JPH07102777B2 - Air conditioner for vehicle - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a vehicle air conditioner that detects humidity in a vehicle compartment and performs predetermined demist control when the detected humidity reaches a predetermined value.

(Prior Art) In the conventional air conditioner for a vehicle,
As disclosed in Japanese Patent No. 11, the dew condensation sensor detects the cloudy state of the windshield and the like, and activates the cooling device.
In addition, it is known to perform demist control by switching the operation mode to dehumidification.

Further, as disclosed in Japanese Utility Model Application Laid-Open No. 57-177808, it is known that the compressor is driven and the blower is driven when the humidity detected by the humidity sensor is equal to or higher than a predetermined humidity. .

(Problems to be Solved by the Invention) In the conventional example described above, when the detected humidity reaches the detected value, it is determined that the vehicle window has become cloudy, and the compressor of the cooler is put into the operating state, and intake air and blown air Demist control such as mode switching is performed.

However, the detected humidity for determining that the car window is cloudy is constant. However, the correlation between the output of the humidity sensor that detects the humidity in the vehicle interior, that is, the detected vehicle interior humidity and the degree of fog on the windshield differs depending on whether or not air is being blown from the defrost outlet. As a result, if the dew condensation level is determined assuming, for example, that winter defrost / heat or defrost mode is cloudy, the windshield is not exposed to warm air in the heat mode (no air is blown from the defrost). Therefore, since the temperature of the humidity sensor attached to the glass surface is low and the output level of the humidity sensor is low, there is a problem that the demist control is not started unless the windshield is completely fogged.

On the contrary, if the dew condensation level is determined in the heat mode, the demist control is started even though the windshield is scarcely clouded in the defrost / heat or defrost mode. there were.

It is an object of the present invention to provide a vehicle air conditioner that solves the above problems.

(Means for Solving Problems) The present invention has the following structure in order to solve the above problems.

An air conditioner for a vehicle, comprising humidity detecting means for detecting the humidity inside the vehicle, and performing a predetermined demist control when the humidity detected by the humidity detecting means reaches a predetermined value. I changed it according to the mode.

(Operation) Therefore, in the air blowing mode in which there is no movement of air along the vehicle window, especially the windshield inner surface, the predetermined set value is set low, and in the blowing mode in which there is a lot of air movement, it is set high. By changing the predetermined set value, the correlation between the output of the humidity detecting means and the cloudiness of the vehicle window does not change depending on the air blowing mode.

(Examples) Hereinafter, the present invention will be described with reference to Examples.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

11 is the air conditioner body, 12 is the air conditioner body 11
Is a control device for controlling the. The air conditioner main body 11 has an intake door 14, a blower 15, an evaporator 16, a mix door 17, and a heater core 18 which are sequentially arranged from the upstream side of the duct 13, and the air outlets 29, 30 to 20 on the most downstream side. , 31 and the air outlets 29, 30, 31 are provided with a mode switching door 19.

The intake door 14 is switched by a motor actuator 32 and is driven to select one of an all-outside air introduction position, a vehicle interior air introduction position or a partial outside air introduction position. When the partial outside air introduction position is selected, the outside air and the vehicle interior air are mixed and sucked. The air sucked by the blower 15 through the intake door 14 passes through the evaporator 16 and is cooled when the cooler 26 including the evaporator 16 is in operation.

22 is a compressor, 23 is a conde sensor, 24 is a receiver tank, 25 is an expansion valve, and it is a cooler together with the evaporator 16.
Makes up 26. In-vehicle internal combustion engine output shaft rotation is pulley
Has been transmitted to 27. The rotation of the pulley 27 is transmitted to the compressor 22 via the magnet clutch 28, and this transmission drives the compressor 22.

The heater core 18 has introduced therein the cooling water of the vehicle-mounted internal combustion engine and acts as a heater. The mix door 17 is driven by the motor actuator 33, and depending on the opening degree of the mix door 17, the amount of air passing through the evaporator 16 is increased by the heater core.
The amount of air passing through 18 is controlled.

On the other hand, as will be described later, the blower is controlled by the output from the controller 12.
The air flow rate of 15, the operation time and period of the cooler 26, and the opening degree of the mix door 17 are controlled individually in accordance with the values related to the deviation between the air temperature inside the vehicle and the set temperature, and the air temperature inside the vehicle is controlled. Controlled to desired temperature.

The air outlet 29 is a defrost outlet that blows air along the inner surface of the windshield, the air outlet 30 is a vent outlet that blows air toward the occupant's face, and the air outlet 31 is air from the feet of the occupant. A heat outlet for blowing out is formed, and the air outlets 29, 30, 31 are selected by the mode switching door 19. Defrost mode in which only vent outlet 29 is selected by mode switching door 19, vent mode in which only vent outlet 30 is selected, heat outlet
One of the heat mode in which only 31 is selected, the bi-level mode in which the vent outlet 30 and the heat outlet 31 are selected, and the defrost / heat mode in which the defrost outlet 29 and the heat outlet 31 are selected are selected. Bi-level mode is referred to as B / L mode, and defrost / heat mode is referred to as D / H mode. The mode switching door 19 is driven by the actuator 34.

