to the occupants.

The reason why the normal air volume control is performed when the indoor temperature is 30° C. or higher is to quickly cool the vehicle interior.

In the configuration of the above embodiment, the CPU 41 and the blower fan control circuit 65 constitute the air volume control means 104.

Note that the equation for determining the applied voltage Vf'' is not limited to equation (1), and may be of any other form as long as the applied voltage ■f I+ becomes smaller as the suction temperature T INT becomes higher.

G0 Effects of the Invention According to the present invention, when the vehicle interior temperature is below a predetermined temperature and the suction temperature exceeds a predetermined value, the blower fan air volume is reduced compared to normal according to the suction temperature.
When the cooling capacity of the evaporator is insufficient, the air volume of the blower fan is reduced to suppress a rise in the blowing temperature, thereby eliminating discomfort to the occupants.

[Brief explanation of the drawing]

FIG. 1 is a complaint correspondence diagram. 2 to 5 show one embodiment of the present invention, FIG. 2 is an overall configuration diagram of a vehicle air conditioner according to the present invention, FIG. 3 is a block diagram showing a control system, and FIG. 4 is a main FIG. 5 is a flowchart illustrating details of air volume control. 4: Evaporator 9 Niblower fan 9a Niblower fan motor 41: CPU43: Outside temperature sensor
44: Indoor temperature sensor 45: Solar radiation sensor
46: Suction temperature sensor 65 Niblower fan control circuit 1o1 Niblower fan 102: Drive means 103:
Evaporator 104: Air volume control means 105; Suction temperature sensor 106: Indoor temperature sensor Patent applicant
Nissan Motor Co., Ltd. Representative Patent Attorney Fuyuki Nagai Figure 4

Claims (1)

[Scope of Claims] A blower fan, a drive means for driving the blower fan, an evaporator for cooling air from the blower fan, and an air volume for controlling the drive means to control the air volume of the blower fan according to a vehicle heat load. A vehicle air conditioner comprising: a suction temperature sensor that detects a suction temperature downstream of the evaporator; and an interior temperature sensor that detects a vehicle interior temperature; An air conditioner for a vehicle, characterized in that when the suction temperature is lower than the temperature and the suction temperature exceeds a predetermined value, the driving means is controlled to reduce the blower fan air volume compared to normal according to the suction temperature.