In FIG. 1, reference numerals 46 to 50 are drive circuits for driving the motor actuator 32, the blown air 15, the magnet clutch 28, the motor actuator 33, and the motor actuator 34, respectively.

Inside air temperature detection sensor 36 for detecting vehicle interior temperature, solar radiation amount detection sensor 37 for detecting solar radiation amount, evaporator outlet air temperature detection sensor 38 for detecting evaporator outlet air temperature, that is, temperature at point A, outside air temperature for detecting outside air temperature Detection sensor 39, potentiometer 41 that detects the opening of the mix door 17, temperature setter 40 that sets the passenger compartment temperature, and passenger compartment 20
A humidity detecting sensor 42 for detecting the internal temperature is provided. Output of inside air temperature detection sensor 36, output of solar radiation amount detection sensor 37, output of evaporator outlet air temperature detection sensor 38, output of outside air temperature detection sensor 39, set output of temperature setter 40,
The output of the humidity detection sensor 42 and the output of the potentiometer 41 are supplied to an A / D converter (hereinafter referred to as ADC) 43 through a multiplexer (not shown), converted into digital data, and converted by the ADC 43. The data is supplied to a microcomputer 21 forming a part of the control device 12.

Further, the microcomputer 21 is supplied with the output of the mode manual changeover switch 35 that manually switches to the desired air blowing mode, and the mode manual changeover switch 35 defrost mode, D / H mode, heat mode, B / L mode, One of the vent modes is instructed to be selected.

The microcomputer 21 basically has a CPU, a ROM storing a program, a RAM storing data, an input port and an output port. The output digital data of ADC43 is read from the input port according to the program stored in ROM, processed by the CPU according to the program stored in ROM, and the calculated data is sent to the drive circuits 46 to 50 through the output port. Is output.

The operation of one embodiment of the present invention will be described with reference to the programs stored in the ROM with reference to the flowcharts shown in FIGS.

When the program is started, initial settings such as clearing the RAM are made (step a), then the digital data from the ADC 43 is read and stored in a predetermined area of the RAM (step b). Following step b, T = T _R + K ₁ T _S +
Comprehensive data _{K 2 T A + K 3 T} E -K 4 T D + K 5 is computed (step c). Here, T _R is the vehicle interior temperature, T _S is the amount of solar radiation, T _A is the outside air temperature, T _E is the evaporator outlet air temperature, T _D is the set temperature, K _{1 to} K ₅ are constants, and the total data T is Cabin temperature
It corresponds to a value obtained by correcting the deviation between T _R and the set temperature of the temperature setter 40 by the amount of solar radiation, the outside air temperature, and the evaporator outlet air temperature.

Following step c, a known blower control is performed to control the blower 15 via the drive device 47 having an air flow corresponding to the total data T (step d). After step d, the mix door 17 is controlled to an opening degree corresponding to the comprehensive data T via the drive circuit 49, and the magnet clutch 28 is controlled to be energized or deenergized via the drive circuit 48 to cool the machine 26. The operating time and period are controlled, and a known temperature control for controlling the temperature inside the vehicle interior to a desired value is performed (step e).
Following step e, data of T _F = T _E + K ₆ θ + β is calculated (step f). Here, θ is the opening of the mix door, K ₆ is a constant, β is a correction value, and the data T _F corresponds to the temperature of the air blown into the passenger compartment 20. Further, θ = 100% is the opening when the entire air passing through the evaporator 16 is passed through the heater core 18.

Following step f, the air blowing mode is switched to the mode switching door 19 corresponding to the data T _F to select the air outlet (step g).

As is well known in the mode control in step g, the mode switching damper 19 is selected to select one of the defrost mode, D / H mode, heat mode, B / L mode, and vent mode in accordance with the data T _F. Made by the control of.

The same applies when the mode is instructed by the mode manual changeover switch 35.

Demist control is performed following step g (step h), and step b is performed following step h.

When the demist control is started, it is checked whether or not the temperature detected by the humidity detecting sensor 42 is α ₁ or more, and when the detected temperature is less than α ₁ , the demist control is substantially bypassed (step g ₁ ). In this case, the detected humidity is low, and it is determined that the windshield is not clouded regardless of the air blowing mode, and there is no need to perform demist. If the detected humidity is α ₁ or more in step g ₁ , it is checked whether the air blowing mode is a mode other than the defrost mode or the D / H mode (step g ₂ ).
Step g detected humidity after step g ₂ When it is determined that the defrost mode or D / H mode at ₂ alpha ₂
It is checked whether or not (α ₂ > α ₁ ) or more (step
g ₃ ). When the detected humidity is α ₂ or more in step g ₃ , the demist routine (step j) is executed.

When it is determined in step g ₂ that the air blowing mode is a mode other than the defrost mode and the D / H mode,
That is, when it is determined that the mode is the B / L mode, the heat mode, or the vent mode, step j is executed after step g ₂ .

When the detected humidity is less than α ₂ in step g ₃ , the same as when the detected humidity is less than α ₁ in step g ₁ .
The demist routine j is bypassed. In this case, it is determined that the windshield is not cloudy in the defrost mode and the D / H mode.

Heat mode As seen from the above, B / air flow flowing along inner surface of the windshield when the L-mode and the vent mode is small, the windshield is in state easy cloudy de-misting at the detected humidity alpha ₁ or more in this case The routine will be executed. This state is shown by the solid line in FIG. In the defrost mode and the D / H mode, the air flow rate along the inner surface of the windshield is large and the windshield is not easily fogged. In this case, when the detected humidity α ₂ or higher which is higher than the detected humidity α ₁ , The mist routine will be executed. This state is the fifth
It is indicated by a broken line in the figure. That is, the fog determination humidity of the windshield for which the demist routine should be executed is changed in accordance with the air blowing mode.

Next, the demist routine j will be described.

When the demist routine j is entered, it is determined whether or not the outside air temperature T _A is equal to or higher than a predetermined temperature W (step j ₁ ), and when the temperature is lower than the temperature W, it is determined whether or not the change in the detected humidity exceeds β (step j ₂ ) If the change exceeds β, the defrost mode is set and the fresh mode is set to control the opening of the intake door 14 so that the outside air is introduced (step j ₃ ). Thus air defrost mode if step j ₁ to j ₃ is performed is flowed along the windshield inner surface, the windshield fogging is Harasa.

When the temperature is equal to or higher than the temperature W in step j ₁ , it is checked whether or not the outside air temperature is equal to or higher than the set intermediate season temperature X (X> W) (step j ₄ ), and when the temperature is lower than the temperature X, the D / H mode is set,
In addition, the fresh mode is set to control the opening of the intake door 14 so that the outside air is introduced (step j ₅ ).
The change in the detected humidity in step j ₂ is when the following β Step j ₅ Following Step j ₂ is executed. In this case, the fogging of the windshield is not as steep as in the case of steps j _{1 to} j ₃ , and in the D / H mode and by introducing the outside air, the windshield is fogging.

Outside air temperature T _A in step j ₄ is when the above temperature X outside air temperature T _A is checked whether the temperature Y (Y> X) or more during the rainy season (Step j _6), step time of less than aloud Y
j ₅ is executed. Step When the above temperature Y after step j ₆ in j ₆ outside air temperature T _A is summer temperature Z (Z>
Y) or more is checked (step j ₇ ) and the temperature Z
If less, the cooler 26 is driven via the magnet clutch 28 and brought into the outside air introduction state (step j ₈ ).
In this state, the outside air is dehumidified and air-conditioned, and the windshield is clouded.

When the outside air temperature T _A is equal to or higher than Z in step j ₇ , the cooler 26 is driven via the magnet clutch 28 and the opening degree of the intake door 14 is controlled so as to be in the internal regulation circulation state (step j ₉ ). . In this case, the air inside the vehicle is dehumidified and air-conditioned, and the windshield is fogged.

In the above, the temperatures W, X, Y, and Z are actually provided with hysteresis widths of ΔW, ΔX, ΔY, and ΔZ, respectively, and switching of j ₃ , j ₅ , j ₈ , and j ₉ is not frequent. It is desirable to do so, and it is shown in FIG. 4 with hysteresis.

The demist routine is an example, and it goes without saying that it may be executed by another program.

Further, in the above-described embodiment, the case where the microcomputer 21 is used has been described as an example, but the present invention can be implemented without using the microcomputer.

(Effects of the Invention) As described above, according to the present invention, when the detected vehicle interior humidity reaches a predetermined set value, in the vehicle air conditioner that performs a predetermined demist control, the predetermined set value is supplied to the vehicle interior. Since the change is made according to the air blowing mode, the demist control can be performed at an appropriate time with respect to the correlation between the detected vehicle interior humidity and the fogging of the vehicle window, which changes depending on the air blowing mode.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. 2 to 4 are flowcharts for explaining the operation of one embodiment of the present invention. FIG. 5 is a diagram for explaining the operation of one embodiment of the present invention. 14 …… Intake door, 15 …… Blower, 16 …… Evaporator, 19 …… Mode switching door, 20 …… Car interior, 26 …… Cooler, 29 …… Air outlet, (Defrost outlet), 30
〜31 …… Air outlet, 32-34 …… Motor actuator, 36 …… Inside air temperature detection sensor, 37 …… Insolation detection sensor, 38 …… Evaporator outlet air temperature detection sensor, 39…
… Outside air temperature sensor, 42 …… Humidity sensor, 46-50
...... Drive circuit.

Claims (2)

[Claims] 1. An air conditioner for a vehicle, comprising: humidity detecting means for detecting the humidity inside a vehicle; and performing a predetermined demist control when the humidity detected by the humidity detecting means reaches a predetermined value. An air conditioner for a vehicle, characterized in that it is changed according to an air blowing mode to a room. 2. The vehicle air conditioner according to claim 1, wherein the predetermined value is changed depending on whether or not air is being blown from the defrost outlet.